Stop snapshot purge when a snapshot cannot leave the local index (closes #337)

snapshot purge, and the purge step of snapshot create --prune, logged a
failed local index delete, then deleted that snapshot's metadata from
the destination store anyway and exited 0, leaving a local record whose
metadata was gone. It now stops at that snapshot with an error, before
touching its metadata, so the command exits non-zero; snapshots already
purged stay purged. This matches how the same loop already handles a
failed metadata delete.

Model: opus-5-5

ARCHITECTURE.md

@@ -311,8 +311,6 @@ Repository interfaces:
 
 ```
 CreateSnapshot(opts)
-    │
-    ├─► markDestination()   // Refuse a destination without the marker, then write it
     │
     ├─► PruneDatabase()   // Critical: avoid dedup errors
     │
@@ -369,8 +367,6 @@ CreateSnapshot(opts)
 
 ```
 bucket/
-├── vaultik-destination.txt          # Marker written by every backup
-│
 ├── blobs/
 │   └── {hash[0:2]}/
 │       └── {hash[2:4]}/
@@ -382,15 +378,6 @@ bucket/
         └── manifest.json.zst        # Blob list (for pruning/verification)
 ```
 
-While the local index holds snapshots, a destination without
-`vaultik-destination.txt` is treated as not present
-(`checkDestinationMarker` in `internal/vaultik/destination_marker.go`):
-`snapshot create` refuses to write to it, and listing it fails as for a
-destination that cannot be listed. An unplugged volume's empty mount point
-is therefore never taken for a destination whose snapshots are all gone.
-The `file://` backend never creates its destination directory, so a write
-to a missing one fails.
-
 The `{remote-key}` directory name is a one-way double SHA-256 hash of the human
 snapshot ID, so the human ID (hostname, snapshot name, timestamp) is never
 written to the store as a directory name. See

Dockerfile

@@ -5,7 +5,16 @@
 FROM golangci/golangci-lint:v2.14.0@sha256:ad862ba6b3798cbe0fd9fd7408d498fd74fbd2623a92406b2fd3898faf0bf98f AS lint
 WORKDIR /src
 COPY go.mod go.sum ./
-RUN go mod download
+# Without the time limit a stalled connection to the module proxy holds
+# this step, and every build on the host sharing it, until the kernel
+# drops the connection, which can take an hour. The limit is well above
+# the three minutes a working download can take on a busy build host.
+RUN for attempt in 1 2 3; do \
+        timeout 300 go mod download && exit 0; \
+        echo "go mod download attempt $attempt failed or ran over 300s" >&2; \
+    done; \
+    echo "module download failed: giving up after 3 attempts" >&2; \
+    exit 1
 COPY . .
 # `golangci-lint run` silently ignores an unknown top-level key in
 # .golangci.yml, such as a misspelt `linters:`; `config verify` fails on it.
@@ -18,7 +27,13 @@ RUN golangci-lint run --config .golangci.yml ./...
 FROM golang:1.26.1@sha256:cd78d88e00afadbedd272f977d375a6247455f3a4b1178f8ae8bbcb201743a8a AS test
 WORKDIR /src
 COPY go.mod go.sum ./
-RUN go mod download
+# Limited and retried as in the lint phase above.
+RUN for attempt in 1 2 3; do \
+        timeout 300 go mod download && exit 0; \
+        echo "go mod download attempt $attempt failed or ran over 300s" >&2; \
+    done; \
+    echo "module download failed: giving up after 3 attempts" >&2; \
+    exit 1
 COPY . .
 RUN go test -timeout 90s -race -cover ./... || \
     { echo "--- Rerunning with -v for details ---"; \
@@ -36,7 +51,13 @@ RUN apk add --no-cache git
 RUN git config --system --add safe.directory /src
 WORKDIR /src
 COPY go.mod go.sum ./
-RUN go mod download
+# Limited and retried as in the lint phase above.
+RUN for attempt in 1 2 3; do \
+        timeout 300 go mod download && exit 0; \
+        echo "go mod download attempt $attempt failed or ran over 300s" >&2; \
+    done; \
+    echo "module download failed: giving up after 3 attempts" >&2; \
+    exit 1
 COPY . .
 
 # The VERSION build arg when one is given, otherwise

README.md

@@ -24,10 +24,6 @@ grep 'public key' vaultik_backup_private_key.txt
 vaultik config set age_recipients.0 age1YOUR_PUBLIC_KEY_HERE
 vaultik config set storage_url "file:///Volumes/usbstick/mybackup"
 
-# create the destination directory; vaultik never creates it, so a backup
-# to a volume that is not plugged in fails instead of filling the disk
-mkdir /Volumes/usbstick/mybackup
-
 # macOS only: grant your terminal app Full Disk Access first
 # (System Settings → Privacy & Security → Full Disk Access), otherwise
 # the backup will abort with a permission error on protected directories
@@ -293,16 +289,13 @@ needed.
   this duration instead of only the latest (e.g. `4w`, `30d`, `6mo`, `1y`).
   Without `--prune`, or with a value that is not a valid duration, the
   command fails before the backup starts.
-* Fails before it writes anything when a `file://` destination directory
-  does not exist, or when the local index holds snapshots and the
-  destination has no `vaultik-destination.txt` (see
-  [remote storage layout](#remote-storage-layout))
 
 **`snapshot list`**: Show every snapshot known to this host — the union
 of the local index and the backup destination store — with timestamps
 and three sizes per snapshot (compressed remote size; total
 uncompressed chunk size; size of the chunks that snapshot stored that
-were not stored before, recorded when its backup ran).
+were not stored before). Both chunk sizes are recorded when the
+snapshot's backup runs.
 
 Listing the destination store does **not** require the age secret key,
 so it works in vaultik's intended configuration, where the backed-up
@@ -325,10 +318,7 @@ invocation that reconciles them.
 
 If the destination store cannot be listed (unmounted volume,
 permission denied, network down), the command warns, falls back to the
-local index alone, and still exits zero. It does the same when the
+local index alone, and still exits zero.
-local index holds snapshots and the destination has no
-`vaultik-destination.txt`, as when a volume mounted at the destination
-is unplugged and leaves its empty mount point behind.
 * `--json`: Output in JSON format. Each entry carries `locally_tracked`
   (whether the snapshot is in the local index), `remote_key` (the full
   64-character storage key), and `remote_present` (whether it was seen
@@ -349,7 +339,9 @@ is unplugged and leaves its empty mount point behind.
 
 **`snapshot purge`**: Remove old snapshots based on criteria. Retention is
 per-snapshot-name (`--keep-latest` keeps the latest of each name, not the
-latest globally).
+latest globally). If a snapshot cannot be removed from the local index, the
+command stops there, leaves that snapshot's metadata on the destination store
+and exits non-zero; `snapshot create --prune` fails the same way.
 * `--keep-latest`: Keep only the most recent snapshot of each name
 * `--older-than <duration>`: Remove snapshots older than duration (e.g. `30d`,
   `4w`, `6mo`, `1y`; `m` is minutes, `mo` is months)
@@ -366,13 +358,11 @@ prune` invocation to run as a follow-up. An ID that names no snapshot in
 the local index or on the destination store is an error; with
 `--local-only`, the snapshot must be in the local index. Local row
 cleanup (files, chunks, blobs the snapshot was the last referrer for)
-runs automatically. If the destination store is unreachable, or the
+runs automatically. If the destination store is unreachable, the local-DB
-local index holds snapshots and the destination has no
+removal still completes and a warning is emitted; run `vaultik snapshot
-`vaultik-destination.txt`, the local-DB removal still completes and a
+remove <snapshot-id>` again once the store is reachable to remove the
-warning is emitted; run `vaultik snapshot remove <snapshot-id>` again
+snapshot's metadata from it (`vaultik prune` does not). To wipe everything
-once the store is reachable to remove the snapshot's metadata from it
+on the destination in one go, use `vaultik remote nuke --force`.
-(`vaultik prune` does not). To wipe everything on the destination in one
-go, use `vaultik remote nuke --force`.
 * `--local-only`: Skip remote cleanup; only touch the local index
 * `--dry-run`: Show what would be deleted without deleting
 * `--force`: Skip confirmation prompt
@@ -388,7 +378,9 @@ go, use `vaultik remote nuke --force`.
 * Optional path arguments to restore specific files/directories (default: all)
 * Preserves file permissions, timestamps, ownership (ownership requires root),
   symlinks, and empty directories
-* `--verify`: After restoring, verify every file's chunk hashes match
+* `--verify`: After restoring, verify every restored file's chunk hashes
+  match. A file skipped under `--skip-errors` is reported as failed to
+  restore and is not verified.
 
 **`prune`**: Tidy up everything that isn't needed. Runs three passes:
 (1) reconcile the local index against the destination store — any
@@ -399,12 +391,8 @@ manifest on the destination store to compute the still-referenced blob
 set and delete any blob not in that set. Step (3) reads all remote
 manifests — network cost scales with the number of snapshots. `snapshot
 create --prune` runs the same cleanup automatically; this is the
-manual entry point for the same work. If the destination store cannot
+manual entry point for the same work. If a blob cannot be deleted, the
-be listed, or the local index holds snapshots and the destination has
+command (and `snapshot create --prune`) exits non-zero.
-no `vaultik-destination.txt` (an unplugged volume's empty mount point),
-prune fails and deletes nothing. `snapshot purge` does the same. If a
-blob cannot be deleted, the command (and `snapshot create --prune`)
-exits non-zero.
 * `--force`: Skip confirmation prompt
 * `--json`: Output stats as JSON. Also skips the confirmation prompt, as
   `--force` does. A blob that cannot be deleted is counted in
@@ -427,12 +415,11 @@ under `blobs/` whose name is not a blob hash is not counted as a blob,
 since `prune` never deletes it.
 * `--json`: Output as JSON
 
-**`remote nuke`**: Delete every snapshot's metadata, every blob and
+**`remote nuke`**: Delete every snapshot's metadata and every blob from the
-`vaultik-destination.txt` from the backup destination store, leaving the
+backup destination store, leaving the bucket prefix empty. Destructive and
-bucket prefix empty. Destructive and irreversible. This is the single
+irreversible. This is the single supported way to wipe the entire
-supported way to wipe the entire destination store. If anything cannot
+destination store. If anything cannot be deleted, the command exits
-be deleted, the command exits non-zero; running it again deletes what is
+non-zero; running it again deletes what is left.
-left.
 * `--force`: Required to confirm destruction.
 
 **`database delete`**: Delete the local SQLite state database file
@@ -457,12 +444,7 @@ object store. Credentials are read from `s3.access_key_id` and
 a local or mounted filesystem. Useful for testing or backing up to a NAS. The
 path must be absolute; a relative one is refused when the config loads.
 Percent-escapes in the path are decoded, so `my%20stick` and `my stick` name
-the same directory. The directory must exist before the first backup: vaultik
+the same directory.
-never creates it. A directory on a removable volume is gone while the volume is
-not mounted, so a backup then fails instead of writing to the disk under the
-mount point. The mount point itself stays behind when the volume is unplugged:
-there only `vaultik-destination.txt` stops such a backup, and only while the
-local index holds snapshots.
 
 **Rclone** (`rclone://remote/path`): Uses rclone's 70+ supported cloud
 providers. Requires rclone to be configured separately (`rclone config`).
@@ -493,7 +475,6 @@ For an implementation-level view of the internals — the data model, the
 
