Backup Verification

The inno verify subcommand performs structural integrity checks on InnoDB tablespace files without requiring valid checksums. It can also verify backup chain continuity and redo log consistency.

Quick Start

Verify a single tablespace:

inno verify -f /var/lib/mysql/mydb/users.ibd

Verify a backup chain:

inno verify --chain full_backup.ibd incremental_1.ibd incremental_2.ibd

Verify redo log continuity:

inno verify -f users.ibd --redo /var/lib/mysql/ib_logfile0

Structural Checks

The verify subcommand runs six structural checks on every page in the tablespace:

Check	Description
PageNumberSequence	The page number stored at offset 4 matches its expected position in the file
SpaceIdConsistency	All pages have the same space ID as page 0
LsnMonotonicity	LSNs are non-decreasing across pages (within tolerance)
BTreeLevelConsistency	INDEX leaf pages have level 0, internal pages have level > 0
PageChainBounds	prev/next pointers are within file bounds; first page has prev = FIL_NULL
TrailerLsnMatch	The trailer LSN low-32 bits match the header LSN low-32 bits

Usage

Basic Verification

inno verify -f table.ibd

With verbose output showing per-page findings:

inno verify -f table.ibd -v

JSON Output

inno verify -f table.ibd --json

Example output:

{
  "file": "table.ibd",
  "total_pages": 128,
  "page_size": 16384,
  "passed": true,
  "findings": [],
  "summary": [
    {"kind": "PageNumberSequence", "pages_checked": 128, "issues_found": 0, "passed": true},
    {"kind": "SpaceIdConsistency", "pages_checked": 128, "issues_found": 0, "passed": true}
  ]
}

Backup Chain Verification

The --chain flag accepts multiple tablespace files and verifies that they form a valid backup chain based on LSN ordering.

inno verify --chain full.ibd incr1.ibd incr2.ibd

The chain verifier checks:

Files are ordered by ascending max LSN
No LSN gaps between consecutive files in the chain (the max LSN of file N should be less than or equal to the max LSN of file N+1)
All files have the same space ID
At least two files are provided

JSON Output

inno verify --chain full.ibd incr1.ibd --json

Returns a ChainReport with per-file info and any detected gaps.

Redo Log Continuity

The --redo flag verifies that a tablespace's LSN state is consistent with a redo log file.

inno verify -f table.ibd --redo /var/lib/mysql/ib_logfile0

This compares the checkpoint LSN from the redo log with the maximum LSN found in the tablespace. If the tablespace contains changes beyond the redo log's checkpoint, the redo log may be behind.

When to Use

After backups: Verify that backup files are structurally sound before relying on them for disaster recovery.
Before restores: Check that a backup chain is complete and contiguous.
Corruption diagnosis: Identify structural issues that go beyond checksum validation (which inno checksum handles).
Monitoring: Include in periodic health checks alongside inno audit and inno health.

IDB Utils Documentation