If you’re trying to repair large MyISAM tables in MySQL, you can run into the following restriction, because of the limited size of the default Sort Buffer.
srv # myisamchk -r table.MYI - recovering (with sort) MyISAM-table 'table.MYI' Data records: 335045 - Fixing index 1 Found block that points outside data file at 1509428340 Found link that points at 61778810452273 (outside data file) at 1509428348 - Fixing index 2 - Fixing index 3 - Fixing index 4 - Fixing index 5 - Fixing index 6 - Fixing index 7 - Fixing index 8 myisamchk: error: myisam_sort_buffer_size is too small MyISAM-table 'table.MYI' is not fixed because of errors
While the fix seems obvious (increase the myisam_sort_buffer_size), it’s a bit confusing.
The MySQL server knows 2 variables, myisam_sort_buffer_size and sort_buffer_size. The first one is the one used for the buffer in “Repair by sort”. The second one is used to buffer a filesort.
The myisamchk command does not have myisam_sort_buffer_size. myisamchk has only sort_buffer_size, which is used for “Repair by sort”.
The following increases the buffer size that is needed.
srv # myisamchk -r -q table.MYI --sort_buffer_size=2G
Or increase the memory, if it’s still not sufficient to do the repair.