Record the stored size of a blob a backup finds already stored (closes #300)

When a finished blob already existed at the destination, the upload was
skipped but the blob row, and so the manifest, kept the size of the
local copy. That copy differs from the stored object when
compression_level or the recipients changed since it was written, so
shallow and deep verify failed on a good snapshot. Marking a blob
uploaded now records the size of the object in storage: for an existing
blob, the size Stat reports.

Judgement call: the test adds a recipient rather than changing the
compression level, because an extra age recipient always makes the
local copy larger, while two zstd levels need not compress the test
data differently.

Model: opus-5-5

README.md

@@ -384,12 +384,10 @@ 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 a blob cannot be deleted, the
-command (and `snapshot create --prune`) exits non-zero.
+manual entry point for the same work.
 * `--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
-  `blobs_failed`, and the document is printed before the non-zero exit.
+  `--force` does.
 
 **`info`**: Display system configuration, storage settings, encryption
 recipients, and local database statistics.
@@ -409,8 +407,7 @@ snapshot's blob count and blob size unknown, `null` in `--json`.
 **`remote nuke`**: Delete every snapshot's metadata and every blob from the
 backup destination store, leaving the bucket prefix empty. Destructive and
 irreversible. This is the single supported way to wipe the entire
-destination store. If anything cannot be deleted, the command exits
-non-zero; running it again deletes what is left.
+destination store.
 * `--force`: Required to confirm destruction.
 
 **`database delete`**: Delete the local SQLite state database file

TODO.md

@@ -22,16 +22,15 @@ the tag exists and is exercised; what is left is merging `next` to
 
 # Completed Steps
 
-- 2026-10-13: Made `prune` and `remote nuke` exit non-zero when a delete
-  fails ([issue #290](https://git.eeqj.de/sneak/vaultik/issues/290)).
-  `prune`, and the prune step of `snapshot create --prune`, counted a
-  blob it could not delete and still exited 0; it now prints its summary
-  or `--json` document and then fails. `remote nuke` warned about a
-  snapshot's metadata it could not delete, said to run `vaultik prune`,
-  which never removes metadata, and then reported the store empty. It
-  now fails without that report and says to run `vaultik remote nuke
-  --force` again, and a successful nuke no longer advises `prune` for
-  blobs it deletes itself.
+- 2026-10-13: Recorded the size of the stored object for a blob a backup
+  found already stored
+  ([issue #300](https://git.eeqj.de/sneak/vaultik/issues/300)). When the
+  upload was skipped, the blob row and the manifest kept the size of the
+  local copy, which differs from the stored object's when
+  `compression_level` or the recipients changed since it was written.
+  `snapshot verify` then failed on a good snapshot, shallow and deep,
+  and the listed sizes were wrong. Marking the blob uploaded now records
+  the size of the object in storage.
 
 - 2026-10-13: Made `snapshot remove` fail for a snapshot that does not
   exist ([issue #293](https://git.eeqj.de/sneak/vaultik/issues/293)).

docs/DATAMODEL.md

@@ -90,7 +90,7 @@ Stores information about packed, compressed, and encrypted blob files.
 - `created_ts` (INTEGER NOT NULL) - Creation timestamp
 - `finished_ts` (INTEGER) - Finalization timestamp (NULL if in progress)
 - `uncompressed_size` (INTEGER NOT NULL DEFAULT 0) - Total size of chunks before compression
-- `compressed_size` (INTEGER NOT NULL DEFAULT 0) - Size after compression and encryption
+- `compressed_size` (INTEGER NOT NULL DEFAULT 0) - Size after compression and encryption. Once uploaded, the size of the object in storage: when the blob was already stored, under another compression level or other recipients, this differs from the size of the local copy
 - `uploaded_ts` (INTEGER) - Upload completion timestamp (NULL if not uploaded)
 
 **Purpose:** Tracks blob lifecycle from creation through upload. The UUID primary key allows immediate association of chunks with blobs.
@@ -183,7 +183,7 @@ Tracks blob upload metrics.
    - `UPDATE blobs SET blob_hash = ?, finished_ts = ?` - Finalize blob after packing
 
