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 mysqldump to make a backup of the tables within the tablespace.
Invoke innochecksum like this:
shell> innochecksum [options
] file_name
innochecksum supports the following options. For options that refer to page numbers, the numbers are zero-based.