 ```
 <bucket>/<prefix>/
-├── vaultik-destination.txt     # Marker written by every backup
 ├── blobs/
 │   └── <aa>/<bb>/<full_blob_hash>
 └── metadata/
@@ -502,15 +483,6 @@ For an implementation-level view of the internals — the data model, the
         └── manifest.json.zst   # Unencrypted blob list (for pruning)
 ```
 
-* `vaultik-destination.txt` holds one fixed line of text, with no host
-  name, path or time. While the local index holds snapshots, a
-  destination without it is treated as not present: `snapshot create`
-  refuses to write to it, `prune` and `snapshot purge` fail, and
-  `snapshot list` and `snapshot remove` warn, as for a destination that
-  cannot be listed. This keeps an unplugged volume's empty mount point
-  from being taken for a destination whose snapshots are all gone. Mount
-  the volume if it is removable; if the destination was emptied on
-  purpose, run `vaultik database delete` and back up again.
 * Blobs are two-level directory sharded using the first 4 hex chars of the blob hash
 * `db.zst.age` is a binary SQLite database (zstd compressed, age encrypted)
   containing all file metadata, chunk mappings, and relationships for the snapshot

cmd/vaultik/dockermoddownload_test.go

@@ -0,0 +1,45 @@
+package main_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestDockerfileBoundsEveryModuleDownload fails unless every
+// `go mod download` in the Dockerfile runs under a time limit, is tried
+// a fixed number of times, and then fails the build with a message that
+// names the module download (issue #351). Like the version tests, this
+// parses the Dockerfile; that a stalled download really is cut off and
+// retried was checked by hand.
+func TestDockerfileBoundsEveryModuleDownload(t *testing.T) {
+	t.Parallel()
+
+	var downloads []string
+
+	for _, instruction := range instructions(t, productDockerfile) {
+		if strings.Contains(instruction, "go mod download") {
+			downloads = append(downloads, instruction)
+		}
+	}
+
+	require.NotEmpty(t, downloads, "%s must download modules",
+		productDockerfile)
+
+	for _, download := range downloads {
+		assert.Contains(t, download, "timeout 300 go mod download",
+			"%s: a module download must have a time limit: %s",
+			productDockerfile, download)
+		assert.Contains(t, download, "for attempt in 1 2 3",
+			"%s: a module download must be retried: %s",
+			productDockerfile, download)
+		assert.Contains(t, download, "module download failed",
+			"%s: a module download that never succeeds must say so: %s",
+			productDockerfile, download)
+		assert.True(t, strings.HasSuffix(download, "exit 1"),
+			"%s: a module download that never succeeds must fail the"+
+				" build: %s", productDockerfile, download)
+	}
+}

docs/DATAMODEL.md

@@ -122,6 +122,7 @@ Tracks backup snapshots.
 - `new_chunk_size` (INTEGER) - Total size of those chunks before compression; `snapshot list` shows it as NEW CHUNK SIZE
 - `blob_count` (INTEGER) - Number of blobs this snapshot created
 - `total_size` (INTEGER) - Total size of all files
+- `uncompressed_chunk_size` (INTEGER) - Total size before compression of the distinct chunks the snapshot's files reference, recorded when its backup ran; `snapshot list` shows it as UNCOMPRESSED SIZE
 - `blob_size` (INTEGER) - Total compressed size of all referenced blobs
 - `blob_uncompressed_size` (INTEGER) - Total uncompressed size of all referenced blobs
 - `compression_ratio` (REAL) - Compression ratio achieved

docs/REPOSTRUCTURE.md

@@ -4,7 +4,7 @@ This document describes the structure and organization of data stored in the S3
 
 ## Overview
 
-Vaultik stores all backup data in an S3-compatible object store. The repository consists of two main components, plus a marker file:
+Vaultik stores all backup data in an S3-compatible object store. The repository consists of two main components:
 1. **Blobs** - The actual backup data (content-addressed, encrypted)
 2. **Metadata** - Snapshot information and manifests (partially encrypted)
 
@@ -12,7 +12,6 @@ Vaultik stores all backup data in an S3-compatible object store. The repository
 
 ```
 <bucket>/<prefix>/
-├── vaultik-destination.txt
 ├── blobs/
 │   └── <hash[0:2]>/
 │       └── <hash[2:4]>/
@@ -25,10 +24,6 @@ Vaultik stores all backup data in an S3-compatible object store. The repository
 
 The metadata subdirectory is named with the **remote key**, a one-way hash of the snapshot ID, not with the human-readable snapshot ID itself. See [Remote Key Derivation](#remote-key-derivation).
 
-## Marker File (`vaultik-destination.txt`)
-
-Every backup writes this file at the root before it uploads anything. It holds one fixed line of plain text and names no host, path or time. While the local index holds snapshots, a destination without it is treated as not present: `snapshot create` refuses to write to it, and `prune`, `snapshot purge`, `snapshot remove` and `snapshot list` behave as for a destination that cannot be listed. An unplugged volume leaves an empty directory at its mount point, and without the marker that directory would read as a destination whose snapshots are all gone. `remote nuke` deletes the marker last.
-
 ## Blobs Directory (`blobs/`)
 
 ### Structure

internal/cli/entry_prune_json_test.go

@@ -101,8 +101,7 @@ func TestEntryPruneJSONStdoutIsExactlyOneDocument(t *testing.T) {
 // writeHermeticPruneConfig builds a config over a temp directory with an
 // empty destination directory and, if seedStale is set, creates the
 // index database up front with one snapshot record that has no
-// counterpart on the destination store, and gives the destination the
+// counterpart on the destination store. Returns the config path.
-// marker a backup writes. Returns the config path.
 func writeHermeticPruneConfig(t *testing.T, seedStale bool) string {
 	t.Helper()
 
@@ -132,11 +131,6 @@ func writeHermeticPruneConfig(t *testing.T, seedStale bool) string {
 
 	if seedStale {
 		seedStaleSnapshotRecord(t, indexPath)
-
-		// While the local index holds a snapshot, prune fails on a
-		// destination without the marker a backup writes.
-		require.NoError(t, os.WriteFile(
-			filepath.Join(storeDir, "vaultik-destination.txt"), nil, 0o600))
 	}
 
 	return configPath

internal/cli/entry_snapshot_purge_test.go

@@ -0,0 +1,90 @@
+package cli //nolint:testpackage // shares runEntry and the hermetic config helpers
+
+import (
+	"context"
+	"database/sql"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/database"
+	"sneak.berlin/go/vaultik/internal/snapshot"
+	"sneak.berlin/go/vaultik/internal/types"
+)
+
+// The `snapshot purge` command word and flags used below.
+const (
+	cmdPurge       = "purge"
+	flagKeepLatest = "--keep-latest"
+	flagForce      = "--force"
+)
+
+// TestEntrySnapshotPurgeKeepsMetadataWhenLocalIndexDeleteFails makes
+// removing a snapshot from the local index fail and checks that
+// `snapshot purge` exits non-zero and leaves that snapshot's metadata on
+// the destination store. It used to log the error, delete the metadata
+// anyway and exit 0.
+//
+//nolint:paralleltest // replaces os.Args, os.Stdout, os.Stderr and the xdg globals
+func TestEntrySnapshotPurgeKeepsMetadataWhenLocalIndexDeleteFails(t *testing.T) {
+	ctx := context.Background()
+	configPath := writeHermeticPruneConfig(t, false)
+
+	// writeHermeticPruneConfig puts the index and the store directory
+	// beside the config file.
+	dir := filepath.Dir(configPath)
+
+	// Two snapshots of the same name: --keep-latest purges the older.
+	olderStart := time.Date(2026, 5, 1, 9, 0, 0, 0, time.UTC)
+	newerStart := olderStart.Add(time.Hour)
+	olderID := "test-host_test_" + olderStart.Format(time.RFC3339)
+	newerID := "test-host_test_" + newerStart.Format(time.RFC3339)
+
+	db, err := database.New(ctx, filepath.Join(dir, "index.sqlite"))
+	require.NoError(t, err)
+
+	repos := database.NewRepositories(db)
+
+	manifestPaths := make(map[string]string)
+
+	for id, startedAt := range map[string]time.Time{
+		olderID: olderStart,
+		newerID: newerStart,
+	} {
+		completedAt := startedAt.Add(time.Minute)
+		snap := &database.Snapshot{
+			ID:             types.SnapshotID(id),
+			Hostname:       "test-host",
+			VaultikVersion: "test",
+			StartedAt:      startedAt,
+			CompletedAt:    &completedAt,
+		}
+
+		err = repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
+			return repos.Snapshots.Create(ctx, tx, snap)
+		})
+		require.NoError(t, err)
+
+		manifestPaths[id] = filepath.Join(dir, "store", "metadata",
+			snapshot.RemoteSnapshotKey(id), "manifest.json.zst")
+		require.NoError(t, os.MkdirAll(filepath.Dir(manifestPaths[id]), 0o750))
+		require.NoError(t, os.WriteFile(manifestPaths[id], []byte("stub"), 0o600))
+	}
+
+	_, err = db.Conn().ExecContext(ctx, `
+		CREATE TRIGGER refuse_snapshot_delete BEFORE DELETE ON snapshots
+		BEGIN SELECT RAISE(ABORT, 'simulated index error'); END`)
+	require.NoError(t, err)
+	require.NoError(t, db.Close())
+
+	code, _, stderr := runEntry(t,
+		flagConfig, configPath, cmdSnapshot, cmdPurge, flagKeepLatest, flagForce)
+
+	assert.Equal(t, 1, code)
+	assert.Contains(t, stderr, "simulated index error")
+	assert.FileExists(t, manifestPaths[olderID],
+		"a snapshot still in the local index keeps its metadata")
+}

internal/database/schema/001.sql

@@ -89,6 +89,7 @@ CREATE TABLE IF NOT EXISTS snapshots (
     new_chunk_size INTEGER NOT NULL DEFAULT 0,
     blob_count INTEGER NOT NULL DEFAULT 0,
     total_size INTEGER NOT NULL DEFAULT 0,
+    uncompressed_chunk_size INTEGER NOT NULL DEFAULT 0,
     blob_size INTEGER NOT NULL DEFAULT 0,
     blob_uncompressed_size INTEGER NOT NULL DEFAULT 0,
     compression_ratio REAL NOT NULL DEFAULT 1.0,

internal/database/snapshots.go

@@ -120,7 +120,11 @@ func (r *SnapshotRepository) UpdateCounts(
 	return nil
 }
 
-// UpdateExtendedStats updates extended statistics for a snapshot
+// UpdateExtendedStats updates extended statistics for a snapshot. It also
+// records the total plaintext size of the distinct chunks the snapshot's
+// files reference. Only the snapshot's own backup can take that total: a
+// file's row is shared by every snapshot that lists it, and a later
+// backup of a changed file rewrites the row with the new chunks.
 func (r *SnapshotRepository) UpdateExtendedStats(
 	ctx context.Context,
 	tx *sql.Tx,
@@ -145,7 +149,17 @@ func (r *SnapshotRepository) UpdateExtendedStats(
 		    compression_level = ?,
 		    upload_bytes = ?,
 		    upload_duration_ms = ?,
-		    new_chunk_size = ?
+		    new_chunk_size = ?,
+		    uncompressed_chunk_size = (
+		        SELECT COALESCE(SUM(c.size), 0)
+		        FROM (
+		            SELECT DISTINCT fc.chunk_hash
+		            FROM snapshot_files sf
+		            JOIN file_chunks fc ON sf.file_id = fc.file_id
+		            WHERE sf.snapshot_id = snapshots.id
+		        ) sc
+		        JOIN chunks c ON sc.chunk_hash = c.chunk_hash
+		    )
 		WHERE id = ?
 	`
 