 4. **Upload**
-   - `UPDATE blobs SET uploaded_ts = ?` - Mark blob as uploaded
+   - `UPDATE blobs SET uploaded_ts = ?, compressed_size = ?` - Mark blob as uploaded, with the size of the object in storage (the upload is skipped when the blob is already stored)
    - `INSERT INTO uploads` - Record upload metrics with snapshot_id
    - `INSERT INTO snapshot_blobs` - Associate blob with snapshot
 

internal/database/blobs.go

@@ -159,13 +159,16 @@ func (r *BlobRepository) UpdateFinished(
 	return nil
 }
 
-// UpdateUploaded marks a blob as uploaded
+// UpdateUploaded marks a blob as uploaded and records the size of the
+// stored object as its compressed size. That size can differ from the
+// local copy's when an identical blob was already stored with another
+// compression level or other recipients.
 func (r *BlobRepository) UpdateUploaded(
-	ctx context.Context, tx *sql.Tx, id string,
+	ctx context.Context, tx *sql.Tx, id string, storedSize int64,
 ) error {
 	query := `
-		UPDATE blobs 
-		SET uploaded_ts = ?
+		UPDATE blobs
+		SET uploaded_ts = ?, compressed_size = ?
 		WHERE id = ?
 	`
 
@@ -173,9 +176,9 @@ func (r *BlobRepository) UpdateUploaded(
 
 	var err error
 	if tx != nil {
-		_, err = tx.ExecContext(ctx, query, now, id)
+		_, err = tx.ExecContext(ctx, query, now, storedSize, id)
 	} else {
-		_, err = r.db.ExecWithLog(ctx, query, now, id)
+		_, err = r.db.ExecWithLog(ctx, query, now, storedSize, id)
 	}
 
 	if err != nil {

internal/database/blobs_test.go

@@ -122,8 +122,8 @@ func TestBlobRepositoryUpdates(t *testing.T) {
 		t.Errorf("expected compressed size 500, got %d", updated.CompressedSize)
 	}
 
-	// Test UpdateUploaded
-	err = repo.UpdateUploaded(ctx, nil, blob.ID.String())
+	// Test UpdateUploaded, with a stored object larger than the local copy
+	err = repo.UpdateUploaded(ctx, nil, blob.ID.String(), 600)
 	if err != nil {
 		t.Fatalf("failed to update blob as uploaded: %v", err)
 	}
@@ -141,6 +141,10 @@ func TestBlobRepositoryUpdates(t *testing.T) {
 	if uploaded.UploadedTS.Before(now.Add(-1 * time.Second)) {
 		t.Error("uploaded timestamp should be around test time")
 	}
+
+	if uploaded.CompressedSize != 600 {
+		t.Errorf("expected the stored size 600, got %d", uploaded.CompressedSize)
+	}
 }
 
 func TestBlobRepositoryDuplicate(t *testing.T) {

internal/snapshot/scanner.go

@@ -1509,7 +1509,8 @@ func (s *Scanner) finalizeProcessPhase(ctx context.Context, result *ScanResult)
 			// snapshot references has uploaded_ts set, so deduplication and
 			// interrupted-run repair treat these blobs as trustworthy.
 			err = s.repos.WithTx(ctx, func(ctx context.Context, tx *sql.Tx) error {
-				err := s.repos.Blobs.UpdateUploaded(ctx, tx, b.ID)
+				err := s.repos.Blobs.UpdateUploaded(
+					ctx, tx, b.ID, b.Compressed)
 				if err != nil {
 					return fmt.Errorf("marking blob uploaded: %w", err)
 				}
@@ -1545,7 +1546,7 @@ func (s *Scanner) handleBlobReady(
 	blobPath := fmt.Sprintf("blobs/%s/%s/%s",
 		finishedBlob.Hash[:2], finishedBlob.Hash[2:4], finishedBlob.Hash)
 
-	blobExists, err := s.uploadBlobIfNeeded(
+	storedSize, blobExists, err := s.uploadBlobIfNeeded(
 		ctx, blobPath, blobWithReader, startTime, result)
 	if err != nil {
 		s.cleanupBlobTempFile(blobWithReader)
@@ -1553,7 +1554,8 @@ func (s *Scanner) handleBlobReady(
 		return fmt.Errorf("uploading blob %s: %w", finishedBlob.Hash, err)
 	}
 
