influxdata/influxdb · critical · Error

crc32 checksum mismatch

Error message

crc32 checksum mismatch

What it means

serialize::Error::Crc32Mismatch is raised when the CRC32 checksum stored in a WAL file does not match the checksum computed over the bytes actually read. Each WAL file ends with a crc32 of its contents; a mismatch means the file's payload was corrupted in transit or at rest, so the library refuses to deserialize it rather than replaying garbage.

Solutions

1. Treat the file as corrupt: restore it from backup, or skip it if losing that segment's buffered (not yet snapshot) data is acceptable.
2. Check storage health (disk SMART, filesystem errors, dmesg) for underlying corruption causes.
3. Re-copy the file with checksum verification (e.g. rsync -c) if it was transferred between hosts.
4. Avoid any post-write modification of WAL files; never edit them by hand.

Example fix

# before: suspect corrupted file
# verify_file_type_and_deserialize(...) -> Crc32Mismatch
# after: restore from backup
aws s3 cp s3://backup/wal/1/1712345678/0000000008.wal wal/1/1712345678/0000000008.wal

// independently verify crc32 before handing bytes to the library
let expected = u32::from_be_bytes(bytes[bytes.len()-4..].try_into()?);
let computed = crc32fast::hash(&bytes[..bytes.len()-4]);
if expected != computed { /* corrupt: restore/skip */ }

match verify_file_type_and_deserialize(&bytes) {
    Err(serialize::Error::Crc32Mismatch) => restore_from_backup_or_skip(path),
    other => other?,
}

When it happens

Trigger: verify_file_type_and_deserialize reads the file body and trailing crc32 (serialize.rs:73) and the computed checksum differs from the stored one — bit rot, partial writes, or a file modified after being written.

Common situations: Hardware/storage corruption; interrupted writes that committed data bytes but not (correct) trailer bytes; manually editing a .wal file; copying files with a lossy transfer; object-store layers that don't preserve byte fidelity.

Understand the failure class

Background: Checksum mismatch errors: "checksum verification failed", "digest mismatch", "expected vs actual checksum" — what they mean and how to fix them — this error's family across 41 libraries.

Related errors

• Invalid wal file identifier
• WAL file too small: expected at least
• bitcode error
• deserialize error
• try from slice error

AI-assisted analysis of influxdata/influxdb@06200ef96b (2026-09-19). Data as JSON: /api/errors/97a0a6b5dd29758a. Report an issue: GitHub.

Appendix: source

Thrown at influxdb3_wal/src/serialize.rs:20

//! buffered in memory before writing it in a single PUT operation to object store, this works
//! a little differently than a traditional WAL that appends.

use crate::WalContents;
use byteorder::{BigEndian, ReadBytesExt};
use bytes::Bytes;
use std::io::Cursor;
use std::mem::size_of;
use thiserror::Error;

#[derive(Debug, Error)]
pub enum Error {
    #[error("Invalid wal file identifier")]
    InvalidWalFile,

    #[error("WAL file too small: expected at least {expected} bytes, but got {actual} bytes")]
    WalFileTooSmall { expected: usize, actual: usize },

    #[error("crc32 checksum mismatch")]
    Crc32Mismatch,

    #[error("bitcode error: {0}")]
    Bitcode(#[from] bitcode::Error),

    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),

    #[error("try from slice error {0}")]
    TryFromSlice(#[from] std::array::TryFromSliceError),
}

pub(crate) type Result<T, E = Error> = std::result::Result<T, E>;

/// The first bytes written into a wal file to identify it and its version.
const FILE_TYPE_IDENTIFIER: &[u8] = b"idb3.001";

#[inline(always)]

View on GitHub (pinned to 06200ef96b)