I seem to have hit another roadblock...
As the zimbra user:
So I did some digging and tried starting the mysql.server directly:
202:/opt/zimbra/mysql/bin zimbra$ mysql.server start
202:/opt/zimbra/mysql/bin zimbra$ chown: /opt/zimbra/log/mysqld.log: Operation not permitted
Starting mysqld daemon with databases from /opt/zimbra/db/data
STOPPING server from pid file /opt/zimbra/db/mysql.pid
051123 13:47:31 mysqld ended
I changed permissions (chown and chmod) on the files suggested and still no joy.