So you want to use a GFS shared storage option and have mysql run its databases on that shared storage? Well I had this problem at work and it took a bit to figure out since there wasn't much documentation on it but it works. It is slower then just using it over ext3. I have never tested it on a mysql cluster so I am unsure of the speeds compared to that
So the first thing you want to do is edit your /etc/my.cnf file
in the [mysqld] section you want to add this
skip-innodb
Then in the /etc/init.d/mysql script you want to add --external-locking to the following line so it looks like
/usr/bin/mysqld_safe --defaults-file=/etc/my.cnf --external-locking --pid-file="$mypidfile" --log-error="$errlogfile" >/dev/null 2>&1 &
That is pretty much it.. Now if you want to connect to localhost you need to set a new sock file
so in [mysqld] I do something like this
socket=/var/lib/sock/mysql.sock
and in the [client] section ( create one if one isn't in the cnf file)
socket=/var/lib/sock/mysql.sock
Then
mkdir /var/lib/sock/ chown mysql:mysql /var/lib/sock/
mysql should now run over gfs!