kopia/kopia · error

invalid parameters

Error message

invalid parameters

What it means

Initialize validates the proposed RepositoryConfig (block-format parameters such as encryption, hashing, splitter) via repoConfig.Validate(). If any parameter is out of range or mutually inconsistent, Initialize aborts with 'invalid parameters', wrapping the underlying validation error. This happens before any blob is written, so the storage is left untouched.

Solutions

1. Read the wrapped inner error from Validate() — it names the exact offending field
2. Use format.DefaultContentFormat as a base and change only known-supported fields
3. Verify algorithm names/versions against the constants exported by the format package
4. Omit optional fields so library defaults are applied instead of zero values

Example fix

// before
repoConfig := format.RepositoryConfig{ContentFormat: format.ContentFormat{EncryptionAlgorithm: "AES-GCM"}}
// after
repoConfig := format.DefaultContentFormat // use supported defaults, then override individual supported fields

// Validate the RepositoryConfig before passing it to Initialize
if err := repoConfig.Validate(); err != nil {
    return fmt.Errorf("refusing to initialize with invalid config: %w", err)
}

if _, err := format.Initialize(ctx, st, opts, password); err != nil {
    if strings.Contains(err.Error(), "invalid parameters") {
        // rebuild with DefaultContentFormat and retry
        opts.BlockFormat = format.DefaultContentFormat
        return format.Initialize(ctx, st, opts, password)
    }
    return err
}

When it happens

Trigger: Calling format.Initialize with a RepositoryConfig containing an unsupported encryption algorithm, unknown hash function, invalid format version, or contradictory options (e.g. format version below minimum or above current write version).

Common situations: Programmatic repository creation passing custom ContentFormat fields; typos in algorithm names like 'CHACHA20-POLY1305' or 'BLAKE2B-256-128'; copying parameters from documentation of a different Kopia version.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• blob config
• both retention mode and period must be provided when…
• bucket name must be specified
• epoch advance on count too low
• epoch advance on size too low

AI-assisted analysis of kopia/kopia@82495e54b5 (2026-09-07). Data as JSON: /api/errors/4022ea1b944d2b97. Report an issue: GitHub.

Appendix: source

Thrown at repo/format/format_manager.go:469

	}

	// In legacy versions, the KeyDerivationAlgorithm may not be present in the
	// KopiaRepositoryJson. In those cases default to using Scrypt.
	if formatBlob.KeyDerivationAlgorithm == "" {
		formatBlob.KeyDerivationAlgorithm = DefaultKeyDerivationAlgorithm
	}

	if len(formatBlob.UniqueID) == 0 {
		formatBlob.UniqueID = randomBytes(UniqueIDLengthBytes)
	}

	formatEncryptionKey, err := formatBlob.DeriveFormatEncryptionKeyFromPassword(password)
	if err != nil {
		return errors.Wrap(err, "unable to derive format encryption key")
	}

	if err = repoConfig.Validate(); err != nil {
		return errors.Wrap(err, "invalid parameters")
	}

	if err = blobcfg.Validate(); err != nil {
		return errors.Wrap(err, "blob config")
	}

	if err = formatBlob.EncryptRepositoryConfig(repoConfig, formatEncryptionKey); err != nil {
		return errors.Wrap(err, "unable to encrypt format bytes")
	}

	if err := formatBlob.WriteBlobCfgBlob(ctx, st, blobcfg, formatEncryptionKey); err != nil {
		return errors.Wrap(err, "unable to write blobcfg blob")
	}

	if err := formatBlob.WriteKopiaRepositoryBlob(ctx, st, blobcfg); err != nil {
		return errors.Wrap(err, "unable to write format blob")
	}

View on GitHub (pinned to 82495e54b5)