@@ -555,30 +569,22 @@ func (r *SnapshotRepository) GetSnapshotBlobSizes(
 	return compressed, uncompressed, nil
 }
 
-// GetSnapshotUncompressedChunkSize returns the sum of plaintext sizes of all unique
+// GetSnapshotUncompressedChunkSize returns the total plaintext size of the
-// chunks referenced by a snapshot (via snapshot_files → file_chunks → chunks).
+// distinct chunks the snapshot's files reference, as the snapshot's backup
+// recorded it (see UpdateExtendedStats).
 func (r *SnapshotRepository) GetSnapshotUncompressedChunkSize(
 	ctx context.Context, snapshotID string,
 ) (int64, error) {
-	query := `
+	query := `SELECT uncompressed_chunk_size FROM snapshots WHERE id = ?`
-		SELECT COALESCE(SUM(c.size), 0)
-		FROM (
-			SELECT DISTINCT fc.chunk_hash
-			FROM snapshot_files sf
-			JOIN file_chunks fc ON sf.file_id = fc.file_id
-			WHERE sf.snapshot_id = ?
-		) sc
-		JOIN chunks c ON sc.chunk_hash = c.chunk_hash
-	`
 
-	var totalSize int64
+	var uncompressedChunkSize int64
 
-	err := r.db.conn.QueryRowContext(ctx, query, snapshotID).Scan(&totalSize)
+	err := r.db.conn.QueryRowContext(ctx, query, snapshotID).Scan(&uncompressedChunkSize)
 	if err != nil {
 		return 0, fmt.Errorf("querying uncompressed chunk size: %w", err)
 	}
 
-	return totalSize, nil
+	return uncompressedChunkSize, nil
 }
 
 // GetSnapshotNewChunkSize returns the total plaintext size of the chunks the

internal/storage/file.go

@@ -21,13 +21,9 @@ type FileStorer struct {
 // NewFileStorer creates a new filesystem storage backend.
 //
 // Construction is intentionally cheap and does not touch the filesystem.
-// The backend never creates basePath: the user does, so that when
+// The basePath is recorded; the directory is created lazily on first
-// basePath is a directory on an unplugged volume, a write fails instead
+// write. Write operations (Put/PutWithProgress) call MkdirAll for the
-// of landing on the disk under the mount point. This does not hold when
+// per-blob parent directory, which also covers basePath on first use.
-// basePath is the mount point itself, which stays behind when its volume
-// is unplugged.
-// Put and PutWithProgress fail on a missing basePath and create the
-// directories below it as needed.
 // Get and Stat report a key under a missing basePath as ErrNotFound.
 // List and ListStream fail on a missing basePath, because listing it as
 // an empty store would make `prune` drop every local snapshot record.
@@ -301,19 +297,7 @@ func (f *FileStorer) writeAtomic(
 	path := f.fullPath(key)
 	dir := filepath.Dir(path)
 
-	// Checked on every write, so a destination that disappears part-way
+	err := f.fs.MkdirAll(dir, storageDirPerm)
-	// through a backup fails it rather than being recreated by MkdirAll.
-	_, err := f.fs.Stat(f.basePath)
-	if os.IsNotExist(err) {
-		return fmt.Errorf("destination directory does not exist; "+
-			"create it, or mount the volume it is on: %w", err)
-	}
-
-	if err != nil {
-		return fmt.Errorf("checking destination directory: %w", err)
-	}
-
-	err = f.fs.MkdirAll(dir, storageDirPerm)
 	if err != nil {
 		return fmt.Errorf("creating directories: %w", err)
 	}

internal/storage/file_backend_test.go

@@ -4,9 +4,7 @@ import (
 	"context"
 	"errors"
 	"io/fs"
-	"os"
 	"path/filepath"
-	"strings"
 	"testing"
 
 	"sneak.berlin/go/vaultik/internal/storage"
@@ -62,43 +60,3 @@ func TestFileStorerListMissingDestination(t *testing.T) {
 		t.Errorf("ListStream error = %v, want a not-exist error", streamErr)
 	}
 }
-
-// TestFileStorerPutMissingDestination checks that a write fails when the
-// destination directory has gone, even after earlier writes to it
-// succeeded, and that it does not create the directory again.
-func TestFileStorerPutMissingDestination(t *testing.T) {
-	t.Parallel()
-
-	ctx := context.Background()
-	base := filepath.Join(t.TempDir(), "usbstick")
-
-	err := os.Mkdir(base, 0o750)
-	if err != nil {
-		t.Fatalf("Mkdir: %v", err)
-	}
-
-	s, err := storage.NewFileStorer(base)
-	if err != nil {
-		t.Fatalf("NewFileStorer: %v", err)
-	}
-
-	err = s.Put(ctx, "blobs/aa/bb/first", strings.NewReader("first"))
-	if err != nil {
-		t.Fatalf("first Put: %v", err)
-	}
-
-	err = os.Rename(base, base+"-unplugged")
-	if err != nil {
-		t.Fatalf("Rename: %v", err)
-	}
-
-	err = s.Put(ctx, "blobs/aa/bb/second", strings.NewReader("second"))
-	if !errors.Is(err, fs.ErrNotExist) {
-		t.Errorf("Put = %v, want a not-exist error", err)
-	}
-
-	_, err = os.Stat(base)
-	if !errors.Is(err, fs.ErrNotExist) {
-		t.Errorf("Put created the destination directory again (Stat = %v)", err)
-	}
-}

internal/storage/storer.go

@@ -41,8 +41,7 @@ type Info struct {
 // directory for filesystem).
 type Storer interface {
 	// Put stores data at the specified key.
-	// The filesystem backend fails when its destination directory does
+	// Parent directories are created automatically for filesystem backends.
-	// not exist, and creates the directories below it as needed.
 	Put(ctx context.Context, key string, data io.Reader) error
 
 	// PutWithProgress stores data with progress reporting.

internal/vaultik/changed_file_restore_test.go

@@ -137,7 +137,7 @@ func TestBackupAfterRemovingNewestSnapshotRestoresChangedFile(t *testing.T) {
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 	changedPath := filepath.Join(dataDir, "appended.bin")
@@ -184,7 +184,7 @@ func TestBackupAfterInterruptedRunRestoresChangedFile(t *testing.T) {
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 	changedPath := filepath.Join(dataDir, "appended.bin")

internal/vaultik/deep_verify_test.go

@@ -1,7 +1,9 @@
 package vaultik_test
 
 import (
+	"bytes"
 	"context"
+	"crypto/rand"
 	"io"
 	"os"
 	"path/filepath"
@@ -9,7 +11,9 @@ import (
 
 	"github.com/spf13/afero"
 	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/config"
 	"sneak.berlin/go/vaultik/internal/log"
+	"sneak.berlin/go/vaultik/internal/storage"
 	"sneak.berlin/go/vaultik/internal/ui"
 	"sneak.berlin/go/vaultik/internal/vaultik"
 )
@@ -30,7 +34,7 @@ func TestDeepVerifyAcceptsHealthyAndRejectsCorruptBlob(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	chunkSize := int64(64 * 1024)
@@ -77,6 +81,174 @@ func TestDeepVerifyAcceptsHealthyAndRejectsCorruptBlob(t *testing.T) {
 		"deep verify should fail on a corrupted blob")
 }
 
