If you see error messages in /var/log/mysql.log about a table being crashed, log into the mysql console and run:  recover table;

Pretty easy!

For tpcw, you can use this script to recover everything:

repair table item;
repair table country;
repair table author;
repair table customer;
repair table orders;
repair table order_line;
repair table cc_xacts;
repair table address;
repair table shopping_cart;
repair table shopping_cart_line;