kopia/kopia · error

unable to delete blob

Error message

unable to delete blob %v

What it means

deleteBlobsFromStorageAndCache failed to delete a specific blob from the underlying blob storage (m.st.DeleteBlob). Errors equal to blob.ErrBlobNotFound are deliberately tolerated (already deleted); any other error is wrapped with the blob ID. This aborts the delete loop, leaving remaining blobs undeleted.

Solutions

1. Read the blob ID from the message and the wrapped provider error for the root cause.
2. Verify the storage credentials/role permit DeleteBlob operations.
3. Check for immutability/retention policies (S3 Object Lock, Azure immutability) on the bucket/container.
4. Retry the operation; missing blobs are already tolerated so a rerun only targets the remaining blobs.

Example fix

// before
if err := m.st.DeleteBlob(ctx, blobID); err != nil && !errors.Is(err, blob.ErrBlobNotFound) {
	return errors.Wrapf(err, "unable to delete blob %v", blobID)
}
// after
if err := m.st.DeleteBlob(ctx, blobID); err != nil && !errors.Is(err, blob.ErrBlobNotFound) {
	if retry.IsTransient(err) {
		continue // or back off and retry the whole pass
	}
	return errors.Wrapf(err, "unable to delete blob %v", blobID)
}

// Go: verify delete permission before GC passes
if err := probeBlobDelete(ctx, m.st, testBlobID); err != nil {
	return fmt.Errorf("storage delete probe failed: %w", err)
}

if err != nil && strings.Contains(err.Error(), "unable to delete blob ") { // back off and retry; ErrBlobNotFound tolerated on rerun
	backoff.Retry(func() error { return mgr.Compact(ctx) }, backoff.WithMaxRetries(3, time.Second))
}

When it happens

Trigger: m.st.DeleteBlob(ctx, blobID) returns a non-ErrBlobNotFound error during deleteOldBlobs or cleanup — e.g. storage API failure, permission denial, network error, or a conditional-delete conflict.

Common situations: Cloud credentials lacking delete permission (write-only or read-only policy), blob locked by an immutability/retention policy (S3 Object Lock, WORM), transient provider 5xx, or eventual-consistency races where a replica reports the blob in a conflicting state.

Related errors

• delete directory
• delete file
• DeleteBlob( )
• deleting
• error deleting blob

AI-assisted analysis of kopia/kopia@82495e54b5 (2026-09-07). Data as JSON: /api/errors/6fa64b907a2bf2d6. Report an issue: GitHub.

Appendix: source

Thrown at repo/content/indexblob/index_blob_manager_v0.go:412

		BlobIDs:             blobIDs,
		CleanupScheduleTime: cleanupScheduleTime,
	})
	if err != nil {
		return errors.Wrap(err, "unable to marshal cleanup log bytes")
	}

	if _, err := m.enc.EncryptAndWriteBlob(ctx, gather.FromSlice(payload), V0CleanupBlobPrefix, ""); err != nil {
		return errors.Wrap(err, "unable to cleanup log")
	}

	return nil
}

func (m *ManagerV0) deleteBlobsFromStorageAndCache(ctx context.Context, blobIDs []blob.ID) error {
	for _, blobID := range blobIDs {
		if err := m.st.DeleteBlob(ctx, blobID); err != nil && !errors.Is(err, blob.ErrBlobNotFound) {
			contentlog.Log2(ctx, m.log, "delete-blob failed", blobparam.BlobID("blobID", blobID), logparam.Error("err", err))
			return errors.Wrapf(err, "unable to delete blob %v", blobID)
		}

		contentlog.Log1(ctx, m.log, "delete-blob succeeded", blobparam.BlobID("blobID", blobID))
	}

	return nil
}

func (m *ManagerV0) cleanup(ctx context.Context, maxEventualConsistencySettleTime time.Duration) error {
	allCleanupBlobs, err := blob.ListAllBlobs(ctx, m.st, V0CleanupBlobPrefix)
	if err != nil {
		return errors.Wrap(err, "error listing cleanup blobs")
	}

	// determine latest storage write time of a cleanup blob
	var latestStorageWriteTimestamp time.Time

	for _, cb := range allCleanupBlobs {

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