AdguardTeam/AdGuardHome · critical

loading db: %w

Error message

loading db: %w

What it means

The DHCP server failed during initial database loading (dbLoad) at Create time; the message wraps any of the read/decode/lease-conversion/reset errors (errors 109–112). It prevents the server from starting with an unusable lease DB.

Source

Thrown at internal/dhcpd/dhcpd.go:154

	s.conf.Conf4 = conf.Conf4
	s.conf.Conf6 = conf.Conf6

	if s.conf.Enabled && !v4Enabled && !v6Enabled {
		return nil, fmt.Errorf("neither dhcpv4 nor dhcpv6 srv is configured")
	}

	// Migrate leases db if needed.
	err = migrateDB(conf)
	if err != nil {
		// Don't wrap the error since it's informative enough as is.
		return nil, err
	}

	// Don't delay database loading until the DHCP server is started,
	// because we need static leases functionality available beforehand.
	err = s.dbLoad()
	if err != nil {
		return nil, fmt.Errorf("loading db: %w", err)
	}

	return s, nil
}

// setServers updates DHCPv4 and DHCPv6 servers created from the provided
// configuration conf.  It returns the status of both the DHCPv4 and the DHCPv6
// servers, which is always false for corresponding server on any error.
func (s *server) setServers(
	ctx context.Context,
	conf *ServerConfig,
) (v4Enabled, v6Enabled bool, err error) {
	v4conf := conf.Conf4
	v4conf.Logger = s.conf.Logger.With("ip_version", "4")
	v4conf.InterfaceName = s.conf.InterfaceName
	v4conf.notify = s.onNotify
	v4conf.Enabled = s.conf.Enabled && v4conf.RangeStart.IsValid()

View on GitHub (pinned to b41aefbe51)

Solutions

1. Read the wrapped error to identify the specific stage (read/decode/parse/reset)
2. Fix or delete the offending leases file (dynamic leases are re-acquired automatically)
3. Ensure the service user has read/write access to the data directory

// pre-check DB readability/validity
if data, err := os.ReadFile(dbPath); err == nil && !json.Valid(data) { /* move aside */ }

s, err := dhcpd.Create(ctx, conf)
if err != nil {
    if strings.Contains(err.Error(), "loading db") { /* recover/rotate leases file, retry once */ }
    return err
}

When it happens

Trigger: Calling Create when the leases file is unreadable, invalid JSON, contains bad MAC/RFC3339 values, or lease data incompatible with current config.

Common situations: First start after a crash corrupted leases.json; permission problems in the data dir; subnet/range changes invalidating stored leases.

Related errors

• parsing hardware address: %w
• parsing expiry time: %w
• decoding db: %w
• reading db: %w
• resetting dhcpv4 leases: %w

AI-assisted analysis of AdguardTeam/AdGuardHome@b41aefbe51 (2026-08-27). Data as JSON: /api/errors/92d50623f8623ed3. Report an issue: GitHub.