-	err = s.recordBlobMetadata(ctx, finishedBlob, blobExists, startTime)
+	err = s.recordBlobMetadata(
+		ctx, finishedBlob, storedSize, blobExists, startTime)
 	if err != nil {
 		s.cleanupBlobTempFile(blobWithReader)
 
@@ -1575,20 +1577,22 @@ func (s *Scanner) handleBlobReady(
 }
 
 // uploadBlobIfNeeded uploads the blob to storage if it doesn't already
-// exist, returns whether it existed
+// exist. It returns the size of the object in storage, which for an
+// existing object can differ from the local copy's, and whether it
+// already existed.
 func (s *Scanner) uploadBlobIfNeeded(
 	ctx context.Context,
 	blobPath string,
 	blobWithReader *blob.WithReader,
 	startTime time.Time,
 	result *ScanResult,
-) (bool, error) {
+) (int64, bool, error) {
 	finishedBlob := blobWithReader.FinishedBlob
 
 	// Check if blob already exists (deduplication after restart)
 	destination := s.storage.Info().Location
 
-	_, err := s.storage.Stat(ctx, blobPath)
+	stored, err := s.storage.Stat(ctx, blobPath)
 	if err == nil {
 		log.Info("Blob already exists in storage, skipping upload",
 			"hash", finishedBlob.Hash,
@@ -1597,7 +1601,7 @@ func (s *Scanner) uploadBlobIfNeeded(
 			s.ui.Hex(finishedBlob.Hash), s.ui.Size(finishedBlob.Compressed),
 			s.ui.Path(destination))
 
-		return true, nil
+		return stored.Size, true, nil
 	}
 
 	s.ui.Beginf("Uploading blob %s (%s) to %s.",
@@ -1611,7 +1615,7 @@ func (s *Scanner) uploadBlobIfNeeded(
 	if err != nil {
 		log.Error("Failed to upload blob", "hash", finishedBlob.Hash, "error", err)
 
-		return false, fmt.Errorf("uploading blob to storage: %w", err)
+		return 0, false, fmt.Errorf("uploading blob to storage: %w", err)
 	}
 
 	uploadDuration := time.Since(startTime)
@@ -1642,7 +1646,7 @@ func (s *Scanner) uploadBlobIfNeeded(
 		stats.BytesUploaded.Add(finishedBlob.Compressed)
 	}
 
-	return false, nil
+	return finishedBlob.Compressed, false, nil
 }
 
 // makeUploadProgressCallback creates a progress callback for blob uploads.
@@ -1712,6 +1716,7 @@ func (s *Scanner) makeUploadProgressCallback(
 func (s *Scanner) recordBlobMetadata(
 	ctx context.Context,
 	finishedBlob *blob.FinishedBlob,
+	storedSize int64,
 	blobExists bool,
 	startTime time.Time,
 ) error {
@@ -1723,7 +1728,8 @@ func (s *Scanner) recordBlobMetadata(
 	uploadDuration := time.Since(startTime)
 
 	return s.repos.WithTx(ctx, func(txCtx context.Context, tx *sql.Tx) error {
-		err := s.repos.Blobs.UpdateUploaded(txCtx, tx, finishedBlob.ID)
+		err := s.repos.Blobs.UpdateUploaded(
+			txCtx, tx, finishedBlob.ID, storedSize)
 		if err != nil {
 			return fmt.Errorf("updating blob upload timestamp: %w", err)
 		}

internal/storage/faultstore/faultstore.go

@@ -1,16 +1,15 @@
 // Package faultstore provides a storage.Storer wrapper that injects
 // faults on demand, so tests can reproduce the failure modes a real
 // backend exhibits: an upload that fails partway, a backend that reports
-// success while storing nothing, reads that return corrupt or truncated
-// bytes, and a delete the backend refuses. It is the seam called for by
-// the fault-injection tests (sneak/vaultik issue 72) and is meant to be
-// reused by future tests rather than re-implemented per case.
+// success while storing nothing, and reads that return corrupt or
+// truncated bytes. It is the seam called for by the fault-injection
+// tests (sneak/vaultik issue 72) and is meant to be reused by future
+// tests rather than re-implemented per case.
 //
-// The wrapper delegates every method to the inner Storer. Three hooks
-// change that: OnPut decides the fate of each write, OnGet decides how
-// each read's bytes are returned, and OnDelete decides whether each
-// delete fails. All are keyed by the object key, so a test can fault
-// only blobs, only metadata, or a single object.
+// The wrapper delegates every method to the inner Storer. Two hooks
+// change that: OnPut decides the fate of each write, and OnGet decides
+// how each read's bytes are returned. Both are keyed by the object key,
+// so a test can fault only blobs, only metadata, or a single object.
 package faultstore
 
