Accept a remote key for restore and verify, and document it (closes #124 )

A host restoring after the original is gone has no local index and cannot know a snapshot's human ID; `snapshot list` shows such snapshots only by their remote key. Restore and verify now resolve an identifier to that remote key: a human ID is hashed as before, and a remote key (or an unambiguous leading part of it, as the table prints) is used directly, resolved against the store's metadata listing. Deep verify reads the one snapshot in the exported database rather than filtering by the human ID. Adds an integration test that backs up with one index and hostname, then lists, restores, and deep-verifies from the store with a fresh empty index, a different hostname, and no age_recipients — comparing restored bytes to the source. The empty index is what makes it fail if restore ever needed the original one. Adds a "Restoring on another machine" README section walking the flow end to end, and drops the now-done roadmap item. Model: claude-opus-4-8
Reconcile the schema/migration docs with the code (closes #68 )
2026-09-21 20:00:22 +00:00 · 2026-09-21 21:58:37 +02:00
15 changed files with 426 additions and 467 deletions
@@ -104,7 +104,12 @@ Version: 2025-06-08
 13. Pre-1.0: NEVER write database migrations. There are no live databases
    anywhere — every user's local index can be rebuilt from a fresh full
-    backup. When the schema changes, just change `schema.sql` (and any code
+    backup. To change the schema, edit `internal/database/schema/001.sql`
-    that touches the affected tables). The local index is disposable until
+    (and any code that touches the affected tables) directly; do not add new
-    1.0 ships and is tagged.
+    numbered schema files. Those numbered files and the `schema_migrations`
    table they populate only bootstrap a fresh database — they are not an
    upgrade path. The local index is disposable until 1.0 ships and is
    tagged; once 1.0 is tagged that clause expires and the question of
    upgrading existing indexes returns. See [`docs/DATAMODEL.md`](docs/DATAMODEL.md)
    for the full explanation.
@@ -84,6 +84,57 @@ VAULTIK_AGE_SECRET_KEY='AGE-SECRET-KEY-...' vaultik snapshot restore <snapshot-i
 # 0 3 * * * vaultik snapshot create --cron --prune --keep-newer-than 4w
 ```
 ## restoring on another machine
 Restoring on a host that never ran the backup — a replacement machine
 after the original is gone — is the case vaultik is built for. That host
 needs only three things: the `vaultik` binary, the age **private** key,
 and the storage credentials for the destination. It does **not** need the
 local index, the original config file, or the original hostname.
 ```sh
 # install
 go install sneak.berlin/go/vaultik/cmd/vaultik@latest
 # create a config and point it at the ORIGINAL backup destination
 vaultik config init
 vaultik config set storage_url "s3://bucket/prefix?endpoint=https://s3.example.com"
 vaultik config set s3.access_key_id "..."
 vaultik config set s3.secret_access_key "..."
 # see what is on the destination store
 vaultik snapshot list
 ```
 `snapshot list` reads the destination store without the private key. A
 snapshot that is not in this host's (empty) local index is shown as
 remote-only: its row is identified by `<remote only:...>` rather than by
 a `hostname_name_timestamp` name, because the name lives only in the
 local index and the encrypted database and cannot be recovered from the
 store. Its timestamp and compressed size are real. (See the `snapshot
 list` description under [command details](#command-details) for the full
 explanation.)
 Use that remote key — the hex printed inside `<remote only:...>`, or the
 full `remote_key` from `snapshot list --json` — to restore and verify:
 ```sh
 # restore everything to /tmp/restored, then check every restored file's
 # chunk hashes
 VAULTIK_AGE_SECRET_KEY='AGE-SECRET-KEY-...' \
  vaultik snapshot restore --verify <remote-key> /tmp/restored
 # optionally, deep-verify the snapshot against the store (downloads and
 # cryptographically checks every blob)
 VAULTIK_AGE_SECRET_KEY='AGE-SECRET-KEY-...' \
  vaultik snapshot verify --deep <remote-key>
 ```
 `age_recipients` (the public key) is not needed to restore — only the
 private key in `VAULTIK_AGE_SECRET_KEY`. Both the abbreviated key printed
 in the table and the full 64-character key from `--json` are accepted; a
 leading part of the key is enough as long as it is unambiguous.
 ---
 ## cli
@@ -245,6 +296,8 @@ local index alone, and still exits zero.
 * Default (shallow): checks that all blobs referenced in the manifest exist in storage
 * `--deep`: Downloads and decrypts each blob, verifies chunk hashes against the
  encrypted metadata database
 * Accepts the same identifiers as `snapshot restore`: a snapshot ID, or a
  remote-only snapshot's remote key (or an unambiguous leading part of it)
 * `--json`: Output results as JSON
 **`snapshot purge`**: Remove old snapshots based on criteria. Retention is
@@ -275,6 +328,10 @@ on the destination in one go, use `vaultik remote nuke --force`.
 **`snapshot restore`**: Restore files from a backup snapshot.
 * Requires `VAULTIK_AGE_SECRET_KEY` environment variable
 * Accepts a snapshot ID, or — for a snapshot only on the destination
  store — its remote key (or an unambiguous leading part of it) as shown
  by `snapshot list`. See
  [restoring on another machine](#restoring-on-another-machine).