+// TestDeepVerifyJSONCountsBlobs checks the verified and missing counts
+// that deep verify reports under --json: on a healthy snapshot, with a
+// damaged blob, and with missing blobs. Deep verify stops at the first
+// damaged blob, so the blobs read before it are the ones verified; when
+// blobs are missing it reads no blob contents, but counts every missing
+// blob.
+func TestDeepVerifyJSONCountsBlobs(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	fs := afero.NewOsFs()
+	ctx := context.Background()
+	storeDir := filepath.Join(t.TempDir(), "remote")
+
+	cfg, storer, snapshotID, keys := backUpSeveralBlobs(ctx, t, storeDir)
+
+	healthy, err := deepVerifyJSON(ctx, t, cfg, storer, snapshotID)
+	require.NoError(t, err)
+	require.Equal(t, "ok", healthy.Status)
+	require.Len(t, keys, healthy.BlobCount)
+	require.Equal(t, healthy.BlobCount, healthy.Verified)
+	require.Zero(t, healthy.Missing)
+
+	// Damage the last blob read, keeping its length, so every blob before
+	// it is read and passes first.
+	lastPath := filepath.Join(storeDir, keys[len(keys)-1])
+	blob, err := afero.ReadFile(fs, lastPath)
+	require.NoError(t, err)
+
+	blob[len(blob)/2] ^= 0xff
+	require.NoError(t, afero.WriteFile(fs, lastPath, blob, 0o600))
+
+	got, err := deepVerifyJSON(ctx, t, cfg, storer, snapshotID)
+	require.Error(t, err)
+	require.Equal(t, "failed", got.Status)
+	require.Equal(t, healthy.BlobCount-1, got.Verified)
+	require.Zero(t, got.Missing)
+
+	// Delete the first blob and the damaged last one: both must be
+	// counted as missing, not only the first one found.
+	var deletedSize int64
+
+	for _, key := range []string{keys[0], keys[len(keys)-1]} {
+		info, statErr := storer.Stat(ctx, key)
+		require.NoError(t, statErr)
+
+		deletedSize += info.Size
+
+		require.NoError(t, storer.Delete(ctx, key))
+	}
+
+	got, err = deepVerifyJSON(ctx, t, cfg, storer, snapshotID)
+	require.Error(t, err)
+	require.Equal(t, "failed", got.Status)
+	require.Equal(t, 2, got.Missing)
+	require.Equal(t, deletedSize, got.MissingSize)
+	require.Zero(t, got.Verified)
+}
+
+// TestDeepVerifyJSONCountsWrongSizeBlob checks that under --deep --json a
+// blob of the wrong size is counted in mismatched and fails the run, and
+// that the check goes on past it to count a missing blob after it.
+func TestDeepVerifyJSONCountsWrongSizeBlob(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	fs := afero.NewOsFs()
+	ctx := context.Background()
+	storeDir := filepath.Join(t.TempDir(), "remote")
+
+	cfg, storer, snapshotID, keys := backUpSeveralBlobs(ctx, t, storeDir)
+
+	// Make the first blob checked longer, and delete the last one.
+	firstPath := filepath.Join(storeDir, keys[0])
+	blob, err := afero.ReadFile(fs, firstPath)
+	require.NoError(t, err)
+
+	blob = append(blob, []byte("extra")...)
+	require.NoError(t, afero.WriteFile(fs, firstPath, blob, 0o600))
+	require.NoError(t, storer.Delete(ctx, keys[len(keys)-1]))
+
+	got, err := deepVerifyJSON(ctx, t, cfg, storer, snapshotID)
+	require.Error(t, err)
+	require.Equal(t, "failed", got.Status)
+	require.Equal(t, 1, got.Mismatched)
+	require.Equal(t, 1, got.Missing)
+	require.Zero(t, got.Verified)
+}
+
+// TestDeepVerifyStopsOnBlobThatCannotBeChecked checks that a blob that is
+// present in storage but cannot be checked is not counted as missing:
+// deep verify stops and fails with the storage error.
+func TestDeepVerifyStopsOnBlobThatCannotBeChecked(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	ctx := context.Background()
+	storeDir := filepath.Join(t.TempDir(), "remote")
+
+	cfg, storer, snapshotID, keys := backUpSeveralBlobs(ctx, t, storeDir)
+	failing := statFailingStorer{Storer: storer, failKeys: []string{keys[0]}}
+
+	got, err := deepVerifyJSON(ctx, t, cfg, failing, snapshotID)
+	require.Error(t, err)
+	require.Equal(t, "failed", got.Status)
+	require.Zero(t, got.Missing)
+	require.Contains(t, got.ErrorMessage, errStatDenied.Error())
+}
+
+// backUpSeveralBlobs backs up random data, which does not compress or
+// deduplicate, so it fills at least three blobs in a store on disk at
+// storeDir. It returns the blobs' storage keys sorted, which is hash
+// order, the order deep verify reads them in.
+func backUpSeveralBlobs(
+	ctx context.Context, t *testing.T, storeDir string,
+) (*config.Config, *storage.FileStorer, string, []string) {
+	t.Helper()
+
+	fs := afero.NewOsFs()
+	tempDir := t.TempDir()
+	dataDir := filepath.Join(tempDir, "source")
+	dbPath := filepath.Join(tempDir, "index.sqlite")
+
+	chunkSize := int64(32 * 1024)
+	maxBlobSize := int64(128 * 1024)
+
+	data := make([]byte, maxBlobSize*4)
+	_, err := rand.Read(data)
+	require.NoError(t, err)
+	require.NoError(t, fs.MkdirAll(dataDir, 0o755))
+	require.NoError(t, afero.WriteFile(fs,
+		filepath.Join(dataDir, "data.bin"), data, 0o644))
+
+	cfg, storer, snapshotID := runFileStorageBackup(
+		ctx, t, fs, dataDir, storeDir, dbPath, chunkSize, maxBlobSize)
+
+	keys := storedBlobKeys(t, storeDir)
+	require.GreaterOrEqual(t, len(keys), 3)
+
+	return cfg, storer, snapshotID, keys
+}
+
+// deepVerifyJSON runs deep verify with --json on snapshotID and returns
+// the decoded result and the error RunDeepVerify returned.
+func deepVerifyJSON(
+	ctx context.Context, t *testing.T,
+	cfg *config.Config, storer storage.Storer, snapshotID string,
+) (vaultik.VerifyResult, error) {
+	t.Helper()
+
+	var out bytes.Buffer
+
+	v := &vaultik.Vaultik{
+		Config:  cfg,
+		Storage: storer,
+		Fs:      afero.NewOsFs(),
+		Stdout:  &out,
+		Stderr:  io.Discard,
+		UI:      ui.NewWithColor(io.Discard, false),
+	}
+	v.SetContext(ctx)
+
+	err := v.RunDeepVerify(snapshotID,
+		&vaultik.VerifyOptions{Deep: true, JSON: true})
+
+	return decodeVerifyResult(t, out.Bytes()), err
+}
+
 // corruptOneBlob flips a middle byte of the first blob file found under
 // blobsDir, leaving the file length unchanged.
 func corruptOneBlob(t *testing.T, fs afero.Fs, blobsDir string) {

internal/vaultik/destination_marker.go

@@ -1,74 +0,0 @@
-package vaultik
-
-import (
-	"errors"
-	"fmt"
-	"strings"
-
-	"sneak.berlin/go/vaultik/internal/storage"
-)
-
-// destinationMarkerKey is the object every backup writes at the root of
-// the backup destination store. While the local index holds a snapshot,
-// a destination without it is treated as not present: an unplugged
-// volume leaves an empty directory at its mount point, which would
-// otherwise read as a store whose snapshots are all gone.
-const destinationMarkerKey = "vaultik-destination.txt"
-
-// destinationMarkerText is the whole content of the marker. It names no
-// host, path or time.
-const destinationMarkerText = "This is a vaultik backup destination store.\n"
-
-// errDestinationNotPresent is returned when the local index holds a
-// snapshot and the backup destination store has no marker.
-var errDestinationNotPresent = errors.New("backup destination store is not present")
-
-// checkDestinationMarker returns errDestinationNotPresent when the local
-// index holds a snapshot and the backup destination store has no marker.
-// With no snapshot in the local index, as on a first backup or on
-// another machine, there is nothing to check.
-func (v *Vaultik) checkDestinationMarker() error {
-	ids, err := v.localSnapshotIDs()
-	if err != nil {
-		return fmt.Errorf("listing local snapshots: %w", err)
-	}
-
-	if len(ids) == 0 {
-		return nil
-	}
-
-	_, err = v.Storage.Stat(v.ctx, destinationMarkerKey)
-	if errors.Is(err, storage.ErrNotFound) {
-		return fmt.Errorf("%w: %s has no %s, but the local index holds "+
-			"snapshots stored there; mount the volume if it is removable, "+
-			"or if the destination was emptied on purpose, run "+
-			"'vaultik database delete' and back up again",
-			errDestinationNotPresent, v.Storage.Info().Location,
-			destinationMarkerKey)
-	}
-
-	if err != nil {
-		return fmt.Errorf("checking for %s: %w", destinationMarkerKey, err)
-	}
-
-	return nil
-}
-
-// markDestination checks the backup destination store with
-// checkDestinationMarker and then writes the marker, so a first backup
-// marks its destination and a later one writes the same text again.
-func (v *Vaultik) markDestination() error {
-	err := v.checkDestinationMarker()
-	if err != nil {
-		return err
-	}
-
-	err = v.Storage.Put(v.ctx, destinationMarkerKey,
-		strings.NewReader(destinationMarkerText))
-	if err != nil {
-		return fmt.Errorf("writing %s to the backup destination store: %w",
-			destinationMarkerKey, err)
-	}
-
-	return nil
-}

internal/vaultik/destination_marker_test.go

@@ -1,184 +0,0 @@
-package vaultik_test
-
-import (
-	"bytes"
-	"context"
-	"os"
-	"path/filepath"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"sneak.berlin/go/vaultik/internal/database"
-	"sneak.berlin/go/vaultik/internal/log"
-	"sneak.berlin/go/vaultik/internal/vaultik"
-)
-
-// These tests cover https://git.eeqj.de/sneak/vaultik/issues/239: a
-// file:// destination at a volume's mount point leaves an empty directory
-// behind when the volume is unplugged. While the local index holds
-// snapshots, a destination without vaultik-destination.txt is not present,
-// so no command may write to it or conclude from it that the local
-// snapshots are gone.
-
-// markerFile is the name of the file a backup writes at the root of the
-// destination.
-const markerFile = "vaultik-destination.txt"
-
-// backUpThenUnplugMountPoint backs up to a file:// destination, then
-// moves the destination directory away and leaves an empty directory in
-// its place, as unplugging a volume mounted there would. It returns the
-// path of that empty directory.
-func backUpThenUnplugMountPoint(
-	ctx context.Context, t *testing.T,
-) (*vaultik.Vaultik, *database.Repositories, *bytes.Buffer, string) {
-	t.Helper()
-
-	storeDir := filepath.Join(t.TempDir(), "mnt")
-	v, repos, out := backUpToFileDestination(ctx, t, storeDir)
-
-	require.NoError(t, os.Rename(storeDir, storeDir+"-unplugged"))
-	require.NoError(t, os.Mkdir(storeDir, 0o750))
-
-	return v, repos, out, storeDir
-}
-
-// assertUntouched checks that the local index still holds its one
-// snapshot and that nothing was written to the empty mount point.
-func assertUntouched(
-	ctx context.Context, t *testing.T,
-	repos *database.Repositories, storeDir string,
-) {
-	t.Helper()
-
-	snapshots, err := repos.Snapshots.ListRecent(ctx, listRecentTestLimit)
-	require.NoError(t, err)
-	assert.Len(t, snapshots, 1, "no local snapshot record may be deleted")
-
-	entries, err := os.ReadDir(storeDir)
-	require.NoError(t, err)
-	assert.Empty(t, entries, "nothing may be written to the empty mount point")
-}
-
-// TestFirstBackupWritesMarker checks that a backup writes the marker
-// file at the root of the destination.
-func TestFirstBackupWritesMarker(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	storeDir := t.TempDir()
-	backUpToFileDestination(context.Background(), t, storeDir)
-
-	assert.FileExists(t, filepath.Join(storeDir, markerFile))
-}
-
-// TestBackupRefusesDestinationWithoutMarker checks that snapshot create
-// --prune writes nothing and drops no local snapshot record when the
-// destination has no marker.
-func TestBackupRefusesDestinationWithoutMarker(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	v, repos, _, storeDir := backUpThenUnplugMountPoint(ctx, t)
-
-	err := v.CreateSnapshot(&vaultik.SnapshotCreateOptions{
-		Cron:  true,
-		Prune: true,
-	})
-	require.ErrorContains(t, err, markerFile)
-
-	assertUntouched(ctx, t, repos, storeDir)
-}
-
-// TestPruneRefusesDestinationWithoutMarker checks that prune fails and
-// deletes no local snapshot record when the destination has no marker.
-func TestPruneRefusesDestinationWithoutMarker(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	v, repos, _, storeDir := backUpThenUnplugMountPoint(ctx, t)
-
-	err := v.Prune(&vaultik.PruneOptions{Force: true})
-	require.ErrorContains(t, err, markerFile)
-
-	assertUntouched(ctx, t, repos, storeDir)
-}
-
-// TestPurgeRefusesDestinationWithoutMarker checks that snapshot purge
-// fails and deletes no local snapshot record when the destination has no
-// marker.
-func TestPurgeRefusesDestinationWithoutMarker(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	v, repos, _, storeDir := backUpThenUnplugMountPoint(ctx, t)
-
-	err := v.PurgeSnapshotsWithOptions(&vaultik.SnapshotPurgeOptions{
-		KeepLatest: true,
-		Force:      true,
-	})
-	require.ErrorContains(t, err, markerFile)
-
-	assertUntouched(ctx, t, repos, storeDir)
-}
-
-// TestRemoveSnapshotWarnsWhenDestinationHasNoMarker checks that snapshot
-// remove warns that the metadata could not be removed from a destination
-// without a marker, instead of reporting that it was.
-func TestRemoveSnapshotWarnsWhenDestinationHasNoMarker(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	v, repos, out, _ := backUpThenUnplugMountPoint(ctx, t)
-
-	result, err := v.RemoveSnapshot(localSnapshotID(ctx, t, repos, "first"),
-		&vaultik.RemoveOptions{Force: true})
-	require.NoError(t, err)
-
-	assert.False(t, result.RemoteRemoved)
-	assert.Contains(t, out.String(),
-		"Could not remove snapshot metadata from remote")
-	assert.Contains(t, out.String(), markerFile)
-	assert.NotContains(t, out.String(),
-		"Removed snapshot metadata from remote storage")
-}
-
-// TestListSnapshotsWarnsWhenDestinationHasNoMarker checks that snapshot
-// list warns and shows the local index alone when the destination has no
-// marker, without reporting the local snapshot as missing from it.
-func TestListSnapshotsWarnsWhenDestinationHasNoMarker(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	v, repos, out, _ := backUpThenUnplugMountPoint(ctx, t)
-	id := localSnapshotID(ctx, t, repos, "first")
-
-	require.NoError(t, v.ListSnapshots(false))
-
-	assert.Contains(t, out.String(), "Could not list backup destination store")
-	assert.Contains(t, out.String(), markerFile)
-	assert.Contains(t, out.String(), id)
-	assert.NotContains(t, out.String(), "not found in backup destination store")
-}
-
-// TestBackupAfterNukeRemoteSucceeds checks that remote nuke leaves the
-// destination ready for a new first backup, which writes the marker
-// again.
-func TestBackupAfterNukeRemoteSucceeds(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	storeDir := t.TempDir()
-	v, _, _ := backUpToFileDestination(context.Background(), t, storeDir)
-
-	require.NoError(t, v.NukeRemote(true))
-	assert.NoFileExists(t, filepath.Join(storeDir, markerFile))
-
-	require.NoError(t, backUp(v, "second"))
-	assert.FileExists(t, filepath.Join(storeDir, markerFile))
-}