 import (
@@ -26,10 +25,6 @@ import (
 // ErrInjectedUpload is returned by a Put the OnPut hook chose to fail.
 var ErrInjectedUpload = errors.New("faultstore: injected upload failure")
 
-// ErrInjectedDelete is returned by a Delete the OnDelete hook chose to
-// fail.
-var ErrInjectedDelete = errors.New("faultstore: injected delete failure")
-
 // PutAction is the disposition OnPut assigns to a write.
 type PutAction int
 
@@ -71,11 +66,6 @@ type Storer struct {
 	// OnGet, when set, is consulted for every Get with the object key
 	// and damages the returned bytes accordingly.
 	OnGet func(key string) GetFault
-
-	// OnDelete, when set, is consulted before every Delete with the
-	// object key. Returning true fails the delete and leaves the object
-	// in place.
-	OnDelete func(key string) bool
 }
 
 // New wraps inner. inner must be non-nil.
@@ -164,12 +154,8 @@ func (f *Storer) Stat(ctx context.Context, key string) (*storage.ObjectInfo, err
 	return f.inner.Stat(ctx, key)
 }
 
-// Delete removes the object unless OnDelete fails the delete.
+// Delete delegates unchanged.
 func (f *Storer) Delete(ctx context.Context, key string) error {
-	if f.OnDelete != nil && f.OnDelete(key) {
-		return fmt.Errorf("%w for %q", ErrInjectedDelete, key)
-	}
-
 	return f.inner.Delete(ctx, key)
 }
 

internal/vaultik/nuke_remote_test.go

@@ -5,14 +5,12 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
-	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"sneak.berlin/go/vaultik/internal/log"
 	"sneak.berlin/go/vaultik/internal/snapshot"
-	"sneak.berlin/go/vaultik/internal/storage/faultstore"
 )
 
 // TestNukeRemoteLeavesNoFiles checks that remote nuke leaves no file
@@ -25,7 +23,7 @@ func TestNukeRemoteLeavesNoFiles(t *testing.T) {
 
 	ctx := context.Background()
 	storeDir := filepath.Join(t.TempDir(), "store")
-	v, repos, out := backUpToFileDestination(ctx, t, storeDir)
+	v, repos, _ := backUpToFileDestination(ctx, t, storeDir)
 