 * Optional path arguments to restore specific files/directories (default: all)
 * Preserves file permissions, timestamps, ownership (ownership requires root),
  symlinks, and empty directories
@@ -457,9 +514,13 @@ Key fields:
  sequentially. Restore speed is bound by single-stream throughput.
 * **Device nodes, named pipes, and sockets are silently skipped.** Only
  regular files, directories, and symlinks are backed up.
-* **No database migrations.** If the local SQLite schema changes between
+* **No upgrade path between versions.** There is no supported way to carry
-  versions, delete the local database (`vaultik database delete`) and run
+  an existing local index across a schema change; if the local SQLite
-  a full backup. Remote storage is unaffected.
+  schema changes between versions, delete the local database (`vaultik
  database delete`) and run a full backup. Remote storage is unaffected.
  (The binary does embed numbered schema files and a `schema_migrations`
  table to bootstrap a fresh database — see [`docs/DATAMODEL.md`](docs/DATAMODEL.md)
  — but that is not an upgrade path.)
 * **Files that change during backup may be inconsistent.** There is no
  filesystem snapshot or freeze. If a file is modified between the scan
  and chunk phases, the backed-up copy may reflect a partial write.
@@ -525,14 +586,12 @@ priority.
 ### infrastructure
-* **Cross-machine restore documentation.** The "restore from
+* **Cross-version schema upgrades.** There is no upgrade path between
-  another host" workflow works but isn't documented as a
+  released versions — pre-1.0 schema changes are handled by `vaultik
-  first-class operation in this README. Worth a dedicated section
+  database delete` plus a full re-scan (see
-  once it's settled.
+  [`docs/DATAMODEL.md`](docs/DATAMODEL.md)). Post-1.0 we'll need a
-* **Schema migrations.** Currently nonexistent — pre-1.0 schema
+  migration story to keep existing index databases usable across
-  changes are handled by `vaultik database delete` plus a full
+  upgrades.
  re-scan. Post-1.0 we'll need a migration story to keep existing
  index databases usable across upgrades.
 * **Storage backend coverage tests.** S3, file://, and rclone://
  all share the Storer interface but the rclone path is the least
  exercised in CI.
@@ -5,11 +5,30 @@
 Vaultik uses a local SQLite database to track file metadata, chunk mappings, and blob associations during the backup process. This database serves as an index for incremental backups and enables efficient deduplication.
 **Important Notes:**
- **No Migration Support (pre-1.0)**: Vaultik does not support database schema
+
-  migrations. The local index is treated as disposable — if the schema changes,
+This section is the authoritative explanation of the schema/migration story;
-  delete the local SQLite database (`vaultik database delete`) and run a full
+other documents (the README and `AGENTS.md`) link here.
-  backup. The remote storage is unaffected; the new index will re-deduplicate
+
-  against existing remote blobs.
+- **No upgrade path between versions (pre-1.0)**: Vaultik has no supported way to
  carry an existing local index across a schema change. The index is disposable
  — if the on-disk schema changes between versions, delete the local SQLite
  database (`vaultik database delete`) and run a full backup. Remote storage is
  unaffected; the new index re-deduplicates against existing remote blobs. This
  is the standing project policy, and it is separate from the schema bootstrap
  described next.
 - **Schema bootstrap**: a fresh database is populated from numbered SQL files
  embedded in the binary under `internal/database/schema/`. `000.sql` creates the
  `schema_migrations` table; `001.sql` creates the application tables. On opening
  a database the code applies each numbered file that has not yet run and records
  its version in `schema_migrations`. This bootstraps a new database; it does not
  upgrade an existing one between released versions.
 - **Changing the schema (pre-1.0)**: edit `internal/database/schema/001.sql` (and
  the code that touches the affected tables) directly. Do not add new numbered
  files — there is no installed base to migrate.
 - **Disposability expires at 1.0**: the index is treated as disposable only until
  1.0 ships and is tagged. Once 1.0 is tagged that clause expires and the
  question of upgrading existing indexes returns. It is deliberately left open
  here.
 - **Version Compatibility**: In rare cases, you may need to use the same version
  of Vaultik to restore a backup as was used to create it. This ensures
  compatibility with the metadata format stored in S3.
@@ -221,7 +221,10 @@ func newSnapshotVerifyCommand() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "verify <snapshot-id>",
 		Short: "Verify snapshot integrity",
-		Long:  "Verifies that all blobs referenced in a snapshot exist",
+		Long: "Verifies that all blobs referenced in a snapshot exist.\n\n" +
 			"The snapshot may be named by its ID or, on a host with no local\n" +
 			"index, by the remote key that 'snapshot list' prints for a\n" +
 			"remote-only snapshot (an unambiguous leading part is enough).",
 		Args: requireSnapshotIDArg,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			snapshotID := args[0]
@@ -48,6 +48,10 @@ target directory.
 If no paths are specified, all files are restored.
 If paths are specified, only matching files/directories are restored.
 The snapshot may be named by its ID or, when restoring on a host with no
 local index, by the remote key that 'snapshot list' prints for a
 remote-only snapshot (an unambiguous leading part is enough).
 Requires the VAULTIK_AGE_SECRET_KEY environment variable to be set with
 the age private key.
