inno checksum

Validate page checksums for every page in an InnoDB tablespace.

Synopsis

inno checksum -f <file> [-v] [--json] [--page-size <size>] [--keyring <path>]

Description

Iterates over all pages in a tablespace and validates the stored checksum (bytes 0-3 of the FIL header) against multiple algorithms:

CRC-32C (MySQL 5.7.7+): XORs two independent CRC-32C values computed over bytes [4..26) and [38..page_size-8). This is the default algorithm for modern MySQL.
Legacy InnoDB (MySQL < 5.7.7): Uses ut_fold_ulint_pair with u32 wrapping arithmetic over the same two byte ranges.
MariaDB full_crc32 (MariaDB 10.5+): Single CRC-32C over bytes [0..page_size-4). Checksum is stored in the last 4 bytes of the page, not the FIL header. Detected via FSP flags bit 4.

A page is considered valid if any algorithm matches the stored checksum value.

Additionally checks LSN consistency: the low 32 bits of the header LSN (bytes 16-23) must match the LSN value in the 8-byte FIL trailer at the end of the page.

Special pages are handled as follows:

Pages with checksum 0xDEADBEEF (magic value) are skipped.
All-zero pages are counted as empty and skipped.

The process exits with code 1 if any page has an invalid checksum, making this suitable for scripted integrity checks.

Flags

Flag	Short	Required	Default	Description
`--file <path>`	`-f`	Yes	--	Path to the InnoDB data file (.ibd).
`--verbose`	`-v`	No	Off	Show per-page checksum details (algorithm, stored/calculated values).
`--json`	--	No	Off	Output in JSON format.
`--page-size <size>`	--	No	Auto-detect	Override page size.
`--keyring <path>`	--	No	--	Path to MySQL keyring file for decrypting encrypted tablespaces.

Examples

Validate all page checksums

inno checksum -f /var/lib/mysql/sakila/actor.ibd

Verbose per-page output

inno checksum -f actor.ibd -v

JSON output for scripting

inno checksum -f actor.ibd --json

Use in a script with exit code

if inno checksum -f actor.ibd; then
    echo "All checksums valid"
else
    echo "Corrupt pages detected!"
fi

Output

Text Mode

Displays a progress bar during validation, then prints a summary:

Validating checksums for actor.ibd (7 pages, page size 16384)...

Summary:
  Total pages: 7
  Empty pages: 3
  Valid checksums: 4
  Invalid checksums: 0

With --verbose, each non-empty page is printed individually:

Page 0: OK (Crc32c, stored=2741936599, calculated=2741936599)
Page 1: OK (Crc32c, stored=1849326041, calculated=1849326041)
Page 3: INVALID checksum (stored=12345, calculated=2741936599, algorithm=Crc32c)

JSON Mode

{
  "file": "actor.ibd",
  "page_size": 16384,
  "total_pages": 7,
  "empty_pages": 3,
  "valid_pages": 4,
  "invalid_pages": 0,
  "lsn_mismatches": 0,
  "pages": []
}

With --verbose, the pages array includes every non-empty page. Without --verbose, only invalid pages and pages with LSN mismatches are included:

{
  "pages": [
    {
      "page_number": 3,
      "status": "invalid",
      "algorithm": "crc32c",
      "stored_checksum": 12345,
      "calculated_checksum": 2741936599,
      "lsn_valid": true
    }
  ]
}

The algorithm field will be one of: crc32c, innodb, mariadb_full_crc32, or none.

IDB Utils Documentation