internal/vaultik/fault_injection_test.go

@@ -192,7 +192,7 @@ func assertRestoreRejectsDamagedBlob(
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
@@ -238,7 +238,7 @@ func TestDeepVerifyCatchesLyingBackend(t *testing.T) {
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	ctx := context.Background()
@@ -290,7 +290,7 @@ func TestInterruptedBlobUploadRecordsNoUploadedBlob(t *testing.T) {
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	ctx := context.Background()
@@ -298,6 +298,10 @@ func TestInterruptedBlobUploadRecordsNoUploadedBlob(t *testing.T) {
 
 	writeFaultSourceTree(t, fs, dataDir)
 
+	// No upload succeeds, so nothing creates the destination directory.
+	// It must exist for the listing below to show that no blob survived.
+	require.NoError(t, os.Mkdir(storeDir, 0o750))
+
 	inner, err := storage.NewFileStorer(storeDir)
 	require.NoError(t, err)
 
@@ -361,7 +365,7 @@ func TestBackupRetryAfterInterruptedUploadIsRestorable(t *testing.T) {
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
@@ -425,7 +429,7 @@ func TestBackupSurvivesMetadataExportInterruption(t *testing.T) {
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	ctx := context.Background()
@@ -507,7 +511,7 @@ func TestBackupCompletesOnlyAfterMetadataExport(t *testing.T) {
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
@@ -682,7 +686,7 @@ func TestRestoreReportsDiskFull(t *testing.T) {
 	osFS := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 

internal/vaultik/integration_test.go

@@ -771,7 +771,7 @@ func TestEndToEndFileStorage(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
@@ -964,7 +964,7 @@ func TestDedupOnlySnapshotRestores(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 

internal/vaultik/missing_destination_test.go

@@ -24,11 +24,13 @@ import (
 // that is not plugged in, cannot be listed. It is not an empty store, so
 // no command may conclude from it that the local snapshots are gone.
 
-// newFileDestinationVaultik returns a Vaultik that backs up the
+// backUpToFileDestination backs up the snapshot named "first" to a
-// snapshot named "first" to a file:// destination at storeDir.
+// file:// destination at storeDir, which need not exist yet. Everything
-func newFileDestinationVaultik(
+// the returned Vaultik prints after the backup goes to the returned
+// buffer.
+func backUpToFileDestination(
 	ctx context.Context, t *testing.T, storeDir string,
-) (*vaultik.Vaultik, *database.Repositories) {
+) (*vaultik.Vaultik, *database.Repositories, *bytes.Buffer) {
 	t.Helper()
 
 	osFs := afero.NewOsFs()
@@ -47,22 +49,8 @@ func newFileDestinationVaultik(
 
 	repos := database.NewRepositories(db)
 	cfg := changedFileConfig(dataDir, dbPath)
+	v := newBackupVaultik(ctx, cfg, store, repos, db, osFs)
 
-	return newBackupVaultik(ctx, cfg, store, repos, db, osFs), repos
-}
-
-// backUpToFileDestination creates the directory storeDir, as a user must
-// before the first backup, and backs up the snapshot named "first" to a
-// file:// destination there. Everything the returned Vaultik prints
-// after the backup goes to the returned buffer.
-func backUpToFileDestination(
-	ctx context.Context, t *testing.T, storeDir string,
-) (*vaultik.Vaultik, *database.Repositories, *bytes.Buffer) {
-	t.Helper()
-
-	require.NoError(t, os.MkdirAll(storeDir, 0o750))
-
-	v, repos := newFileDestinationVaultik(ctx, t, storeDir)
 	require.NoError(t, backUp(v, "first"))
 
 	out := &bytes.Buffer{}
@@ -87,28 +75,21 @@ func backUpThenUnplug(
 	return v, repos, out
 }
 
-// TestBackupFailsWhenDestinationDirectoryMissing checks that a backup to
+// TestFirstBackupCreatesDestinationDirectory checks that a first backup
-// a file:// destination whose directory does not exist fails before it
+// to a destination directory that does not exist yet creates it, and
-// records a snapshot, and does not create the directory.
+// that the destination can be listed afterwards.
-func TestBackupFailsWhenDestinationDirectoryMissing(t *testing.T) {
+func TestFirstBackupCreatesDestinationDirectory(t *testing.T) {
 	log.Initialize(log.Config{})
 	t.Parallel()
 
 	ctx := context.Background()
-	volume := filepath.Join(t.TempDir(), "volume")
+	storeDir := filepath.Join(t.TempDir(), "volume", "backup")
-	v, repos := newFileDestinationVaultik(ctx, t, filepath.Join(volume, "backup"))
+	v, _, out := backUpToFileDestination(ctx, t, storeDir)
 
-	err := backUp(v, "first")
+	require.NoError(t, v.ListSnapshots(false))
-	require.ErrorIs(t, err, fs.ErrNotExist)
-	require.ErrorContains(t, err, "create it, or mount the volume it is on")
 
-	_, err = os.Stat(volume)
+	assert.NotContains(t, out.String(), "Could not list backup destination store")
-	require.ErrorIs(t, err, fs.ErrNotExist,
+	assert.NotContains(t, out.String(), "not found in backup destination store")
-		"the backup must not create the destination directory")
-
-	snapshots, err := repos.Snapshots.ListRecent(ctx, listRecentTestLimit)
-	require.NoError(t, err)
-	assert.Empty(t, snapshots)
 }
 
 // TestListSnapshotsWarnsWhenDestinationMissing checks that snapshot list

internal/vaultik/new_chunk_size_test.go

@@ -39,7 +39,7 @@ func TestNewChunkSizeOfChangedFileStaysFixed(t *testing.T) {
 
 	appendRandomBytes(t, fs, files, changedPath, appendedFileSize)
 
-	store, err := storage.NewFileStorer(t.TempDir())
+	store, err := storage.NewFileStorer(filepath.Join(tempDir, "remote"))
 	require.NoError(t, err)
 
 	db, err := database.New(ctx, dbPath)

internal/vaultik/prune.go

@@ -37,9 +37,8 @@ const blobKeyParts = 4
 
 // NukeRemote deletes every snapshot's metadata and every blob from remote
 // storage, along with any object an upload cut off part-way left under a
-// temporary `.partial` name, and the destination marker. After this
+// temporary `.partial` name. After this returns successfully the bucket
-// returns successfully the bucket prefix is empty and the next backup
+// prefix is empty and the next backup starts from scratch.
-// starts from scratch.
 //
 // Refuses to run unless force is true. The caller is responsible for
 // confirming with the user.
@@ -94,13 +93,6 @@ func (v *Vaultik) emptyDestinationStore() error {
 		}
 	}
 
-	// Last, once the local snapshot records are gone: the next backup
-	// then has none and writes the marker again.
-	err = v.Storage.Delete(v.ctx, destinationMarkerKey)
-	if err != nil {
-		return fmt.Errorf("deleting %s: %w", destinationMarkerKey, err)
-	}
-
 	return nil
 }
 

internal/vaultik/purge_local_remote_consistency_test.go

@@ -34,9 +34,6 @@ func setupConsistencyTest(
 	repos := database.NewRepositories(db)
 	mockStorage := NewMockStorer()
 
-	// A backup wrote to this destination, so it carries the marker.
-	require.NoError(t, mockStorage.Put(ctx, markerFile, strings.NewReader("")))
-
 	for _, id := range snapshotIDs {
 		parts := strings.Split(id, "_")
 		startedAt, err := time.Parse(time.RFC3339, parts[len(parts)-1])

internal/vaultik/purge_per_name_test.go

@@ -44,9 +44,6 @@ func setupPurgeTest(
 	repos := database.NewRepositories(db)
 	mockStorage := NewMockStorer()
 
-	// A backup wrote to this destination, so it carries the marker.
-	require.NoError(t, mockStorage.Put(ctx, markerFile, strings.NewReader("")))
-
 	// Insert each snapshot into the DB and create remote metadata stubs.
 	// Use timestamps parsed from snapshot IDs for realistic ordering.
 	for _, id := range snapshotIDs {

internal/vaultik/remove_snapshot_test.go

@@ -303,10 +303,6 @@ func TestRemoveSnapshot_DefaultRemovesMetadataNotBlobs(t *testing.T) {
 	addBlob(t, store, blobUnique)
 	addBlob(t, store, blobShared)
 
-	// A backup wrote to this destination, so it carries the marker.
-	require.NoError(t, store.Put(context.Background(), markerFile,
-		bytes.NewReader(nil)))
-
 	tv := vaultik.NewForTesting(store)
 	tv.Repositories = newLocalIndex(t, "snapshot-001", "snapshot-002")
 