@@ -1,198 +0,0 @@
 package storage_test
 import (
 	"bytes"
 	"context"
 	"errors"
 	"io"
 	"reflect"
 	"sort"
 	"testing"
 	"sneak.berlin/go/vaultik/internal/storage"
 )
 // runStorerConformance is the shared Storer contract. Every backend that
 // can run in-process is expected to pass it: TestFileStorer runs it against
 // file://, TestS3Storer against s3://. A new backend inherits this coverage
 // by passing its own constructor, so the contract is defined once.
 //
 // It exercises the public Storer interface: round-trip, stat, list with
 // prefix filtering, overwrite, delete, delete-of-missing, and not-found on
 // Get and Stat. Each section takes its own fresh backend instance, so the
 // order of sections never matters and no section sees another's objects.
 func runStorerConformance(t *testing.T, newStorer func(*testing.T) storage.Storer) {
 	t.Helper()
 	conformanceRoundTrip(t, newStorer(t))
 	conformanceOverwrite(t, newStorer(t))
 	conformanceList(t, newStorer(t))
 	conformanceDelete(t, newStorer(t))
 	conformanceNotFound(t, newStorer(t))
 }
 // conformanceRoundTrip stores a nested key, then reads it back and stats it.
 func conformanceRoundTrip(t *testing.T, s storage.Storer) {
 	t.Helper()
 	ctx := context.Background()
 	key := "blobs/aa/bb/object.bin"
 	want := []byte("round-trip payload")
 	err := s.Put(ctx, key, bytes.NewReader(want))
 	if err != nil {
 		t.Fatalf("Put: %v", err)
 	}
 	got := getBytes(t, s, key)
 	if !bytes.Equal(got, want) {
 		t.Errorf("Get returned %q, want %q", got, want)
 	}
 	info, err := s.Stat(ctx, key)
 	if err != nil {
 		t.Fatalf("Stat: %v", err)
 	}
 	if info.Key != key {
 		t.Errorf("Stat key = %q, want %q", info.Key, key)
 	}
 	if info.Size != int64(len(want)) {
 		t.Errorf("Stat size = %d, want %d", info.Size, len(want))
 	}
 }
 // conformanceOverwrite checks that a second Put replaces the first.
 func conformanceOverwrite(t *testing.T, s storage.Storer) {
 	t.Helper()
 	ctx := context.Background()
 	key := "meta/snapshot.json"
 	err := s.Put(ctx, key, bytes.NewReader([]byte("first")))
 	if err != nil {
 		t.Fatalf("first Put: %v", err)
 	}
 	want := []byte("second and longer payload")
 	err = s.Put(ctx, key, bytes.NewReader(want))
 	if err != nil {
 		t.Fatalf("second Put: %v", err)
 	}
 	got := getBytes(t, s, key)
 	if !bytes.Equal(got, want) {
 		t.Errorf("after overwrite Get returned %q, want %q", got, want)
 	}
 }
 // conformanceList checks prefix filtering and the empty result for a
 // prefix that matches nothing.
 func conformanceList(t *testing.T, s storage.Storer) {
 	t.Helper()
 	ctx := context.Background()
 	keys := []string{"blobs/aa/one", "blobs/bb/two", "meta/three"}
 	for _, k := range keys {
 		err := s.Put(ctx, k, bytes.NewReader([]byte("data")))
 		if err != nil {
 			t.Fatalf("Put %q: %v", k, err)
 		}
 	}
 	if got := listSorted(t, s, ""); !reflect.DeepEqual(got, keys) {
 		t.Errorf("List(\"\") = %v, want %v", got, keys)
 	}
 	wantBlobs := []string{"blobs/aa/one", "blobs/bb/two"}
 	if got := listSorted(t, s, "blobs/"); !reflect.DeepEqual(got, wantBlobs) {
 		t.Errorf("List(\"blobs/\") = %v, want %v", got, wantBlobs)
 	}
 	if got := listSorted(t, s, "absent/"); len(got) != 0 {
 		t.Errorf("List(\"absent/\") = %v, want empty", got)
 	}
 }
 // conformanceDelete checks that Delete removes an object and that deleting
 // a missing key is not an error.
 func conformanceDelete(t *testing.T, s storage.Storer) {
 	t.Helper()
 	ctx := context.Background()
 	key := "blobs/cc/gone.bin"
 	err := s.Put(ctx, key, bytes.NewReader([]byte("temporary")))
 	if err != nil {
 		t.Fatalf("Put: %v", err)
 	}
 	err = s.Delete(ctx, key)
 	if err != nil {
 		t.Fatalf("Delete: %v", err)
 	}
 	_, err = s.Get(ctx, key)
 	if !errors.Is(err, storage.ErrNotFound) {
 		t.Errorf("Get after Delete error = %v, want ErrNotFound", err)
 	}
 	err = s.Delete(ctx, key)
 	if err != nil {
 		t.Errorf("Delete of missing key = %v, want nil", err)
 	}
 }
 // conformanceNotFound checks Get and Stat on an absent key.
 func conformanceNotFound(t *testing.T, s storage.Storer) {
 	t.Helper()
 	ctx := context.Background()
 	key := "never/written"
 	_, err := s.Get(ctx, key)
 	if !errors.Is(err, storage.ErrNotFound) {
 		t.Errorf("Get error = %v, want ErrNotFound", err)
 	}
 	_, err = s.Stat(ctx, key)
 	if !errors.Is(err, storage.ErrNotFound) {
 		t.Errorf("Stat error = %v, want ErrNotFound", err)
 	}
 }
 // getBytes reads a key fully and closes the reader.
