innochecksum prints checksums for InnoDB files. This tool reads an InnoDB tablespace file, calculates the
checksum for each page, compares the calculated checksum to the stored checksum, and reports mismatches,
which indicate damaged pages. It was originally developed to speed up verifying the integrity of
tablespace files after power outages but can also be used after file copies. Because checksum mismatches
will cause InnoDB to deliberately shut down a running server, it can be preferable to use this tool
rather than waiting for a server in production usage to encounter the damaged pages.
innochecksum cannot be used on tablespace files that the server already has open. For such files, you
should use CHECK TABLE to check tables within the tablespace.
If checksum mismatches are found, you would normally restore the tablespace from backup or start the
server and attempt to use mariadb-dump to make a backup of the tables within the tablespace.
Invoke innochecksum like this:
shell> innochecksum[options]file_nameinnochecksum supports the following options. For options that refer to page numbers, the numbers are
zero-based.
• -?,--help
Displays help and exits.
• -anum,--allow-mismatches=#
Maximum checksum mismatch allowed before innochecksum terminates. Defaults to 0, which terminates on
the first mismatch.
• -c,--count
Print a count of the number of pages in the file.
• -enum,--end-page=#
End at this page number.
• -i,--per-page-details
Print out per-page detail information.
• -I,--info
Synonym for --help.
• -f,--leaf
Examine leaf index pages.
• -lfn,--log=fn
Log output to the specified filename, fn.
• -mnum,--merge=#
Leaf page count if merge given number of consecutive pages.
• -n,--no-check
Ignore the checksum verification. Until MariaDB 10.6, must be used with the --write option.
• -pnum,--page-num=#
Check only this page number.
• -Dname,--page-type-dump=name
Dump the page type info for each page in a tablespace.
• -S,--page-type-summary
Display a count of each page type in a tablespace.
• -snum,--start-page
Start at this page number.
• -u,--skip-corrupt
Skip corrupt pages.
• -Cname,--strict-check=name
Specify the strict checksum algorithm. One of: crc32, innodb, none. If not specified, validates
against innodb, crc32 and none. Removed in MariaDB 10.6.
• -wname,--write=name
Rewrite the checksum algorithm. One of crc32, innodb, none. An exclusive lock is obtained during use.
Use in conjunction with the -no-check option to rewrite an invalid checksum. Removed in MariaDB 10.6.
• -v,--verbose
Verbose mode; print a progress indicator every five seconds.
• -V,--version
Displays version information and exits.