Bind the local index to the s3.* destination too (closes #298)

The local index was bound to its destination only through storage_url.
With the s3.* form nothing was checked, so after s3.bucket or s3.prefix
changed the next backup treated every chunk as already stored, uploaded
nothing, and completed a snapshot that could not be restored.

Without storage_url, the binding now records the destination the s3.*
fields name, written as an s3:// URL from s3.endpoint, s3.bucket and
s3.prefix, and a change is refused with the same error and advice. The
advice line now names the s3.* fields as well as storage_url.

Judgement call: the fields are compared as written, so an equivalent
spelling (a trailing slash on the prefix, a scheme on the endpoint) is
also refused, as it already is for storage_url.

Model: opus-5-5

README.md

@@ -382,12 +382,10 @@ 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.
@@ -407,15 +405,15 @@ 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
 entirely. Remote storage is unaffected; the next backup will do a full
 scan and re-deduplicate against existing remote blobs, and the local
 index will re-bind to the currently configured storage destination.
-Use this after changing `storage_url` to a different destination.
+Use this after changing `storage_url`, or `s3.endpoint`, `s3.bucket` or
+`s3.prefix`, to a different destination.
 * `--force`: Skip confirmation prompt
 
 ---

TODO.md

@@ -22,16 +22,24 @@ the tag exists and is exercised; what is left is merging `next` to
 
 # Completed Steps
 
-- 2026-10-12: 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.
+- 2026-10-12: Bound the local index to the destination an `s3.*` config
+  names ([issue #298](https://git.eeqj.de/sneak/vaultik/issues/298)).
+  Only `storage_url` was checked, so after `s3.bucket` or `s3.prefix`
+  changed, the next backup treated every chunk as already stored,
+  uploaded nothing, and completed a snapshot that could not be restored.
+  Without `storage_url`, the local index is now bound to `s3.endpoint`,
+  `s3.bucket` and `s3.prefix`, and a change is refused as a changed
+  `storage_url` is.
+
+- 2026-10-12: Rejected a retention duration longer than about 292 years
+  ([issue #289](https://git.eeqj.de/sneak/vaultik/issues/289)). The
+  number given to `--older-than` or `--keep-newer-than` was multiplied
+  by the length of its unit with no limit, so from `293y`, `15251w`,
+  `3559mo` or `106752d`, or a sum of parts such as `200y200y`, the
+  result wrapped to a negative duration. The cutoff then lay in the
+  future, every snapshot of the name was deleted, the one just made
+  included, and the command exited 0. Such a duration is now rejected
+  as invalid and nothing is deleted.
 
 - 2026-10-08: Made a backup cancelled under `--skip-errors` stop at once
   ([issue #286](https://git.eeqj.de/sneak/vaultik/issues/286)). After

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/helpers.go

@@ -3,6 +3,7 @@ package vaultik
 import (
 	"errors"
 	"fmt"
+	"math"
 	"regexp"
 	"strconv"
 	"strings"
@@ -47,6 +48,10 @@ const (
 	year  = 365 * day
 )
 
+// maxDuration is the largest value a time.Duration can hold, about 292
+// years.
+const maxDuration = time.Duration(math.MaxInt64)
+
 // A snapshot ID split on "_" has at least a hostname and a trailing
 // timestamp.
 const minSnapshotIDParts = 2
@@ -145,10 +150,10 @@ func parseSnapshotName(snapshotID, hostname string) string {
 // parseDuration parses a duration string with support for human-friendly units:
 // d/day/days, w/week/weeks, mo/month/months, y/year/years, plus standard Go
 // duration units. Following Go, m is minutes and mo is months. A bare number,
-// an unknown unit, and a negative value are all rejected. Outside the Go
-// units the input must be whole numbers each followed directly by a unit
-// (2w3d), so 1.0y and 30 days are errors; decimals work only in Go units
-// (1.5h).
+// an unknown unit, a negative value, and a total longer than maxDuration are
+// all rejected. Outside the Go units the input must be whole numbers each
+// followed directly by a unit (2w3d), so 1.0y and 30 days are errors;
+// decimals work only in Go units (1.5h).
 func parseDuration(s string) (time.Duration, error) {
 	if strings.HasPrefix(strings.TrimSpace(s), "-") {
 		return 0, errNegativeDuration
@@ -181,19 +186,30 @@ func parseDuration(s string) (time.Duration, error) {
 			return 0, fmt.Errorf("invalid number %q: %w", match[1], err)
 		}
 