 func getBytes(t *testing.T, s storage.Storer, key string) []byte {
 	t.Helper()
 	rc, err := s.Get(context.Background(), key)
 	if err != nil {
 		t.Fatalf("Get %q: %v", key, err)
 	}
 	defer func() { _ = rc.Close() }()
 	data, err := io.ReadAll(rc)
 	if err != nil {
 		t.Fatalf("read %q: %v", key, err)
 	}
 	return data
 }
 // listSorted returns the keys under a prefix in a stable order.
 func listSorted(t *testing.T, s storage.Storer, prefix string) []string {
 	t.Helper()
 	keys, err := s.List(context.Background(), prefix)
 	if err != nil {
 		t.Fatalf("List %q: %v", prefix, err)
 	}
 	sort.Strings(keys)
 	return keys
 }
@@ -1,27 +0,0 @@
 package storage_test
 import (
 	"testing"
 	"sneak.berlin/go/vaultik/internal/storage"
 )
 // newFileStorer builds a file:// backend rooted at a fresh temp directory.
 //
 //nolint:ireturn // conformance runs against the Storer interface by design
 func newFileStorer(t *testing.T) storage.Storer {
 	t.Helper()
 	s, err := storage.NewFileStorer(t.TempDir())
 	if err != nil {
 		t.Fatalf("NewFileStorer: %v", err)
 	}
 	return s
 }
 // TestFileStorer runs the shared Storer contract against the file:// backend.
 func TestFileStorer(t *testing.T) {
 	t.Parallel()
 	runStorerConformance(t, newFileStorer)
 }
@@ -1,58 +0,0 @@
 package storage_test
 import (
 	"context"
 	"errors"
 	"testing"
 	"sneak.berlin/go/vaultik/internal/storage"
 )
 // The rclone backend is a thin adapter over the rclone library: it turns a
 // (remote, path) pair into rclone's "remote:path" string, hands it to
 // rclone, and maps rclone's own results back to the Storer interface. What
 // can be tested in-process, without a configured remote or network, is that
 // adapter layer — how the arguments are shaped and how construction errors
 // are reported. The data-plane operations (Put/Get/List/Delete) are rclone's
 // own, exercised against a real provider (drive, s3-via-rclone, ...), which
 // needs a configured remote with credentials and network access and so is
 // out of reach of a unit test. The shared Storer conformance suite therefore
 // runs against the in-process file and s3 backends; the rclone backend
 // inherits that contract once a remote is configured.
 //
 // These tests use rclone's ":local:" on-the-fly backend, which addresses the
 // local filesystem directly without any configured remote, so construction
 // runs entirely in-process.
 // TestNewRcloneStorerConstruction checks that a valid remote constructs a
 // backend and that Info() reports the shaped "remote:path" location.
 //
 //nolint:paralleltest // NewRcloneStorer installs the process-global rclone config
 func TestNewRcloneStorerConstruction(t *testing.T) {
 	dir := t.TempDir()
 	s, err := storage.NewRcloneStorer(context.Background(), ":local", dir)
 	if err != nil {
 		t.Fatalf("NewRcloneStorer: %v", err)
 	}
 	// Info().Location is the "remote:path" string the adapter builds from
 	// its two arguments, so asserting it confirms the argument shaping.
 	want := ":local:" + dir
 	if got := s.Info().Location; got != want {
 		t.Errorf("Info().Location = %q, want %q", got, want)
 	}
 }
 // TestNewRcloneStorerUnknownRemote checks that a remote that is not in the
 // rclone config fails construction with the ErrRemoteNotFound sentinel,
 // rather than silently returning a backend pointed nowhere.
 //
 //nolint:paralleltest // NewRcloneStorer installs the process-global rclone config
 func TestNewRcloneStorerUnknownRemote(t *testing.T) {
 	_, err := storage.NewRcloneStorer(
 		context.Background(), "vaultik-no-such-remote", "path")
 	if !errors.Is(err, storage.ErrRemoteNotFound) {
 		t.Errorf("NewRcloneStorer error = %v, want ErrRemoteNotFound", err)
 	}
 }
@@ -13,23 +13,18 @@ import (
 	"sneak.berlin/go/vaultik/internal/storage"
 )
-// s3TestBucket is the bucket created for each in-process S3 server.
+// TestS3StorerMissingKeyMapsToErrNotFound verifies that the s3 backend reports
-const s3TestBucket = "test-bucket"
+// a missing object as storage.ErrNotFound, matching the file and rclone
-
+// backends and the Storer contract. Without the mapping, Get and Stat leak the
-// newS3Storer builds an s3:// backend backed by a fresh in-process
+// raw SDK error and errors.Is(err, storage.ErrNotFound) is false.
 // S3 server. It reuses the same in-memory S3 harness (gofakes3 + s3mem
 // over httptest) that internal/s3 and the not-found regression test use,
 // so no new mock or dependency is introduced. Each call gets its own
 // server, bucket, and client, so the conformance suite's per-section
 // instances stay isolated.
