ipfs/kubo · error

failed to read key: %w

Error message

failed to read key: %w

What it means

`ipfs diag datastore get <key>` wraps any datastore read error that is NOT ErrNotFound as 'failed to read key'. It signals real I/O or backend problems (corruption, permissions, backend failure) rather than a missing key.

Source

Thrown at core/commands/diag.go:197

	},
	NoRemote: true,
	PreRun:   DaemonNotRunning,
	Run: func(req *cmds.Request, res cmds.ResponseEmitter, env cmds.Environment) error {
		ds, closer, err := openDiagDatastore(env)
		if err != nil {
			return err
		}
		defer closer()

		keyStr := req.Arguments[0]
		key := datastore.NewKey(keyStr)

		val, err := ds.Get(req.Context, key)
		if err != nil {
			if errors.Is(err, datastore.ErrNotFound) {
				return fmt.Errorf("key not found: %s", keyStr)
			}
			return fmt.Errorf("failed to read key: %w", err)
		}

		result := &diagDatastoreGetResult{
			Key:   keyStr,
			Value: val,
		}

		if hexDump, _ := req.Options[diagDatastoreHexOptionName].(bool); hexDump {
			result.HexDump = hex.Dump(val)
		}

		return cmds.EmitOnce(res, result)
	},
	Type: diagDatastoreGetResult{},
	Encoders: cmds.EncoderMap{
		cmds.Text: cmds.MakeTypedEncoder(func(req *cmds.Request, w io.Writer, result *diagDatastoreGetResult) error {
			if result.HexDump != "" {
				fmt.Fprintf(w, "Key: %s\nHex Dump:\n%s", result.Key, result.HexDump)

View on GitHub (pinned to 329838acdf)

Solutions

1. Check the wrapped underlying error in verbose output and daemon/diag logs
2. Verify disk space, permissions, and filesystem health on the repo directory
3. Repair or restore the datastore (backend-specific repair tools, or re-init and re-import from backups)

err := diagDatastoreGet(key)
if err != nil && strings.Contains(err.Error(), "failed to read key") { inspectUnderlying(err); checkDiskHealth() }

When it happens

Trigger: ds.Get(req.Context, key) returns an error other than datastore.ErrNotFound: disk I/O failure, permission denied, corrupt backend (badger/levelds/pebble) errors.

Common situations: Disk full or failing; wrong permissions on the repo directory; corrupted datastore backend after a crash; container filesystem issues.

Related errors

• failed to open repo: %w
• key not found: %s
• reading new root block: %w
• encoding PEM block: %w
• flushing %s: %w

AI-assisted analysis of ipfs/kubo@329838acdf (2026-09-03). Data as JSON: /api/errors/35e918c10158d83f. Report an issue: GitHub.