+		var unitLength time.Duration
+
 		unit := strings.ToLower(match[2])
 		switch unit {
 		case "d", "day", "days":
-			total += time.Duration(n) * day
+			unitLength = day
 		case "w", "week", "weeks":
-			total += time.Duration(n) * week
+			unitLength = week
 		case "mo", "month", "months":
-			total += time.Duration(n) * month
+			unitLength = month
 		case "y", "year", "years":
-			total += time.Duration(n) * year
+			unitLength = year
 		default:
 			return 0, fmt.Errorf("%w %q", errUnknownTimeUnit, unit)
 		}
+
+		// Past maxDuration the sum wraps to a negative value, which would
+		// put the purge cutoff in the future.
+		if time.Duration(n) > (maxDuration-total)/unitLength {
+			return 0, fmt.Errorf("%w: %q is longer than about 292 years",
+				errInvalidDuration, s)
+		}
+
+		total += time.Duration(n) * unitLength
 	}
 
 	return total, nil

internal/vaultik/helpers_test.go

@@ -111,6 +111,17 @@ func TestParseDuration(t *testing.T) {
 		{"30 days", 0, true},
 		{"30 days ago", 0, true},
 		{"x7d", 0, true},
+		// The largest time.Duration is about 292 years. A larger value
+		// must be rejected, not wrapped to a negative one, which would
+		// put the cutoff in the future and select every snapshot.
+		{"292y", 292 * 365 * 24 * time.Hour, false},
+		{"293y", 0, true},
+		{"3559mo", 0, true},
+		{"15251w", 0, true},
+		{"106752d", 0, true},
+		{"2562048h", 0, true},
+		{"200y200y", 0, true},
+		{"292y6mo", 0, true},
 	}
 
 	for _, tt := range tests {

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)
@@ -63,62 +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")
-		})
-	}
-}
-
-// 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"
@@ -43,22 +35,6 @@ func (v *Vaultik) NukeRemote(force bool) error {
 		return errNukeRequiresForce
 	}
 
-	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})
@@ -82,6 +58,8 @@ func (v *Vaultik) emptyDestinationStore() error {
 		}
 	}
 
+	v.UI.Completef("Backup destination store is now empty.")
+
 	return nil
 }
 
@@ -184,17 +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.Error(t, err, "the prune step must fail the run")
-	assert.FileExists(t, orphan)
-}

internal/vaultik/purge_per_name_test.go

@@ -267,6 +267,29 @@ func TestPurgeOlderThan_WithNameFilter(t *testing.T) {
 	assert.Contains(t, remaining, snapHomeT0)
 }
 
+func TestPurgeOlderThan_TooLargeDeletesNothing(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	snapshotIDs := []string{snapHomeT0, snapHomeT1}
+
+	v := setupPurgeTest(t, snapHostname, snapshotIDs)
+
+	err := v.PurgeSnapshotsWithOptions(&vaultik.SnapshotPurgeOptions{
+		OlderThan: "1000y",
+		Force:     true,
+	})
+	require.Error(t, err)
+
+	err = v.PurgeSnapshotsWithOptions(&vaultik.SnapshotPurgeOptions{
+		OlderThan: "292y",
+		Force:     true,
+	})
+	require.NoError(t, err)
+
+	assert.ElementsMatch(t, snapshotIDs, listRemainingSnapshots(t, v))
+}
+
 func TestPurgeKeepLatest_ThreeNames(t *testing.T) {
 	log.Initialize(log.Config{})
 	t.Parallel()

internal/vaultik/remove_snapshot_test.go

@@ -361,8 +361,7 @@ 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/snapshot.go

@@ -23,7 +23,6 @@ var (
 	errNoSnapshotsInConfig  = errors.New("no snapshots configured")
 	errSnapshotVerifyFailed = errors.New("verification failed")
 	errRemoveAllNeedsForce  = errors.New("--all requires --force")
-	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 " +
@@ -1465,8 +1464,8 @@ 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) {
@@ -1480,11 +1479,18 @@ 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 {
@@ -1494,10 +1500,6 @@ func (v *Vaultik) executeRemoveAll(
 		}
 	}
 
-	if failures > 0 {
-		return result, fmt.Errorf("%d %w", failures, errSnapshotRemoveFailed)
-	}
-
 	if opts.JSON {
 		return result, v.outputRemoveJSON(result)
 	}
@@ -1506,6 +1508,9 @@ 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
@@ -1548,13 +1553,12 @@ 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)
@@ -1564,8 +1568,6 @@ func (v *Vaultik) removeAllLocalSnapshots(
 			log.Error("Failed to remove from local database",
 				"snapshot_id", snapshotID, "error", err)
 