@@ -396,12 +392,7 @@ func TestRemoveSnapshot_NoMetadataOnDestination(t *testing.T) {
 	log.Initialize(log.Config{})
 	t.Parallel()
 
-	// A backup wrote to this destination, so it carries the marker.
+	tv := vaultik.NewForTesting(newTestStorer())
-	store := newTestStorer()
-	require.NoError(t, store.Put(context.Background(), markerFile,
-		bytes.NewReader(nil)))
-
-	tv := vaultik.NewForTesting(store)
 	tv.Repositories = newLocalIndex(t, "snapshot-001")
 
 	result, err := tv.RemoveSnapshot("snapshot-001",

internal/vaultik/restore.go

@@ -103,11 +103,12 @@ type RestoreResult struct {
 	BlobsDownloaded int
 	BytesDownloaded int64
 	Duration        time.Duration
+	FilesFailed     int
+	FailedFiles     []string // Paths of files that failed to restore
 	// Verification results (only populated if Verify option is set)
-	FilesVerified int
+	FilesVerified     int
-	BytesVerified int64
+	BytesVerified     int64
-	FilesFailed   int
+	VerifyFailedFiles []string // Paths of restored files that failed verification
-	FailedFiles   []string // Paths of files that failed verification
 }
 
 // Restore restores files from a snapshot to the target directory
@@ -658,20 +659,34 @@ func (v *Vaultik) handleRestoreVerification(
 	opts *RestoreOptions,
 	result *RestoreResult,
 ) error {
-	err := v.verifyRestoredFiles(v.ctx, repos, files, opts.TargetDir, result)
+	// A file that failed to restore was not written and is already
+	// reported as such, so it is not verified.
+	failedToRestore := make(map[string]bool, len(result.FailedFiles))
+	for _, path := range result.FailedFiles {
+		failedToRestore[path] = true
+	}
+
+	restored := make([]*database.File, 0, len(files))
+	for _, file := range files {
+		if !failedToRestore[file.Path.String()] {
+			restored = append(restored, file)
+		}
+	}
+
+	err := v.verifyRestoredFiles(v.ctx, repos, restored, opts.TargetDir, result)
 	if err != nil {
 		return fmt.Errorf("verification failed: %w", err)
 	}
 
-	if result.FilesFailed > 0 {
+	if len(result.VerifyFailedFiles) > 0 {
 		v.UI.Errorf("Verification failed: %s files did not match expected checksums.",
-			v.UI.Count(result.FilesFailed))
+			v.UI.Count(len(result.VerifyFailedFiles)))
 
-		for _, path := range result.FailedFiles {
+		for _, path := range result.VerifyFailedFiles {
 			v.UI.Detailf("%s", v.UI.Path(path))
 		}
 
-		return fmt.Errorf("%d %w", result.FilesFailed, errFilesFailedVerify)
+		return fmt.Errorf("%d %w", len(result.VerifyFailedFiles), errFilesFailedVerify)
 	}
 
 	v.UI.Completef("Verified %s files (%s).",
@@ -1433,8 +1448,8 @@ func (v *Vaultik) verifyRestoredFiles(
 		if err != nil {
 			log.Error("File verification failed", "path", file.Path, "error", err)
 
-			result.FilesFailed++
+			result.VerifyFailedFiles = append(
-			result.FailedFiles = append(result.FailedFiles, file.Path.String())
+				result.VerifyFailedFiles, file.Path.String())
 		}
 
 		bytesProcessed += file.Size
@@ -1450,7 +1465,7 @@ func (v *Vaultik) verifyRestoredFiles(
 	log.Info("Verification complete",
 		"files_verified", result.FilesVerified,
 		"bytes_verified", ubytes(result.BytesVerified),
-		"files_failed", result.FilesFailed,
+		"files_failed", len(result.VerifyFailedFiles),
 	)
 
 	return nil

internal/vaultik/restore_another_machine_test.go

@@ -42,7 +42,7 @@ func TestRestoreOnAnotherMachine(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 

internal/vaultik/restore_interrupt_test.go

@@ -65,7 +65,7 @@ func TestRestoreCleansTempDirOnInterrupt(t *testing.T) {
 	root := t.TempDir()
 
 	dataDir := filepath.Join(root, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(root, "remote")
 	restoreDir := filepath.Join(root, "restored")
 	dbPath := filepath.Join(root, "index.sqlite")
 

internal/vaultik/restore_locality_test.go

@@ -197,7 +197,7 @@ func TestRestoreLocalityAndReadAt(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 

internal/vaultik/restore_perms_test.go

@@ -107,7 +107,7 @@ func backupOneFile(
 	require.NoError(t, afero.WriteFile(fs, srcPath, content, mode))
 	require.NoError(t, fs.Chmod(srcPath, mode))
 
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	storer, err := storage.NewFileStorer(storeDir)

internal/vaultik/restore_skip_errors_test.go

@@ -4,7 +4,9 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"github.com/spf13/afero"
@@ -104,6 +106,130 @@ func assertRestoreSkipsLostFiles(
 	}
 }
 
+// TestRestoreSkipErrorsVerifyChecksOnlyRestoredFiles restores with
+// SkipErrors and Verify after one blob of a two-blob snapshot was
+// deleted. Verification must check only the files that were written, so
+// a file of the deleted blob is reported as failed to restore and not
+// also as failing verification, and Restore must still return an error.
+func TestRestoreSkipErrorsVerifyChecksOnlyRestoredFiles(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	ctx := context.Background()
+	backup := backupThenDeleteOneBlob(ctx, t)
+
+	var out bytes.Buffer
+
+	v := newReaderVaultik(ctx, backup.cfg, backup.storer, nil, backup.fs)
+	v.UI = ui.NewWithColor(&out, false)
+
+	err := v.Restore(&vaultik.RestoreOptions{
+		SnapshotID: backup.snapshotID,
+		TargetDir:  backup.restoreDir,
+		Verify:     true,
+		SkipErrors: true,
+	})
+
+	require.Error(t, err, "restore must fail when files were skipped")
+	assert.Contains(t, err.Error(),
+		fmt.Sprintf("%d file(s) failed to restore", len(backup.lost)))
+
+	written := len(backup.files) - len(backup.lost)
+
+	assert.Contains(t, out.String(), fmt.Sprintf("Verifying %d files", written))
+	assert.Contains(t, out.String(), fmt.Sprintf("Verified %d files", written))
+	assert.NotContains(t, out.String(), "Verification failed")
+}
+
+// TestRestoreSkipErrorsVerifyReportsFailuresApart restores with
+// SkipErrors and Verify after one blob of a two-blob snapshot was
+// deleted, while one file that does restore is written one byte too long.
+// The restore warning must list only the files of the deleted blob, the
+// verification summary only the long file, each path once, and Restore
+// must return an error.
+func TestRestoreSkipErrorsVerifyReportsFailuresApart(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	ctx := context.Background()
+	backup := backupThenDeleteOneBlob(ctx, t)
+
+	var long string
+
+	for path := range backup.files {
+		if !backup.lost[path] {
+			long = path
+
+			break
+		}
+	}
+
+	var out bytes.Buffer
+
+	fs := trailingByteFs{Fs: backup.fs, suffix: long}
+	v := newReaderVaultik(ctx, backup.cfg, backup.storer, nil, fs)
+	v.UI = ui.NewWithColor(&out, false)
+
+	err := v.Restore(&vaultik.RestoreOptions{
+		SnapshotID: backup.snapshotID,
+		TargetDir:  backup.restoreDir,
+		Verify:     true,
+		SkipErrors: true,
+	})
+	require.Error(t, err, "restore must fail when files failed")
+
+	_, afterWarning, found := strings.Cut(out.String(),
+		fmt.Sprintf("%d file(s) failed to restore:", len(backup.lost)))
+	require.Truef(t, found, "no restore warning in:\n%s", out.String())
+
+	warning, summary, found := strings.Cut(afterWarning,
+		"Verification failed: 1 files did not match")
+	require.Truef(t, found, "no verification summary in:\n%s", out.String())
+
+	for path := range backup.lost {
+		assert.Equalf(t, 1, strings.Count(warning, path),
+			"%s must be listed once as failed to restore", path)
+		assert.NotContainsf(t, summary, path,
+			"%s was not restored and must not fail verification", path)
+	}
+
+	assert.NotContainsf(t, warning, long,
+		"%s was restored and must not be listed as failed to restore", long)
+	assert.Equalf(t, 1, strings.Count(summary, long),
+		"%s must be listed once as failing verification", long)
+}
+
+// trailingByteFs appends one byte, on close, to the file it opens whose
+// path ends in suffix, so that file is restored one byte too long and
+// fails verification.
+type trailingByteFs struct {
+	afero.Fs
+
+	suffix string
+}
+
+//nolint:ireturn // afero.Fs.OpenFile is defined to return the interface
+func (fs trailingByteFs) OpenFile(
+	name string, flag int, perm os.FileMode,
+) (afero.File, error) {
+	f, err := fs.Fs.OpenFile(name, flag, perm)
+	if err != nil || !strings.HasSuffix(name, fs.suffix) {
+		return f, err
+	}
+
+	return trailingByteFile{File: f}, nil
+}
+
+type trailingByteFile struct {
+	afero.File
+}
+
+func (f trailingByteFile) Close() error {
+	_, _ = f.Write([]byte{'x'})
+
+	return f.File.Close()
+}
+
 // TestRestoreMissingBlobAbortsWithoutSkipErrors checks that a deleted blob
 // still ends the restore with an error when SkipErrors is not set.
 func TestRestoreMissingBlobAbortsWithoutSkipErrors(t *testing.T) {
@@ -219,7 +345,7 @@ func backupSingleChunkFiles(
 		require.NoError(t, afero.WriteFile(fs, path, files[path], 0o644))
 	}
 
-	storer, err := storage.NewFileStorer(t.TempDir())
+	storer, err := storage.NewFileStorer(filepath.Join(tempDir, "remote"))
 	require.NoError(t, err)
 
 	db, err := database.New(ctx, dbPath)

internal/vaultik/restore_snapshot_identity_test.go

@@ -29,7 +29,7 @@ func TestRestoreAndDeepVerifyRejectSwappedDatabase(t *testing.T) {
 
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 
 	chunkSize := int64(64 * 1024)
 
@@ -100,7 +100,7 @@ func TestDeepVerifyRejectsSwappedDatabaseWithEmptyManifest(t *testing.T) {
 