 //
-//nolint:ireturn // conformance runs against the Storer interface by design
+//nolint:paralleltest // shares an in-process S3 server via t.Cleanup
-func newS3Storer(t *testing.T) storage.Storer {
+func TestS3StorerMissingKeyMapsToErrNotFound(t *testing.T) {
-	t.Helper()
+	const bucket = "test-bucket"
 	backend := s3mem.New()
-	err := backend.CreateBucket(s3TestBucket)
+	err := backend.CreateBucket(bucket)
 	if err != nil {
 		t.Fatalf("create bucket: %v", err)
 	}
@@ -37,9 +32,11 @@ func newS3Storer(t *testing.T) storage.Storer {
 	srv := httptest.NewServer(gofakes3.New(backend).Server())
 	t.Cleanup(srv.Close)
-	client, err := s3.NewClient(context.Background(), s3.Config{
+	ctx := context.Background()
 	client, err := s3.NewClient(ctx, s3.Config{
 		Endpoint:        srv.URL,
-		Bucket:          s3TestBucket,
+		Bucket:          bucket,
 		AccessKeyID:     "test",
 		SecretAccessKey: "test",
 		Region:          "us-east-1",
@@ -48,28 +45,9 @@ func newS3Storer(t *testing.T) storage.Storer {
 		t.Fatalf("new client: %v", err)
 	}
-	return storage.NewS3Storer(client)
+	storer := storage.NewS3Storer(client)
 }
-// TestS3Storer runs the shared Storer contract against the s3:// backend,
+	_, err = storer.Get(ctx, "does-not-exist")
 // so it is held to the same round-trip, list, delete, and not-found
 // behaviour as the file:// backend.
 func TestS3Storer(t *testing.T) {
 	t.Parallel()
 	runStorerConformance(t, newS3Storer)
 }
 // TestS3StorerMissingKeyMapsToErrNotFound pins the specific contract that a
 // missing object surfaces as storage.ErrNotFound rather than the raw AWS SDK
 // error. Without the mapping, errors.Is(err, storage.ErrNotFound) is false on
 // s3 and callers would branch differently per backend.
 func TestS3StorerMissingKeyMapsToErrNotFound(t *testing.T) {
 	t.Parallel()
 	storer := newS3Storer(t)
 	ctx := context.Background()
 	_, err := storer.Get(ctx, "does-not-exist")
 	if !errors.Is(err, storage.ErrNotFound) {
 		t.Errorf("Get on missing key: got %v, want ErrNotFound", err)
 	}
@@ -1,110 +0,0 @@
 package storage_test
 import (
 	"errors"
 	"reflect"
 	"testing"
 	"sneak.berlin/go/vaultik/internal/storage"
 )
 // TestParseStorageURLValid checks that each supported scheme parses into
 // the expected fields, since those fields decide which backend is built.
 func TestParseStorageURLValid(t *testing.T) {
 	t.Parallel()
 	const bucket = "mybucket"
 	cases := []struct {
 		name string
 		raw  string
 		want *storage.URL
 	}{
 		{
 			name: "file absolute path",
 			raw:  "file:///var/backups/vaultik",
 			want: &storage.URL{Scheme: "file", Prefix: "/var/backups/vaultik"},
 		},
 		{
 			name: "s3 bucket and prefix, ssl defaults on",
 			raw:  "s3://mybucket/backups/host",
 			want: &storage.URL{
 				Scheme: "s3", Bucket: bucket,
 				Prefix: "backups/host", UseSSL: true,
 			},
 		},
 		{
 			name: "s3 bucket only",
 			raw:  "s3://mybucket",
 			want: &storage.URL{Scheme: "s3", Bucket: bucket, UseSSL: true},
 		},
 		{
 			name: "s3 with endpoint, region, ssl off",
 			raw:  "s3://mybucket?endpoint=minio.example.com&region=us-west-2&ssl=false",
 			want: &storage.URL{
 				Scheme: "s3", Bucket: bucket,
 				Endpoint: "minio.example.com", Region: "us-west-2", UseSSL: false,
 			},
 		},
 		{
 			name: "rclone remote and path",
 			raw:  "rclone://gdrive/backups/host",
 			want: &storage.URL{
 				Scheme: "rclone", RcloneRemote: "gdrive", Prefix: "backups/host",
 			},
 		},
 		{
 			name: "rclone remote only",
 			raw:  "rclone://gdrive",
 			want: &storage.URL{Scheme: "rclone", RcloneRemote: "gdrive"},
 		},
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {
 			t.Parallel()
 			got, err := storage.ParseStorageURL(tc.raw)
 			if err != nil {
 				t.Fatalf("ParseStorageURL(%q) returned error: %v", tc.raw, err)
 			}
 			if !reflect.DeepEqual(got, tc.want) {
 				t.Errorf("ParseStorageURL(%q) = %+v, want %+v", tc.raw, got, tc.want)
 			}
 		})
 	}
 }
 // TestParseStorageURLErrors checks that empty, missing, and unknown-scheme
 // inputs fail with the documented sentinel errors instead of parsing to a
 // wrong destination.
