inno diff

Compare two InnoDB tablespace files page-by-page.

Synopsis

inno diff <file1> <file2> [-v] [-b] [-p <page>] [--json] [--page-size <size>] [--keyring <path>]

Description

Reads two InnoDB tablespace files and compares them page-by-page, reporting which pages are identical, modified, or only present in one file.

Three levels of comparison detail are available:

Quick comparison (default): Performs full-page byte equality checks and reports a summary of identical, modified, and file-only page counts.
Header field diff (-v): For modified pages, decodes and compares the FIL header fields (checksum, page number, prev/next pointers, LSN, page type, flush LSN, space ID) and reports which fields changed.
Byte-range scan (-v -b): In addition to header diffs, scans the full page content to identify the exact byte offset ranges where data differs, along with a total bytes-changed count and percentage.

When files have different page sizes, only the FIL headers (first 38 bytes) are compared and a warning is displayed.

Flags

Flag	Short	Required	Default	Description
`<file1>`	--	Yes	--	First InnoDB data file (.ibd). Positional argument.
`<file2>`	--	Yes	--	Second InnoDB data file (.ibd). Positional argument.
`--verbose`	`-v`	No	Off	Show per-page header field diffs for modified pages.
`--byte-ranges`	`-b`	No	Off	Show exact byte-range diffs for changed pages. Requires `-v`.
`--page <number>`	`-p`	No	All pages	Compare a single page only.
`--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

Quick comparison of two tablespace files

inno diff original.ibd modified.ibd

Verbose field-level diff

inno diff original.ibd modified.ibd -v

Verbose with byte-range analysis

inno diff original.ibd modified.ibd -v -b

Compare a single page

inno diff original.ibd modified.ibd -p 3 -v

JSON output

inno diff original.ibd modified.ibd --json | jq '.summary'

Output

Text Mode

Comparing:
  File 1: original.ibd (7 pages, 16384 bytes/page)
  File 2: modified.ibd (7 pages, 16384 bytes/page)

Summary:
  Identical pages:  5
  Modified pages:   2
  Only in file 1:   0
  Only in file 2:   0

Modified pages: 3, 4

With -v, modified pages show field-level changes:

Page 3: MODIFIED
  Checksum: 0xA3B1C5D7 -> 0x12345678
  LSN: 5539 -> 6012
  Page Type: INDEX (unchanged)

With -v -b, byte-range diffs are appended:

  Byte diff ranges:
    0-4 (4 bytes)
    38-16376 (16338 bytes)
  Total: 16342 bytes changed (99.7% of page)

JSON Mode

{
  "file1": { "path": "original.ibd", "page_count": 7, "page_size": 16384 },
  "file2": { "path": "modified.ibd", "page_count": 7, "page_size": 16384 },
  "page_size_mismatch": false,
  "summary": {
    "identical": 5,
    "modified": 2,
    "only_in_file1": 0,
    "only_in_file2": 0
  },
  "modified_pages": [
    {
      "page_number": 3,
      "file1_header": { "checksum": "0xA3B1C5D7", "lsn": 5539, "page_type": "INDEX" },
      "file2_header": { "checksum": "0x12345678", "lsn": 6012, "page_type": "INDEX" },
      "changed_fields": [
        { "field": "Checksum", "old_value": "0xA3B1C5D7", "new_value": "0x12345678" },
        { "field": "LSN", "old_value": "5539", "new_value": "6012" }
      ]
    }
  ]
}

IDB Utils Documentation