aria_chk is used to check, repair, optimize, sort and get information about Aria tables.

In MariaDB 5.1 it was known as maria_chk.

With the MariaDB server you can use CHECK TABLE, REPAIR TABLE and OPTIMIZE TABLE to do similar things.

Note: aria_chk should not be used when MariaDB is running. MariaDB assumes that no one is changing the tables it's using!


aria_chk [OPTIONS] aria_tables[.MAI]

Aria table information is stored in 2 files: the .MAI file contains base table information and the index and the .MAD file contains the data. aria_chk takes one or more .MAI files as arguments.

The following groups are read from the my.cnf files:

  • [maria_chk]
  • [aria_chk]

Options and Variables

Global options

The following options to handle option files may be given as the first argument:

Option Description
--print-defaults Print the program argument list and exit.
--no-defaults Don't read default options from any option file.
--defaults-file=# Only read default options from the given file #.
--defaults-extra-file=# Read this file after the global files are read.

Main arguments

Option Description
-#, --debug=... Output debug log. Often this is 'd:t:o,filename'.
-H, --HELP Display this help and exit.
-?, --help Display this help and exit.
--datadir=path Path for control file (and logs if --logdir not used).
--ignore-control-file Don't open the control file. Only use this if you are sure the tables are not used by another program
--logdir=path Path for log files.
--require-control-file Abort if we can't find/read the maria_log_control file
-s, --silent Only print errors. One can use two -s to make aria_chk very silent.
-t, --tmpdir=path Path for temporary files. Multiple paths can be specified, separated by colon (:) on Unix or semicolon (;) on Windows. They will be used in a round-robin fashion.
-v, --verbose Print more information. This can be used with --description and --check. Use many -v for more verbosity.
-V, --version Print version and exit.
-w, --wait Wait if table is locked.

Check options (--check is the default action for aria_chk):

Option Description
-c, --check Check table for errors.
-e, --extend-check Check the table VERY throughly. Only use this in extreme cases as aria_chk should normally be able to find out if the table is ok even without this switch.
-F, --fast Check only tables that haven't been closed properly.
-C, --check-only-changed Check only tables that have changed since last check.
-f, --force Restart with '-r' if there are any errors in the table. States will be updated as with '--update-state'.
-i, --information Print statistics information about table that is checked.
-m, --medium-check Faster than extend-check, and finds 99.99% of all errors. Should be good enough for most cases.
-U, --update-state Mark tables as crashed if any errors were found and clean if check didn't find any errors but table was marked as 'not clean' before. This allows one to get rid of warnings like 'table not properly closed'. If table was updated, update also the timestamp for when the check was made. This option is on by default! Use --skip-update-state to disable.
-T, --read-only Don't mark table as checked.

Recover (repair) options (When using '--recover' or '--safe-recover'):

Option Description
-B, --backup Make a backup of the .MAD file as 'filename-time.BAK'.
--correct-checksum Correct checksum information for table.
-D, --data-file-length=# Max length of data file (when recreating data file when it's full).
-e, --extend-check Try to recover every possible row from the data file Normally this will also find a lot of garbage rows; Don't use this option if you are not totally desperate.
-f, --force Overwrite old temporary files.
-k, --keys-used=# Tell MARIA to update only some specific keys. # is a bit mask of which keys to use. This can be used to get faster inserts.
--max-record-length=# Skip rows bigger than this if aria_chk can't allocate memory to hold it.
-r, --recover Can fix almost anything except unique keys that aren't unique.
-n, --sort-recover Forces recovering with sorting even if the temporary file would be very big.
-p, --parallel-recover Uses the same technique as '-r' and '-n', but creates all the keys in parallel, in different threads.
-o, --safe-recover Uses old recovery method; Slower than '-r' but can handle a couple of cases where '-r' reports that it can't fix the data file.
--transaction-log Log repair command to transaction log. This is needed if one wants to use the maria_read_log to repeat the repair.
--character-sets-dir=... Directory where character sets are.
--set-collation=name Change the collation used by the index.
-q, --quick Faster repair by not modifying the data file. One can give a second '-q' to force aria_chk to modify the original datafile in case of duplicate keys. NOTE: Tables where the data file is currupted can't be fixed with this option.
-u, --unpack Unpack file packed with aria_pack.

Other options

Option Description
-a, --analyze Analyze distribution of keys. Will make some joins in MariaDB faster. You can check the calculated distribution by using '--description --verbose table_name'.
--stats_method=name Specifies how index statistics collection code should treat NULLs. Possible values of name are "nulls_unequal" (default for 4.1/5.0), "nulls_equal" (emulate 4.0), and "nulls_ignored".
-d, --description Prints some information about table.
-A, --set-auto-increment[=value] Force auto_increment to start at this or higher value If no value is given, then sets the next auto_increment value to the highest used value for the auto key + 1.
-S, --sort-index Sort index blocks. This speeds up 'read-next' in applications.
-R, --sort-records=# Sort records according to an index. This makes your data much more localized and may speed up things (It may be VERY slow to do a sort the first time!).
-b, --block-search=# Find a record, a block at given offset belongs to.
-z, --zerofill Remove transaction id's from the data and index files and fills empty space in the data and index files with zeroes. Zerofilling makes it possible to move the table from one system to another without the server having to do an automatic zerofill. It also allows one to compress the tables better if one want to archive them.
--zerofill-keep-lsn Like --zerofill but does not zero out LSN of data/index pages.


Option Description
page_buffer_size Size of page buffer. Used by --safe-repair
read_buffer_size Read buffer size for sequential reads during scanning
write_buffer_size Write buffer size for sequential writes during repair of fixed size or dynamic size rows
sort_buffer_size Size of sort buffer. Used by --recover
sort_key_blocks Internal buffer for sorting keys; Don't touch :)


One main usage of aria_chk is when you want to do a fast check of all Aria tables in your system. This is faster than doing it in MariaDB as you can allocate all free memory to the buffers.

Assuming you have a bit more than 2G free memory.

The following commands, run in the MariaDB data directory, check all your tables and repairs only those that have an error:

aria_chk --check --sort_order --force --sort_buffer_size=1G */*.MAI

If you want to optimize all your tables: (The --zerofill is used here to fill up empty space with \0 which can speed up compressed backups).

aria_chk --analyze --sort-index --page_buffer_size=1G --zerofill */*.MAI

In case you have a serious problem and have to use --safe-recover:

aria_chk --safe-recover --zerofill --page_buffer_size=2G */*.MAI
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