 func TestParseStorageURLErrors(t *testing.T) {
 	t.Parallel()
 	cases := []struct {
 		name    string
 		raw     string
 		wantErr error
 	}{
 		{"empty url", "", storage.ErrEmptyStorageURL},
 		{"file empty path", "file://", storage.ErrEmptyFilePath},
 		{"s3 missing bucket", "s3://", storage.ErrMissingBucket},
 		{"s3 missing bucket with path", "s3:///justprefix", storage.ErrMissingBucket},
 		{"rclone missing remote", "rclone://", storage.ErrMissingRemote},
 		{"unknown scheme", "gs://bucket/x", storage.ErrUnsupportedScheme},
 		{"no scheme", "/local/path", storage.ErrUnsupportedScheme},
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {
 			t.Parallel()
 			_, err := storage.ParseStorageURL(tc.raw)
 			if !errors.Is(err, tc.wantErr) {
 				t.Errorf("ParseStorageURL(%q) error = %v, want %v",
 					tc.raw, err, tc.wantErr)
 			}
 		})
 	}
 }
@@ -18,7 +18,6 @@ import (
 	"sneak.berlin/go/vaultik/internal/blobgen"
 	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/log"
 	"sneak.berlin/go/vaultik/internal/snapshot"
 	"sneak.berlin/go/vaultik/internal/types"
 )
@@ -577,14 +576,20 @@ func (v *Vaultik) handleRestoreVerification(
 }
 // downloadSnapshotDB downloads and decrypts the snapshot metadata
-// database. The snapshotID is the human ID; we hash it to the remote
+// database. The identifier is resolved to the snapshot's remote key: a
-// key for the storage path.
+// human ID is hashed, and a remote key (or its abbreviation, as printed
 // for a remote-only snapshot) is used as-is, so a host with no local
 // index can restore the snapshots it can only see on the store.
 func (v *Vaultik) downloadSnapshotDB(
 	snapshotID string, identity age.Identity,
 ) (*database.DB, error) {
 	remoteKey, err := v.resolveSnapshotRemoteKey(snapshotID)
 	if err != nil {
 		return nil, err
 	}
 	// Download encrypted database from storage
-	dbKey := fmt.Sprintf("metadata/%s/db.zst.age",
+	dbKey := fmt.Sprintf("metadata/%s/db.zst.age", remoteKey)
 		snapshot.RemoteSnapshotKey(snapshotID))
 	reader, err := v.Storage.Get(v.ctx, dbKey)
 	if err != nil {
@@ -0,0 +1,167 @@
 package vaultik_test
 import (
 	"bytes"
 	"context"
 	"io"
 	"path/filepath"
 	"testing"
 	"github.com/spf13/afero"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"sneak.berlin/go/vaultik/internal/config"
 	"sneak.berlin/go/vaultik/internal/database"
 	"sneak.berlin/go/vaultik/internal/log"
 	"sneak.berlin/go/vaultik/internal/snapshot"
 	"sneak.berlin/go/vaultik/internal/storage"
 	"sneak.berlin/go/vaultik/internal/ui"
 	"sneak.berlin/go/vaultik/internal/vaultik"
 )
 // TestRestoreOnAnotherMachine proves the disaster-recovery path: a host
 // that has only the vaultik binary, the age secret key, and the storage
 // credentials — no local index, a different hostname, and no
 // age_recipients configured — can list, restore, and verify a snapshot
 // straight from the destination store.
 //
 // The backup half writes a snapshot with one index and hostname. The
 // restore half throws that index away entirely: a fresh, empty index and
 // a config that shares nothing with the original but the storage location
 // and the secret key. If restore or verify needed the original local
 // index — or the human snapshot ID that only that index holds — this test
 // could not run, because the recovery host can know neither.
 func TestRestoreOnAnotherMachine(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")
 	restoreDir := filepath.Join(tempDir, "restored")
 	dbPath := filepath.Join(tempDir, "index.sqlite")
 	chunkSize := int64(64 * 1024)
 	maxBlobSize := int64(512 * 1024)
 	sourceFiles := writeRecoverySourceTree(t, fs, dataDir, chunkSize)
 	ctx := context.Background()
 	// Backup host: one index, hostname test-host, age_recipients set.
 	// runFileStorageBackup closes the index before returning, so nothing
 	// below can lean on it.
 	_, storer, originalID := runFileStorageBackup(
 		ctx, t, fs, dataDir, storeDir, dbPath, chunkSize, maxBlobSize)
 	// Recovery host: a fresh empty index, a different hostname, and no
 	// age_recipients — only the secret key and the same storage location.
 	recovery, stdout := newRecoveryHost(ctx, t, fs, storer)
 	// The recovery index really is empty. This is the assertion that makes
 	// the test a guard against restore quietly depending on the original
 	// index: if it did, an empty index would make restore fail.
 	localSnaps, err := recovery.Repositories.Snapshots.ListRecent(ctx, 100)
 	require.NoError(t, err)
 	require.Empty(t, localSnaps, "recovery host must start with no local index")
 	// List: the snapshot shows up as remote-only, identified by its remote
 	// key, with no recoverable human ID.
 	require.NoError(t, recovery.ListSnapshots(true))
 	rows := decodeListJSON(t, stdout.String())
 	require.Len(t, rows, 1)
 	remote := rows[0]
 	assert.False(t, remote.LocallyTracked, "snapshot must be remote-only here")
 	assert.Empty(t, remote.ID, "the human ID is unknown to the recovery host")
 	require.Len(t, remote.RemoteKey, 64)
 	assert.Equal(t, snapshot.RemoteSnapshotKey(originalID), remote.RemoteKey,
 		"the listed key is the hashed snapshot ID")
 	// Restore driven by the abbreviated identifier the table prints (the
 	// first 12 hex of the remote key), then deep-verify from the store
 	// keyed by the full remote key. Both are what a recovery host can know.