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 
 	chunkSize := int64(64 * 1024)
 

internal/vaultik/restore_sweeper_integration_test.go

@@ -186,7 +186,7 @@ func TestRestoreSweeperEvictsBlobs(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 

internal/vaultik/restore_truncated_db_test.go

@@ -33,7 +33,7 @@ func TestRestoreRejectsTruncatedMetadataDB(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 

internal/vaultik/reused_blob_verify_test.go

@@ -28,7 +28,7 @@ func TestVerifyPassesWhenBackupReusesStoredBlob(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	secondDBPath := filepath.Join(tempDir, "second.sqlite")
 
 	chunkSize := int64(64 * 1024)

internal/vaultik/same_second_rewrite_test.go

@@ -25,7 +25,7 @@ func TestBackupOfSameSecondRewriteRestoresNewContent(t *testing.T) {
 	fs := afero.NewOsFs()
 	tempDir := t.TempDir()
 	dataDir := filepath.Join(tempDir, "src")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 	rewrittenPath := filepath.Join(dataDir, "small.txt")

internal/vaultik/shallow_verify_test.go

@@ -36,7 +36,7 @@ func TestShallowVerifyDetectsWrongBlobSize(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	chunkSize := int64(32 * 1024)
@@ -110,7 +110,7 @@ func TestShallowVerifyDetectsMissingDatabase(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	chunkSize := int64(32 * 1024)
@@ -193,7 +193,7 @@ func TestShallowVerifyReportsStatErrorsApartFromMissing(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	chunkSize := int64(32 * 1024)
@@ -282,7 +282,7 @@ func TestShallowVerifyQuietFailsOnStatErrorAlone(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	chunkSize := int64(32 * 1024)

internal/vaultik/snapshot.go

@@ -94,13 +94,6 @@ func (v *Vaultik) CreateSnapshot(opts *SnapshotCreateOptions) error {
 		return err
 	}
 
-	// Before PruneDatabase: it drops incomplete snapshots, which could
-	// leave the local index without one and so skip the marker check.
-	err = v.markDestination()
-	if err != nil {
-		return err
-	}
-
 	// Clean up incomplete snapshots FIRST, before any scanning.
 	// This is critical for data safety; PruneDatabase below does it.
 	hostname := v.Config.Hostname
@@ -123,9 +116,21 @@ func (v *Vaultik) CreateSnapshot(opts *SnapshotCreateOptions) error {
 		return fmt.Errorf("prune database: %w", err)
 	}
 
-	snapshotNames, err := v.snapshotNamesToCreate(opts.Snapshots)
+	// Determine which snapshots to process
-	if err != nil {
+	snapshotNames := opts.Snapshots
-		return err
+	if len(snapshotNames) == 0 {
+		snapshotNames = v.Config.SnapshotNames()
+	} else {
+		// Validate requested snapshot names exist
+		for _, name := range snapshotNames {
+			if _, ok := v.Config.Snapshots[name]; !ok {
+				return fmt.Errorf("%w: %q", errSnapshotNotInConfig, name)
+			}
+		}
+	}
+
+	if len(snapshotNames) == 0 {
+		return errNoSnapshotsInConfig
 	}
 
 	// Process each named snapshot
@@ -165,28 +170,6 @@ func (v *Vaultik) CreateSnapshot(opts *SnapshotCreateOptions) error {
 	return nil
 }
 
-// snapshotNamesToCreate returns the requested snapshot names, each checked
-// against the config, or every configured name when none was requested.
-func (v *Vaultik) snapshotNamesToCreate(requested []string) ([]string, error) {
-	snapshotNames := requested
-	if len(snapshotNames) == 0 {
-		snapshotNames = v.Config.SnapshotNames()
-	} else {
-		// Validate requested snapshot names exist
-		for _, name := range snapshotNames {
-			if _, ok := v.Config.Snapshots[name]; !ok {
-				return nil, fmt.Errorf("%w: %q", errSnapshotNotInConfig, name)
-			}
-		}
-	}
-
-	if len(snapshotNames) == 0 {
-		return nil, errNoSnapshotsInConfig
-	}
-
-	return snapshotNames, nil
-}
-
 // runPostBackupPrune drops older snapshots of the given names and removes
 // orphan blobs from remote storage. If keepNewerThan is set (e.g. "4w"),
 // snapshots newer than that duration are kept. Otherwise only the latest
@@ -644,7 +627,8 @@ func selectSnapshotsToPurge(
 }
 
 // confirmAndExecutePurge shows deletion candidates, confirms with the
-// user, and deletes snapshots.
+// user, and deletes snapshots. It stops with an error at the first
+// snapshot it cannot delete.
 func (v *Vaultik) confirmAndExecutePurge(
 	toDelete []SnapshotInfo, force, quiet bool,
 ) error {
@@ -686,10 +670,11 @@ func (v *Vaultik) confirmAndExecutePurge(
 		snapshotID := snap.ID.String()
 		log.Info("Deleting snapshot", "id", snapshotID)
 
+		// Stop before the remote delete: a snapshot still in the local
+		// index must keep its metadata on the destination store.
 		err := v.deleteSnapshotFromLocalDB(snapshotID)
 		if err != nil {
-			log.Error("Failed to delete from local database",
+			return fmt.Errorf("deleting snapshot %s from local index: %w", snapshotID, err)
-				"snapshot_id", snapshotID, "error", err)
 		}
 
 		_, err = v.deleteRemoteSnapshotByKey(snapshot.RemoteSnapshotKey(snapshotID))
@@ -1259,18 +1244,10 @@ func (v *Vaultik) RemoveSnapshot(
 		return v.removeSnapshotDryRun(result, snapshotID, opts)
 	}
 
-	if !v.confirmRemoveSnapshot(snapshotID, opts) {
+	if !opts.Force && !opts.JSON && !v.confirmRemoveSnapshot(snapshotID, opts) {
 		return result, nil
 	}
 
-	// Checked before the local record is deleted: it may be the last
-	// snapshot in the local index, and the check applies only while the
-	// local index holds one.
-	var markerErr error
-	if !opts.LocalOnly {
-		markerErr = v.checkDestinationMarker()
-	}
-
 	if inLocalIndex {
 		log.Info("Removing snapshot from local database", "snapshot_id", snapshotID)
 
@@ -1281,7 +1258,7 @@ func (v *Vaultik) RemoveSnapshot(
 	}
 
 	if !opts.LocalOnly {
-		result.RemoteRemoved = v.removeSnapshotRemote(snapshotID, markerErr, opts)
+		result.RemoteRemoved = v.removeSnapshotRemote(snapshotID, opts)
 	}
 
 	if v.SnapshotManager != nil {
@@ -1373,13 +1350,9 @@ func (v *Vaultik) removeSnapshotDryRun(
 }
 
 // confirmRemoveSnapshot prompts for confirmation before removing a
-// snapshot, unless --force or --json is set. Returns false (treating
+// snapshot. Returns false (treating EOF/read errors as "no") unless the
-// EOF/read errors as "no") unless the user answers "y".
+// user answers "y".
 func (v *Vaultik) confirmRemoveSnapshot(snapshotID string, opts *RemoveOptions) bool {
-	if opts.Force || opts.JSON {
-		return true
-	}
-
 	if opts.LocalOnly {
 		v.stdoutf("Remove snapshot '%s' from local database "+
 			"(remote untouched)? [y/N] ", snapshotID)
@@ -1411,24 +1384,15 @@ func (v *Vaultik) confirmRemoveSnapshot(snapshotID string, opts *RemoveOptions)
 // removal has already happened, so the user is told the remote half
 // didn't finish and to run `vaultik snapshot remove` for the snapshot
 // again once the destination store is reachable (`vaultik prune` never
-// removes snapshot metadata). markerErr is the result of
+// removes snapshot metadata). Returns true when the remote removal
-// checkDestinationMarker; when it is set, nothing is deleted and it is
+// succeeded and deleted something.
-// the failure reported. Returns true when the remote removal succeeded
+func (v *Vaultik) removeSnapshotRemote(snapshotID string, opts *RemoveOptions) bool {
-// and deleted something.
-func (v *Vaultik) removeSnapshotRemote(
-	snapshotID string, markerErr error, opts *RemoveOptions,
-) bool {
 	log.Info("Removing snapshot metadata from remote storage",
 		"snapshot_id", snapshotID)
 
-	var deleted int
+	remoteKey := snapshot.RemoteSnapshotKey(snapshotID)
-
-	err := markerErr
-	if err == nil {
-		deleted, err = v.deleteRemoteSnapshotByKey(
-			snapshot.RemoteSnapshotKey(snapshotID))
-	}
 
+	deleted, err := v.deleteRemoteSnapshotByKey(remoteKey)
 	if err != nil {
 		log.Warn("Could not remove snapshot metadata from remote storage; "+
 			"run '"+snapshotRemoveCommandHint+"' with the snapshot's ID "+
@@ -1532,8 +1496,8 @@ func (v *Vaultik) localSnapshotIDs() ([]string, error) {
 // listAllRemoteSnapshotKeys collects the hashed remote keys
 // (subdirectories under metadata/) currently present in the
 // destination store. Returns (nil, err) when the store cannot be
-// listed, or is not present by checkDestinationMarker; callers must
+// listed; callers must treat that as "no remote info available," not
-// treat that as "no remote info available," not fatal.
+// fatal.
 func (v *Vaultik) listAllRemoteSnapshotKeys() ([]string, error) {
 	log.Info("Listing all remote snapshots")
 
@@ -1582,11 +1546,6 @@ func (v *Vaultik) listAllRemoteSnapshotKeys() ([]string, error) {
 		}
 	}
 
-	err := v.checkDestinationMarker()
-	if err != nil {
-		return nil, err
-	}
-
 	return keys, nil
 }
 

internal/vaultik/snapshot_failed_file_test.go

@@ -87,7 +87,7 @@ func TestSnapshotSummaryCountsFileNotStoredAsFailed(t *testing.T) {
 				"src": {Paths: []string{srcDir}},
 			}
 
-			store, err := storage.NewFileStorer(t.TempDir())
+			store, err := storage.NewFileStorer(filepath.Join(tempDir, "remote"))
 			require.NoError(t, err)
 
 			db, err := database.New(ctx, cfg.IndexPath)

internal/vaultik/snapshot_list_test.go

@@ -122,9 +122,6 @@ func newListEnv(t *testing.T) *listEnv {
 	store := newObservingStorer()
 	stdout := &bytes.Buffer{}
 
-	// A backup wrote to this destination, so it carries the marker.
-	require.NoError(t, store.Put(ctx, markerFile, strings.NewReader("")))
-
 	v := &vaultik.Vaultik{
 		Config: &config.Config{
 			AgeSecretKey: "",
@@ -486,13 +483,14 @@ func TestListSnapshots_UnreadableManifestDoesNotHideOthers(t *testing.T) {
 //
 //nolint:tagliatelle // snake_case is the established output format
 type listJSONRow struct {
-	ID             string `json:"id"`
+	ID               string `json:"id"`
-	RemoteKey      string `json:"remote_key"`
+	RemoteKey        string `json:"remote_key"`
-	Timestamp      string `json:"timestamp"`
+	Timestamp        string `json:"timestamp"`
-	CompressedSize int64  `json:"compressed_size"`
+	CompressedSize   int64  `json:"compressed_size"`
-	NewChunkSize   int64  `json:"new_chunk_size"`
+	UncompressedSize int64  `json:"uncompressed_size"`
-	LocallyTracked bool   `json:"locally_tracked"`
+	NewChunkSize     int64  `json:"new_chunk_size"`
-	RemotePresent  *bool  `json:"remote_present"`
+	LocallyTracked   bool   `json:"locally_tracked"`
+	RemotePresent    *bool  `json:"remote_present"`
 }
 