 	snapshots, err := repos.Snapshots.ListRecent(ctx, listRecentTestLimit)
 	require.NoError(t, err)
@@ -63,82 +61,4 @@ func TestNukeRemoteLeavesNoFiles(t *testing.T) {
 		})
 	require.NoError(t, err)
 	assert.Empty(t, files)
-
-	// Nuke deletes the blobs itself, so advice to run prune is wrong.
-	assert.Contains(t, out.String(), "Backup destination store is now empty.")
-	assert.NotContains(t, out.String(), "vaultik prune")
-}
-
-// TestNukeRemoteFailsWhenADeleteFails checks that remote nuke returns an
-// error when a snapshot's metadata or a blob cannot be deleted, does not
-// report the store empty, and advises running nuke again: prune deletes
-// no metadata.
-func TestNukeRemoteFailsWhenADeleteFails(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	for _, refusedPrefix := range []string{"metadata/", "blobs/"} {
-		t.Run(refusedPrefix, func(t *testing.T) {
-			t.Parallel()
-
-			ctx := context.Background()
-			storeDir := filepath.Join(t.TempDir(), "store")
-			v, _, out := backUpToFileDestination(ctx, t, storeDir)
-
-			store := faultstore.New(v.Storage)
-			store.OnDelete = func(key string) bool {
-				return strings.HasPrefix(key, refusedPrefix)
-			}
-			v.Storage = store
-
-			require.Error(t, v.NukeRemote(true))
-
-			assert.NotContains(t, out.String(), "now empty")
-			assert.Contains(t, out.String(), "vaultik remote nuke --force")
-			assert.NotContains(t, out.String(), "vaultik prune")
-		})
-	}
-}
-
-// TestNukeRemoteRefusesAnotherDestinationWithoutRetryAdvice checks that
-// remote nuke, when the local index belongs to a different destination
-// than the configured one, fails without advising to run nuke again:
-// that run would fail the same way.
-func TestNukeRemoteRefusesAnotherDestinationWithoutRetryAdvice(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	storeDir := filepath.Join(t.TempDir(), "store")
-	v, _, out := backUpToFileDestination(ctx, t, storeDir)
-
-	v.Config.StorageURL = "file://" + filepath.Join(t.TempDir(), "elsewhere")
-
-	err := v.NukeRemote(true)
-
-	require.ErrorContains(t, err, "bound to a different backup destination")
-	assert.NotContains(t, out.String(), "vaultik remote nuke --force")
-}
-
-// TestNukeRemoteFailsWhenALocalSnapshotCannotBeRemoved checks that a
-// snapshot remote nuke cannot remove from the local index fails the
-// run: nuke then leaves that snapshot's metadata on the destination
-// store.
-func TestNukeRemoteFailsWhenALocalSnapshotCannotBeRemoved(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	storeDir := filepath.Join(t.TempDir(), "store")
-	v, _, out := backUpToFileDestination(ctx, t, storeDir)
-
-	_, err := v.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.Error(t, v.NukeRemote(true))
-
-	assert.NotContains(t, out.String(), "now empty")
-	assert.Contains(t, out.String(), "vaultik remote nuke --force")
 }

internal/vaultik/prune.go

@@ -19,14 +19,6 @@ type PruneOptions struct {
 var errNukeRequiresForce = errors.New(
 	"nuke requires --force (this deletes ALL remote snapshots and blobs)")
 
-// errBlobDeleteFailed reports unreferenced blobs prune could not delete.
-var errBlobDeleteFailed = errors.New("blob(s) could not be deleted")
-
-// nukeCommandHint is the command suggested when a remote nuke could not
-// delete everything: running it again deletes what is left, which
-// `vaultik prune` does not do for snapshot metadata.
-const nukeCommandHint = "vaultik remote nuke --force"
-
 // metadataDirName is the top-level remote directory holding snapshot
 // metadata.
 const metadataDirName = "metadata"
@@ -43,29 +35,6 @@ func (v *Vaultik) NukeRemote(force bool) error {
 		return errNukeRequiresForce
 	}
 
-	// Checked before anything is deleted: running nuke again would fail
-	// the same way, so the advice below must not follow this error.
-	err := v.EnsureStorageBinding()
-	if err != nil {
-		return err
-	}
-
-	err = v.emptyDestinationStore()
-	if err != nil {
-		v.UI.Warningf("Run '%s' again to delete what is left on the "+
-			"backup destination store.", nukeCommandHint)
-
-		return err
-	}
-
-	v.UI.Completef("Backup destination store is now empty.")
-
-	return nil
-}
-
-// emptyDestinationStore does the deleting for NukeRemote and stops at
-// the first step that fails.
-func (v *Vaultik) emptyDestinationStore() error {
 	v.UI.Beginf("Removing all snapshot metadata from backup destination store.")
 
 	_, err := v.RemoveAllSnapshots(&RemoveOptions{Force: true})
@@ -89,6 +58,8 @@ func (v *Vaultik) emptyDestinationStore() error {
 		}
 	}
 
+	v.UI.Completef("Backup destination store is now empty.")
+
 	return nil
 }
 
@@ -191,17 +162,14 @@ func (v *Vaultik) PruneBlobs(opts *PruneOptions) error {
 	v.deleteUnreferencedBlobs(unreferencedBlobs, allBlobs, result)
 
 	if opts.JSON {
-		err = v.outputPruneBlobsJSON(result)
-		if err != nil {
-			return err
-		}
-	} else {
-		v.stdoutf("\nDeleted %d blob(s) totaling %s\n",
-			result.BlobsDeleted, ubytes(result.BytesFreed))
+		return v.outputPruneBlobsJSON(result)
 	}
 