 	require.NoError(t, recovery.Restore(&vaultik.RestoreOptions{
 		SnapshotID: remote.RemoteKey[:12],
 		TargetDir:  restoreDir,
 		Verify:     true,
 	}))
 	require.NoError(t, recovery.RunDeepVerify(
 		remote.RemoteKey, &vaultik.VerifyOptions{Deep: true}))
 	assertRestoredTreeMatches(t, fs, restoreDir, sourceFiles)
 }
 // writeRecoverySourceTree writes a small source tree spanning several
 // chunks (so restore reassembles real multi-chunk files) and returns the
 // content keyed by absolute path.
 func writeRecoverySourceTree(
 	t *testing.T, fs afero.Fs, dataDir string, chunkSize int64,
 ) map[string][]byte {
 	t.Helper()
 	sourceFiles := map[string][]byte{
 		filepath.Join(dataDir, "notes.txt"):        []byte("recover me"),
 		filepath.Join(dataDir, "sub", "big.bin"):   bytesPattern("big-", int(chunkSize*3)),
 		filepath.Join(dataDir, "sub", "small.bin"): bytesPattern("small-", 128),
 	}
 	for path, content := range sourceFiles {
 		require.NoError(t, fs.MkdirAll(filepath.Dir(path), 0o755))
 		require.NoError(t, afero.WriteFile(fs, path, content, 0o644))
 	}
 	return sourceFiles
 }
 // newRecoveryHost builds the Vaultik a replacement machine would run: an
 // empty in-memory index, a hostname different from the backup host, no
 // age_recipients, and only the secret key plus the shared storer. It
 // returns the instance and the buffer its stdout is wired to.
 func newRecoveryHost(
 	ctx context.Context, t *testing.T, fs afero.Fs, storer storage.Storer,
 ) (*vaultik.Vaultik, *bytes.Buffer) {
 	t.Helper()
 	recoveryDB, err := database.New(ctx, ":memory:")
 	require.NoError(t, err)
 	t.Cleanup(func() { _ = recoveryDB.Close() })
 	stdout := &bytes.Buffer{}
 	recovery := &vaultik.Vaultik{
 		Config: &config.Config{
 			AgeSecretKey: testAgeSecretKey,
 			Hostname:     "recovery-host",
 		},
 		Storage:      storer,
 		Fs:           fs,
 		Repositories: database.NewRepositories(recoveryDB),
 		DB:           recoveryDB,
 		Stdout:       stdout,
 		Stderr:       io.Discard,
 		UI:           ui.NewWithColor(io.Discard, false),
 	}
 	recovery.SetContext(ctx)
 	return recovery, stdout
 }
 // assertRestoredTreeMatches byte-compares every restored file against its
 // source content.
 func assertRestoredTreeMatches(
 	t *testing.T, fs afero.Fs, restoreDir string, sourceFiles map[string][]byte,
 ) {
 	t.Helper()
 	for origPath, expected := range sourceFiles {
 		restored := filepath.Join(restoreDir, origPath)
 		got, err := afero.ReadFile(fs, restored)
 		require.NoErrorf(t, err, "restored file missing: %s", restored)
 		require.Truef(t, bytes.Equal(got, expected),
 			"byte mismatch for %s", origPath)
 	}
 }
@@ -670,9 +670,11 @@ func (v *Vaultik) VerifySnapshotWithOptions(
 	v.printVerifyHeader(snapshotID, opts)
-	// Download and parse manifest. The caller supplies a human
+	// Resolve the identifier to the snapshot's remote key and download the
-	// snapshot ID; we hash it to address remote storage.
+	// manifest. A human ID is hashed; a remote key (or its abbreviation,
-	manifest, err := v.downloadManifestByKey(snapshot.RemoteSnapshotKey(snapshotID))
+	// as printed for a remote-only snapshot) is used as-is, so a host with
 	// no local index can verify a snapshot it can only see on the store.
 	manifest, err := v.resolveAndDownloadManifest(snapshotID)
 	if err != nil {
 		if opts.JSON {
 			result.Status = verifyStatusFailed
@@ -0,0 +1,101 @@
 package vaultik
 import (
 	"errors"
 	"fmt"
 	"strings"
 	"sneak.berlin/go/vaultik/internal/snapshot"
 )
 // remoteKeyHexLen is the length of a full remote snapshot key: a SHA256
 // digest rendered as lowercase hex.
 const remoteKeyHexLen = 64
 // Sentinel errors for resolving a snapshot identifier against the store.
 var (
 	errSnapshotKeyNotFound = errors.New(
 		"no snapshot on the destination store matches this identifier")
 	errSnapshotKeyAmbiguous = errors.New(
 		"identifier matches more than one snapshot on the destination store")
 )
 // resolveSnapshotRemoteKey turns a snapshot identifier supplied on the
 // command line into the remote key that names the snapshot's metadata
 // directory on the destination store. Every remote path a restore or
 // verify reads is built from that key.
 //
 // Two forms are accepted, matching the two things a host can know:
 //
 //   - A human snapshot ID (hostname_name_timestamp), which a host holding
 //     the local index has. It is hashed to its remote key; the store is
 //     not consulted.