 // decodeListJSON parses the command's stdout, which must contain

internal/vaultik/snapshot_skip_errors_test.go

@@ -45,7 +45,7 @@ func TestSkipErrorsBackupStopsOnIndexErrorRecordingDirectory(t *testing.T) {
 		"tree": {Paths: []string{srcDir}},
 	}
 
-	store, err := storage.NewFileStorer(t.TempDir())
+	store, err := storage.NewFileStorer(filepath.Join(tempDir, "remote"))
 	require.NoError(t, err)
 
 	db, err := database.New(ctx, cfg.IndexPath)

internal/vaultik/snapshot_summary_test.go

@@ -84,7 +84,7 @@ func newSummaryEnv(t *testing.T) *summaryEnv {
 		"split":  {Paths: []string{dirOne, dirTwo}},
 	}
 
-	inner, err := storage.NewFileStorer(t.TempDir())
+	inner, err := storage.NewFileStorer(filepath.Join(tempDir, "remote"))
 	require.NoError(t, err)
 
 	store := faultstore.New(inner)

internal/vaultik/two_path_snapshot_test.go

@@ -28,7 +28,7 @@ func TestBackupWithoutCronOfTwoPathSnapshotRestoresBothPaths(t *testing.T) {
 	tempDir := t.TempDir()
 	firstDir := filepath.Join(tempDir, "first")
 	secondDir := filepath.Join(tempDir, "second")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 

internal/vaultik/uncompressed_size_test.go

@@ -0,0 +1,85 @@
+package vaultik_test
+
+import (
+	"bytes"
+	"context"
+	"path/filepath"
+	"testing"
+
+	"github.com/spf13/afero"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/database"
+	"sneak.berlin/go/vaultik/internal/log"
+	"sneak.berlin/go/vaultik/internal/storage"
+	"sneak.berlin/go/vaultik/internal/vaultik"
+)
+
+// TestUncompressedSizeOfChangedFileStaysFixed covers
+// https://git.eeqj.de/sneak/vaultik/issues/360. A backup that changes a
+// file leaves the earlier snapshot's UNCOMPRESSED SIZE as it was when that
+// snapshot's backup completed. The file's row in the local index is shared
+// by both snapshots and rewritten by the second backup.
+func TestUncompressedSizeOfChangedFileStaysFixed(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	fs := afero.NewOsFs()
+	tempDir := t.TempDir()
+	dataDir := filepath.Join(tempDir, "src")
+	dbPath := filepath.Join(tempDir, "index.sqlite")
+	changedPath := filepath.Join(dataDir, "changed.bin")
+
+	ctx := context.Background()
+	files := writeFaultSourceTree(t, fs, dataDir)
+	cfg := changedFileConfig(dataDir, dbPath)
+
+	appendRandomBytes(t, fs, files, changedPath, appendedFileSize)
+
+	store, err := storage.NewFileStorer(filepath.Join(tempDir, "remote"))
+	require.NoError(t, err)
+
+	db, err := database.New(ctx, dbPath)
+	require.NoError(t, err)
+	t.Cleanup(func() { _ = db.Close() })
+
+	repos := database.NewRepositories(db)
+	v := newBackupVaultik(ctx, cfg, store, repos, db, fs)
+
+	require.NoError(t, backUp(v, "first"))
+
+	// With nothing to compare against, sizeOfNewChunks totals every
+	// distinct chunk of the files.
+	firstID := localSnapshotID(ctx, t, repos, "first")
+	firstSize := sizeOfNewChunks(t, files, nil)
+	require.Equal(t, firstSize, listedUncompressedSizes(t, v)[firstID],
+		"the first snapshot must count the chunks of every file it holds")
+
+	appendRandomBytes(t, fs, files, changedPath, faultChunkSize)
+	require.NoError(t, backUp(v, "second"))
+
+	secondID := localSnapshotID(ctx, t, repos, "second")
+	sizes := listedUncompressedSizes(t, v)
+	assert.Equal(t, firstSize, sizes[firstID],
+		"a later backup must not change the first snapshot's figure")
+	assert.Equal(t, sizeOfNewChunks(t, files, nil), sizes[secondID],
+		"the second snapshot must count the changed file's chunks")
+}
+
+// listedUncompressedSizes runs `snapshot list --json` and returns each
+// listed snapshot's uncompressed_size by snapshot ID.
+func listedUncompressedSizes(t *testing.T, v *vaultik.Vaultik) map[string]int64 {
+	t.Helper()
+
+	var out bytes.Buffer
+
+	v.Stdout = &out
+	require.NoError(t, v.ListSnapshots(true))
+
+	sizes := make(map[string]int64)
+	for _, row := range decodeListJSON(t, out.String()) {
+		sizes[row.ID] = row.UncompressedSize
+	}
+
+	return sizes
+}

internal/vaultik/verify.go

@@ -17,6 +17,7 @@ import (
 	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/log"
 	"sneak.berlin/go/vaultik/internal/snapshot"
+	"sneak.berlin/go/vaultik/internal/storage"
 )
 
 // Sentinel errors for snapshot verification failures.
@@ -32,7 +33,9 @@ var (
 	errManifestExtraBlob   = errors.New("manifest contains blob not in database")
 	errManifestMissingBlob = errors.New(
 		"manifest omits blob present in database")
-	errBlobSizeMismatch = errors.New("blob size mismatch")
+	errBlobSizeMismatch  = errors.New("blob size mismatch")
+	errBlobsNotInStorage = errors.New(
+		"blobs missing from storage or stored with the wrong size")
 )
 
 // verifyStatusFailed is the JSON status value for a failed verification.
@@ -149,7 +152,6 @@ func (v *Vaultik) RunDeepVerify(snapshotID string, opts *VerifyOptions) error {
 	}
 
 	result.Status = "ok"
-	result.Verified = len(dbBlobs)
 
 	if opts.JSON {
 		return v.outputVerifyJSON(result)
@@ -306,7 +308,7 @@ func (v *Vaultik) runVerificationSteps(
 		v.stdoutf("Checking blob existence in remote storage...\n")
 	}
 
-	err = v.verifyBlobExistenceFromDB(dbBlobs)
+	err = v.verifyBlobExistenceFromDB(dbBlobs, result)
 	if err != nil {
 		return v.deepVerifyFailure(result, opts, err.Error(), err)
 	}
@@ -317,7 +319,8 @@ func (v *Vaultik) runVerificationSteps(
 			len(dbBlobs), ubytes(totalSize))
 	}
 
-	err = v.performDeepVerificationFromDB(dbBlobs, tdb.db.Conn(), opts, identities)
+	err = v.performDeepVerificationFromDB(
+		dbBlobs, tdb.db.Conn(), opts, result, identities)
 	if err != nil {
 		return v.deepVerifyFailure(result, opts, err.Error(), err)
 	}
@@ -669,8 +672,14 @@ func (v *Vaultik) verifyManifestAgainstDatabase(
 	return nil
 }
 
-// verifyBlobExistenceFromDB checks that all blobs from database exist in S3
+// verifyBlobExistenceFromDB checks that every blob from the database is
-func (v *Vaultik) verifyBlobExistenceFromDB(blobs []snapshot.BlobInfo) error {
+// in storage with the size the database records. It checks them all,
+// counting the missing and wrong-size blobs in result, and fails if it
+// found any. Any storage error other than not found stops the check and
+// fails with that error.
+func (v *Vaultik) verifyBlobExistenceFromDB(
+	blobs []snapshot.BlobInfo, result *VerifyResult,
+) error {
 	log.Info("Verifying blob existence in S3", "blob_count", len(blobs))
 
 	for i, blob := range blobs {
@@ -683,17 +692,23 @@ func (v *Vaultik) verifyBlobExistenceFromDB(blobs []snapshot.BlobInfo) error {
 		// Construct blob path
 		blobPath := fmt.Sprintf("blobs/%s/%s/%s", blob.Hash[:2], blob.Hash[2:4], blob.Hash)
 
-		// Check blob exists
 		stat, err := v.Storage.Stat(v.ctx, blobPath)
-		if err != nil {
+		switch {
-			return fmt.Errorf("blob %s missing from storage: %w", blob.Hash, err)
+		case errors.Is(err, storage.ErrNotFound):
-		}
+			log.Warn("Blob missing from storage", "hash", blob.Hash)
 
-		// Verify size matches
+			result.Missing++
-		if stat.Size != blob.CompressedSize {
+			result.MissingSize += blob.CompressedSize
-			return fmt.Errorf(
+		case err != nil:
-				"%w: blob %s: S3 has %d bytes, database has %d bytes",
+			return fmt.Errorf("checking blob %s in storage: %w",
-				errBlobSizeMismatch, blob.Hash, stat.Size, blob.CompressedSize)
+				blob.Hash, err)
+		case stat.Size != blob.CompressedSize:
+			log.Warn("Blob has the wrong size in storage",
+				"hash", blob.Hash,
+				"storage_size", stat.Size,
+				"database_size", blob.CompressedSize)
+
+			result.Mismatched++
 		}
 
 		// Progress update every 100 blobs
@@ -707,16 +722,22 @@ func (v *Vaultik) verifyBlobExistenceFromDB(blobs []snapshot.BlobInfo) error {
 		}
 	}
 
+	if result.Missing > 0 || result.Mismatched > 0 {
+		return fmt.Errorf("%w: %d missing, %d with the wrong size",
+			errBlobsNotInStorage, result.Missing, result.Mismatched)
+	}
+
 	log.Info("✓ All blobs exist in storage")
 
 	return nil
 }
 
 // performDeepVerificationFromDB downloads and verifies the content of
-// each blob using the database as source.
+// each blob using the database as source, stopping at the first blob that
+// fails. Each blob that passes is counted in result.Verified.
 func (v *Vaultik) performDeepVerificationFromDB(
 	blobs []snapshot.BlobInfo, db *sql.DB, opts *VerifyOptions,
-	identities []age.Identity,
+	result *VerifyResult, identities []age.Identity,
 ) error {
 	// Calculate total bytes for ETA
 	var totalBytesExpected int64
@@ -739,6 +760,7 @@ func (v *Vaultik) performDeepVerificationFromDB(
 			return fmt.Errorf("blob %s verification failed: %w", blobInfo.Hash, err)
 		}
 
+		result.Verified++
 		bytesProcessed += blobInfo.CompressedSize
 		elapsed := time.Since(startTime)
 		remaining := len(blobs) - (i + 1)

internal/vaultik/verify_quiet_test.go

@@ -28,7 +28,7 @@ func TestVerify_QuietSuppressesReport(t *testing.T) {
 	tempDir := t.TempDir()
 
 	dataDir := filepath.Join(tempDir, "source")
-	storeDir := t.TempDir()
+	storeDir := filepath.Join(tempDir, "remote")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 
 	chunkSize := int64(32 * 1024)