thanos-io/thanos · error

copying

Error message

copying

What it means

Wraps io.Copy feeding the file into the sha256 hasher in CalculateHash: reading the file's bytes failed mid-stream (I/O error, file truncated concurrently). The partial digest is discarded and hashing fails.

Solutions

1. Check disk health for read errors
2. Verify the file is not truncated or concurrently written
3. Retry hashing the file

When it happens

Trigger: Thrown at pkg/block/metadata/hash.go:54 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of thanos-io/thanos@35b8b99117 (2026-09-07). Data as JSON: /api/errors/3ad1195670b97f72. Report an issue: GitHub.

Appendix: source

Thrown at pkg/block/metadata/hash.go:54

// Equal returns true if two hashes are equal.
func (oh *ObjectHash) Equal(other *ObjectHash) bool {
	return oh.Value == other.Value
}

// CalculateHash calculates the hash of the given type.
func CalculateHash(p string, hf HashFunc, logger log.Logger) (ObjectHash, error) {
	switch hf {
	case SHA256Func:
		f, err := os.Open(filepath.Clean(p))
		if err != nil {
			return ObjectHash{}, errors.Wrap(err, "opening file")
		}
		defer runutil.CloseWithLogOnErr(logger, f, "closing %s", p)

		h := sha256.New()

		if _, err := io.Copy(h, f); err != nil {
			return ObjectHash{}, errors.Wrap(err, "copying")
		}

		return ObjectHash{
			Func:  SHA256Func,
			Value: hex.EncodeToString(h.Sum(nil)),
		}, nil
	}
	return ObjectHash{}, fmt.Errorf("hash function %v is not supported", hf)

}

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