+	v.stdoutf("\nDeleted %d blob(s) totaling %s\n",
+		result.BlobsDeleted, ubytes(result.BytesFreed))
+
 	if result.BlobsFailed > 0 {
-		return fmt.Errorf("%d %w", result.BlobsFailed, errBlobDeleteFailed)
+		v.stdoutf("Failed to delete %d blob(s)\n", result.BlobsFailed)
 	}
 
 	return nil

internal/vaultik/prune_delete_failure_test.go

@@ -1,98 +0,0 @@
-package vaultik_test
-
-import (
-	"context"
-	"encoding/json"
-	"os"
-	"path/filepath"
-	"strings"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"sneak.berlin/go/vaultik/internal/log"
-	"sneak.berlin/go/vaultik/internal/storage/faultstore"
-	"sneak.berlin/go/vaultik/internal/vaultik"
-)
-
-// refuseBlobDeletes is an OnDelete hook that fails every blob delete.
-func refuseBlobDeletes(key string) bool {
-	return strings.HasPrefix(key, "blobs/")
-}
-
-// TestPruneBlobs_FailedDeleteReturnsError checks that prune returns an
-// error, so the command exits non-zero, when an unreferenced blob cannot
-// be deleted.
-func TestPruneBlobs_FailedDeleteReturnsError(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	env := newListEnv(t)
-
-	// The store holds no manifest, so nothing references this blob.
-	addBlob(t, env.store.testStorer, testBlobHashA)
-
-	store := faultstore.New(env.store)
-	store.OnDelete = refuseBlobDeletes
-	env.v.Storage = store
-
-	err := env.v.PruneBlobs(&vaultik.PruneOptions{Force: true})
-
-	require.ErrorContains(t, err, "1 blob(s) could not be deleted")
-}
-
-// TestPruneBlobs_JSONFailedDeleteReturnsError checks that prune --json
-// prints its document and then returns an error when an unreferenced
-// blob cannot be deleted.
-func TestPruneBlobs_JSONFailedDeleteReturnsError(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	env := newListEnv(t)
-	addBlob(t, env.store.testStorer, testBlobHashA)
-
-	store := faultstore.New(env.store)
-	store.OnDelete = refuseBlobDeletes
-	env.v.Storage = store
-
-	err := env.v.PruneBlobs(&vaultik.PruneOptions{JSON: true})
-
-	require.Error(t, err, "prune must fail when a blob cannot be deleted")
-
-	var result vaultik.PruneBlobsResult
-
-	require.NoError(t, json.Unmarshal(env.stdout.Bytes(), &result),
-		"stdout must hold the JSON document, got:\n%s", env.stdout.String())
-	assert.Equal(t, 1, result.BlobsFailed)
-	assert.Equal(t, 0, result.BlobsDeleted)
-}
-
-// TestCreateSnapshotPrune_FailedBlobDeleteReturnsError checks that the
-// prune step of snapshot create --prune fails the run when an
-// unreferenced blob cannot be deleted.
-func TestCreateSnapshotPrune_FailedBlobDeleteReturnsError(t *testing.T) {
-	log.Initialize(log.Config{})
-	t.Parallel()
-
-	ctx := context.Background()
-	storeDir := filepath.Join(t.TempDir(), "store")
-	v, _, _ := backUpToFileDestination(ctx, t, storeDir)
-
-	// No snapshot references this blob, so the prune step deletes it.
-	orphan := filepath.Join(storeDir, "blobs", testBlobHashA[:2],
-		testBlobHashA[2:4], testBlobHashA)
-	require.NoError(t, os.MkdirAll(filepath.Dir(orphan), 0o750))
-	require.NoError(t, os.WriteFile(orphan, []byte("orphan"), 0o600))
-
-	store := faultstore.New(v.Storage)
-	store.OnDelete = refuseBlobDeletes
-	v.Storage = store
-
-	err := v.CreateSnapshot(&vaultik.SnapshotCreateOptions{
-		Cron:  true,
-		Prune: true,
-	})
-
-	require.ErrorContains(t, err, "1 blob(s) could not be deleted")
-	assert.FileExists(t, orphan)
-}