 //   - A remote key, or the leading part of one, which is all a host with
 //     no local index can know — it is exactly what `snapshot list` prints
 //     for a remote-only snapshot (see formatRemoteOnlyID). It is resolved
 //     against the destination store's metadata listing; an identifier that
 //     matches no snapshot, or more than one, is an error.
 //
 // The two are told apart by shape: a remote key is lowercase hex, and a
 // human snapshot ID never is (it carries a hostname, underscores, and an
 // RFC3339 timestamp).
 func (v *Vaultik) resolveSnapshotRemoteKey(identifier string) (string, error) {
 	if !isRemoteKeyOrPrefix(identifier) {
 		return snapshot.RemoteSnapshotKey(identifier), nil
 	}
 	keys, err := v.listAllRemoteSnapshotKeys()
 	if err != nil {
 		return "", fmt.Errorf(
 			"listing destination store to resolve %q: %w", identifier, err)
 	}
 	var matches []string
 	for _, key := range keys {
 		if strings.HasPrefix(key, identifier) {
 			matches = append(matches, key)
 		}
 	}
 	switch len(matches) {
 	case 1:
 		return matches[0], nil
 	case 0:
 		return "", fmt.Errorf("%w: %s", errSnapshotKeyNotFound, identifier)
 	default:
 		return "", fmt.Errorf("%w: %s (%d matches)",
 			errSnapshotKeyAmbiguous, identifier, len(matches))
 	}
 }
 // resolveAndDownloadManifest resolves a snapshot identifier to its remote
 // key (see resolveSnapshotRemoteKey) and downloads that snapshot's
 // manifest.
 func (v *Vaultik) resolveAndDownloadManifest(
 	identifier string,
 ) (*snapshot.Manifest, error) {
 	remoteKey, err := v.resolveSnapshotRemoteKey(identifier)
 	if err != nil {
 		return nil, err
 	}
 	return v.downloadManifestByKey(remoteKey)
 }
 // isRemoteKeyOrPrefix reports whether s is a full remote key or the
 // leading part of one: 1 to 64 lowercase hex characters. A human snapshot
 // ID is never all hex, so this shape test is enough to tell the two apart.
 func isRemoteKeyOrPrefix(s string) bool {
 	if s == "" || len(s) > remoteKeyHexLen {
 		return false
 	}
 	for _, r := range s {
 		if (r < '0' || r > '9') && (r < 'a' || r > 'f') {
 			return false
 		}
 	}
 	return true
 }
@@ -138,8 +138,15 @@ func (v *Vaultik) RunDeepVerify(snapshotID string, opts *VerifyOptions) error {
 func (v *Vaultik) loadVerificationData(
 	snapshotID string, opts *VerifyOptions, result *VerifyResult,
 ) (*snapshot.Manifest, *tempDB, []snapshot.BlobInfo, error) {
-	// All remote paths use the hashed key derived from the human ID.
+	// Resolve the identifier to the snapshot's remote key. A human ID is
-	remoteKey := snapshot.RemoteSnapshotKey(snapshotID)
+	// hashed; a remote key (or its abbreviation, as printed for a
 	// remote-only snapshot) is used as-is, so a host with no local index
 	// can verify a snapshot it can only see on the store.
 	remoteKey, err := v.resolveSnapshotRemoteKey(snapshotID)
 	if err != nil {
 		return nil, nil, nil, v.deepVerifyFailure(result, opts,
 			fmt.Sprintf("resolving snapshot identifier: %v", err), err)
 	}
 	// Download manifest. downloadManifestByKey is the single reader for
 	// remote manifests; see its doc comment.
@@ -186,7 +193,7 @@ func (v *Vaultik) loadVerificationData(
 			fmt.Errorf("failed to decrypt database: %w", err))
 	}
-	dbBlobs, err := v.getBlobsFromDatabase(snapshotID, tdb.DB)
+	dbBlobs, err := v.getBlobsFromDatabase(tdb.DB)
 	if err != nil {
 		_ = tdb.Close()
@@ -501,19 +508,21 @@ func (v *Vaultik) verifyBlobFinalIntegrity(
 	return nil
 }
-// getBlobsFromDatabase gets all blobs for the snapshot from the database
+// getBlobsFromDatabase gets all blobs for the snapshot from the database.
-func (v *Vaultik) getBlobsFromDatabase(
+//
-	snapshotID string, db *sql.DB,
+// The exported per-snapshot database holds exactly one snapshot's data
-) ([]snapshot.BlobInfo, error) {
+// (see cleanSnapshotDB), so every row in snapshot_blobs belongs to it.
 // We select them directly rather than filtering by the human snapshot ID,
 // which a host restoring from the store alone does not have.
 func (v *Vaultik) getBlobsFromDatabase(db *sql.DB) ([]snapshot.BlobInfo, error) {
 	query := `
 		SELECT b.blob_hash, b.compressed_size
 		FROM snapshot_blobs sb
 		JOIN blobs b ON sb.blob_hash = b.blob_hash
 		WHERE sb.snapshot_id = ?
 		ORDER BY b.blob_hash
 	`
-	rows, err := db.QueryContext(v.ctx, query, snapshotID)
+	rows, err := db.QueryContext(v.ctx, query)
 	if err != nil {
 		return nil, fmt.Errorf("failed to query snapshot blobs: %w", err)
 	}