I use myisamchk *.MYI to optimise all my tables.
However this no longer works with the MYI extension
# myisamchk mytable
Checking MyISAM file: mytable
Data records: 17952 Deleted blocks: 0
- check file-size
- check record delete-chain
- check key delete-chain
- check index reference
- check data record references index: 1
# myisamchk mytable.MYI
myisamchk: error: 140 when opening MyISAM-table 'mytable.MYI'
SHOW CREATE TABLE mytable
.