inno recover

Assess page-level recoverability and count salvageable records in an InnoDB tablespace.

Synopsis

inno recover -f <file> [-p <page>] [-v] [--json] [--force] [--page-size <size>] [--keyring <path>]

Description

Scans a tablespace file and classifies each page into one of four states:

Intact: Checksum is valid and LSN is consistent between header and trailer.
Corrupt: Checksum mismatch or LSN inconsistency, but the FIL header is parseable.
Empty: All-zero page (allocated but unused).
Unreadable: Page data is too short or the FIL header cannot be parsed.

For INDEX pages, the compact record chain is walked to count recoverable user records. This gives a concrete estimate of how many rows can be salvaged from a damaged tablespace.

When page 0 is damaged and auto-detection fails, inno recover tries common page sizes (16K, 8K, 4K, 32K, 64K) in order, selecting the first one that divides evenly into the file size. Use --page-size to force a specific size when the heuristic is not sufficient.

Force mode

By default, records are only counted on intact INDEX pages. With --force, records are also extracted from corrupt pages that have valid-looking FIL headers. This is useful when the checksum is damaged but the record chain is still intact, allowing more data to be recovered.

Flags

Flag	Short	Required	Default	Description
`--file <path>`	`-f`	Yes	--	Path to the InnoDB data file (.ibd).
`--page <number>`	`-p`	No	All pages	Analyze a single page instead of a full scan.
`--verbose`	`-v`	No	Off	Show per-page details (type, status, LSN, record count).
`--json`	--	No	Off	Output in JSON format.
`--force`	--	No	Off	Extract records from corrupt pages with valid headers.
`--page-size <size>`	--	No	Auto-detect (with fallback)	Override page size. Critical when page 0 is corrupt.
`--keyring <path>`	--	No	--	Path to MySQL keyring file for decrypting encrypted tablespaces.

Examples

Quick recovery assessment

inno recover -f damaged_table.ibd

Verbose per-page analysis

inno recover -f damaged_table.ibd -v

Force-extract records from corrupt pages

inno recover -f damaged_table.ibd --force -v

Analyze a single page

inno recover -f damaged_table.ibd -p 3 -v

JSON output with per-page detail

inno recover -f damaged_table.ibd --json -v

Override page size for a file with corrupt page 0

inno recover -f damaged_table.ibd --page-size 16384

Output

Text Mode

Recovery Analysis: damaged_table.ibd
File size: 114688 bytes (7 pages x 16384 bytes)
Page size: 16384 (auto-detected)

Page Status Summary:
  Intact:         5 pages
  Corrupt:        1 pages (pages 3)
  Empty:          1 pages
  Unreadable:     0 pages
  Total:          7 pages

Recoverable INDEX Pages: 3 of 4
  Total user records: 200
  Records on corrupt pages: 52 (use --force to include)

Overall: 83.3% of pages intact

With --verbose, per-page lines are displayed before the summary:

Page    0: FSP_HDR        intact       LSN=1000
Page    1: IBUF_BITMAP    intact       LSN=1001
Page    2: INODE          intact       LSN=1002
Page    3: INDEX          CORRUPT      LSN=5000  records=52  checksum mismatch
Page    4: INDEX          intact       LSN=5001  records=100
Page    5: INDEX          intact       LSN=5002  records=100
Page    6: Allocated      empty        LSN=0

JSON Mode

{
  "file": "damaged_table.ibd",
  "file_size": 114688,
  "page_size": 16384,
  "total_pages": 7,
  "summary": {
    "intact": 5,
    "corrupt": 1,
    "empty": 1,
    "unreadable": 0
  },
  "recoverable_records": 200,
  "force_recoverable_records": 52,
  "pages": []
}

With --verbose, the pages array includes per-page detail. When combined with --verbose --json, each INDEX page also includes per-record data with byte offsets, heap numbers, delete marks, and hex-encoded record bytes.

IDB Utils Documentation