Weekly to monthly error checks on MySQL tables is recommended. Best is to use:
# isamchk -s -O readbuffer=2M */*.ISM
Other options allow automatic correction of errors, but are dangerous if tables are accessed while isamchk is running.
Other isamchk options allow recovery of space after frequent insert/delete of addresses (can also be done with ‘OPTIMIZE TABLE’), key optimization, etc. See the MySQL documentation for more info.