-			failures++
-
 			continue
 		}
 
@@ -1576,14 +1578,14 @@ 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

internal/vaultik/storage_bind.go

@@ -9,7 +9,7 @@ import (
 )
 
 // errStorageBindingMismatch is returned when the local index database is
-// bound to a different destination than the configured storage_url.
+// bound to a different destination than the configured one.
 var errStorageBindingMismatch = errors.New(
 	"local index is bound to a different backup destination")
 
@@ -24,8 +24,9 @@ var errStorageBindingMismatch = errors.New(
 //
 // Behaviour:
 //   - On first use (empty stored value), record the configured
-//     storage_url and log the binding.
-//   - When the stored value matches the configured storage_url, do
+//     destination (storage_url, or the s3.* endpoint, bucket and
+//     prefix) and log the binding.
+//   - When the stored value matches the configured destination, do
 //     nothing and return nil.
 //   - When the two differ, refuse with an error that tells the user
 //     how to recover (revert the config, or run `vaultik database
@@ -46,12 +47,10 @@ func (v *Vaultik) EnsureStorageBinding() error {
 
 	configured := v.Config.StorageURL
 	if configured == "" {
-		// Some legacy configs still use the split s3.* keys instead of
-		// storage_url. Falling back to a synthetic URL for those would
-		// hide the fact that the binding is loose. Instead, treat
-		// unset as "nothing to bind against" — the check is
-		// necessarily best-effort for those configs.
-		return nil
+		// The s3.* form: bind on its endpoint, bucket and prefix,
+		// written the way storage_url would name the same destination.
+		s3 := v.Config.S3
+		configured = "s3://" + s3.Bucket + "/" + s3.Prefix + "?endpoint=" + s3.Endpoint
 	}
 
 	stored, err := v.Repositories.LocalMeta.Get(v.ctx, database.LocalMetaKeyStorageURL)
@@ -96,7 +95,8 @@ func buildBindingMismatchMessage(stored, configured string) string {
 		"future snapshots referencing blobs that don't exist at the new destination.\n" +
 		"\n" +
 		"To proceed, either:\n" +
-		"  - revert storage_url in your config to the bound destination, or\n" +
+		"  - revert storage_url (or the s3.* endpoint, bucket and prefix) in your\n" +
+		"    config to the bound destination, or\n" +
 		"  - run 'vaultik database delete' to discard the local index and rebuild it\n" +
 		"    from a fresh full backup against the new destination"
 }

internal/vaultik/storage_bind_test.go

@@ -76,3 +76,51 @@ func TestEnsureStorageBinding_MismatchRefuses(t *testing.T) {
 	assert.Contains(t, err.Error(), "file:///mnt/backups/new")
 	assert.Contains(t, err.Error(), "vaultik database delete")
 }
+
+// A config with no storage_url names its destination with s3.endpoint,
+// s3.bucket and s3.prefix; a change to any of them must be refused just
+// as a changed storage_url is.
+func TestEnsureStorageBinding_S3FieldsChangeRefuses(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	bound := config.S3Config{
+		Endpoint: "https://s3.example.com",
+		Bucket:   "bucket-a",
+		Prefix:   "backups",
+	}
+
+	tests := []struct {
+		name    string
+		changed config.S3Config
+	}{
+		{"bucket", config.S3Config{
+			Endpoint: bound.Endpoint, Bucket: "bucket-b", Prefix: bound.Prefix,
+		}},
+		{"prefix", config.S3Config{
+			Endpoint: bound.Endpoint, Bucket: bound.Bucket, Prefix: "other",
+		}},
+		{"endpoint", config.S3Config{
+			Endpoint: "https://s3.other.com", Bucket: bound.Bucket, Prefix: bound.Prefix,
+		}},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			tv, _ := buildBindTestVaultik(t, "")
+
+			tv.Config.S3 = bound
+			require.NoError(t, tv.EnsureStorageBinding(), "first use binds")
+			require.NoError(t, tv.EnsureStorageBinding(), "same destination passes")
+
+			tv.Config.S3 = tt.changed
+			err := tv.EnsureStorageBinding()
+			require.Error(t, err)
+			assert.Contains(t, err.Error(),
+				"local index is bound to a different backup destination")
+			assert.Contains(t, err.Error(), "vaultik database delete")
+		})
+	}
+}