internal/vaultik/remove_snapshot_test.go

@@ -476,8 +476,7 @@ func TestRemoveAllSnapshots_WithForce(t *testing.T) {
 	out := tv.Stdout.String()
 	assert.Contains(t, out, "Removed 2 snapshot(s)")
 	assert.Contains(t, out, "Removed snapshot metadata from remote storage")
-	// Remote nuke, the only caller, deletes the blobs next itself.
-	assert.NotContains(t, out, "vaultik prune")
+	assert.Contains(t, out, "vaultik prune")
 }
 
 func TestRemoveAllSnapshots_DryRun(t *testing.T) {

internal/vaultik/reused_blob_verify_test.go

@@ -0,0 +1,83 @@
+package vaultik_test
+
+import (
+	"context"
+	"io"
+	"path/filepath"
+	"testing"
+
+	"filippo.io/age"
+	"github.com/spf13/afero"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/log"
+	"sneak.berlin/go/vaultik/internal/ui"
+	"sneak.berlin/go/vaultik/internal/vaultik"
+)
+
+// TestVerifyPassesWhenBackupReusesStoredBlob backs up a file, then backs it
+// up again from an empty local index, as after `database delete`, with an
+// extra age recipient. The second backup builds the same blob, finds it
+// already stored and skips the upload, but its own copy is larger, because
+// age writes a header entry for each recipient. The second snapshot must
+// record the size of the stored object, so shallow and deep verify pass.
+func TestVerifyPassesWhenBackupReusesStoredBlob(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	fs := afero.NewOsFs()
+	tempDir := t.TempDir()
+
+	dataDir := filepath.Join(tempDir, "source")
+	storeDir := filepath.Join(tempDir, "remote")
+	secondDBPath := filepath.Join(tempDir, "second.sqlite")
+
+	chunkSize := int64(64 * 1024)
+	maxBlobSize := int64(512 * 1024)
+
+	require.NoError(t, fs.MkdirAll(dataDir, 0o755))
+	require.NoError(t, afero.WriteFile(fs,
+		filepath.Join(dataDir, "data.bin"),
+		bytesPattern("reuse-", int(chunkSize*3)), 0o644))
+
+	ctx := context.Background()
+
+	runFileStorageBackup(ctx, t, fs, dataDir, storeDir,
+		filepath.Join(tempDir, "first.sqlite"), chunkSize, maxBlobSize)
+
+	env := setupDedupBackupEnv(
+		ctx, t, fs, storeDir, secondDBPath, chunkSize, maxBlobSize)
+
+	defer func() { _ = env.db.Close() }()
+
+	extra, err := age.GenerateX25519Identity()
+	require.NoError(t, err)
+
+	env.cfg.AgeRecipients = append(env.cfg.AgeRecipients,
+		extra.Recipient().String())
+
+	snapshotID, result := runDedupSnapshot(ctx, t, env.sm, env.makeScanner(),
+		env.cfg.Hostname, "second", dataDir, secondDBPath)
+	require.Positive(t, result.BlobsCreated)
+	require.Zero(t, result.BlobsUploaded,
+		"the second backup should find every blob already stored")
+
+	require.NoError(t, env.db.Close())
+
+	verifier := &vaultik.Vaultik{
+		Config:  env.cfg,
+		Storage: env.storer,
+		Fs:      fs,
+		Stdout:  io.Discard,
+		Stderr:  io.Discard,
+		UI:      ui.NewWithColor(io.Discard, false),
+	}
+	verifier.SetContext(ctx)
+
+	require.NoError(t,
+		verifier.VerifySnapshotWithOptions(snapshotID, &vaultik.VerifyOptions{}),
+		"shallow verify should pass")
+	require.NoError(t,
+		verifier.VerifySnapshotWithOptions(snapshotID,
+			&vaultik.VerifyOptions{Deep: true}),
+		"deep verify should pass")
+}

internal/vaultik/snapshot.go

@@ -24,7 +24,6 @@ var (
 	errSnapshotVerifyFailed = errors.New("verification failed")
 	errRemoveAllNeedsForce  = errors.New("--all requires --force")
 	errSnapshotNotFound     = errors.New("snapshot not found")
-	errSnapshotRemoveFailed = errors.New("snapshot(s) could not be removed")
 	errInvalidTableName     = errors.New("invalid table name")
 	errNoAgeRecipients      = errors.New(
 		"creating a snapshot needs at least one public key in " +
@@ -1514,8 +1513,8 @@ func (v *Vaultik) handleRemoveAllDryRun(
 
