I would like to know the correct way to move the mysql data directory to
a different disk partition, so that the data can be accessed by mysql
under linux or windows. I'm using Ubuntu 7.1 and Windows XP.

I copied the data directory to a separate partition.
I then changed the datadir in my.cnf, but Mysql would not start, warning:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket
'/var/run/mysqld/mysqld.sock'

I'd appreciate your suggestions.
-B.