 // executeRemoveAll deletes every local snapshot and, unless LocalOnly
 // is set, every corresponding remote metadata directory plus any
-// orphan remote keys. Blobs are not touched. It returns an error when
-// any snapshot could not be removed.
+// orphan remote keys. Blobs are not touched; the printed prune-command
+// hint is the next step.
 func (v *Vaultik) executeRemoveAll(
 	localSnaps, orphanRemoteKeys []string, opts *RemoveOptions,
 ) (*RemoveResult, error) {
@@ -1529,11 +1528,18 @@ func (v *Vaultik) executeRemoveAll(
 
 	result := &RemoveResult{}
 
-	failures := v.removeAllLocalSnapshots(localSnaps, opts, result)
+	remoteErrors := v.removeAllLocalSnapshots(localSnaps, opts, result)
 
 	if !opts.LocalOnly {
-		failures += v.removeAllOrphanRemotes(orphanRemoteKeys, result)
-		result.RemoteRemoved = failures == 0
+		remoteErrors += v.removeAllOrphanRemotes(orphanRemoteKeys, result)
+
+		if remoteErrors == 0 {
+			result.RemoteRemoved = true
+		} else if v.UI != nil {
+			v.UI.Warningf("Some remote metadata deletions failed. Run '%s' "+
+				"once the remote is healthy to clean up unreferenced blobs.",
+				pruneCommandHint)
+		}
 	}
 
 	if v.SnapshotManager != nil {
@@ -1543,10 +1549,6 @@ func (v *Vaultik) executeRemoveAll(
 		}
 	}
 
-	if failures > 0 {
-		return result, fmt.Errorf("%d %w", failures, errSnapshotRemoveFailed)
-	}
-
 	if opts.JSON {
 		return result, v.outputRemoveJSON(result)
 	}
@@ -1555,6 +1557,9 @@ func (v *Vaultik) executeRemoveAll(
 
 	if !opts.LocalOnly && result.RemoteRemoved {
 		v.printlnStdout("Removed snapshot metadata from remote storage")
+		v.stdoutf("\nNote: Removed snapshots' blobs remain on the remote. "+
+			"Run '%s' to delete any blobs no longer referenced by any "+
+			"remaining remote snapshot.\n", pruneCommandHint)
 	}
 
 	return result, nil
@@ -1597,13 +1602,12 @@ func (v *Vaultik) deleteIncompleteSnapshot(snapshotIDStr string, id any) bool {
 }
 
 // removeAllLocalSnapshots removes each known local snapshot (and, unless
-// --local-only, its remote metadata), returning the number of snapshots
-// it could not remove. A snapshot left in the local index keeps its
-// remote metadata too, since it is not an orphan remote key.
+// --local-only, its remote metadata), returning the number of remote
+// deletion failures.
 func (v *Vaultik) removeAllLocalSnapshots(
 	localSnaps []string, opts *RemoveOptions, result *RemoveResult,
 ) int {
-	failures := 0
+	remoteErrors := 0
 
 	for _, snapshotID := range localSnaps {
 		log.Info("Removing snapshot", "snapshot_id", snapshotID)
@@ -1613,8 +1617,6 @@ func (v *Vaultik) removeAllLocalSnapshots(
 			log.Error("Failed to remove from local database",
 				"snapshot_id", snapshotID, "error", err)
 
-			failures++
-
 			continue
 		}
 
@@ -1625,14 +1627,14 @@ func (v *Vaultik) removeAllLocalSnapshots(
 				log.Warn("Failed to remove snapshot metadata from remote",
 					"snapshot_id", snapshotID, "error", err)
 
-				failures++
+				remoteErrors++
 			}
 		}
 
 		result.SnapshotsRemoved = append(result.SnapshotsRemoved, snapshotID)
 	}
 
-	return failures
+	return remoteErrors
 }
 
 // removeAllOrphanRemotes deletes remote snapshot metadata that has no