Move Database to a mounted drive in linux (no replies)

Hi,
My requirement is to create a large DB, so I am trying to move the DB from default location to mounted drive(LUN) which has enough space.
After copying the db files to new location and making changes in "my.cnf" file. i.e. I am getting error when i start the mysql service,
But the surprise is that, If I try to move it to some local drive(not mounted LUN) its working.

Detils of setup:

OS : Redhat 5
Mysql : 5.5.14

Error :
/etc/init.d/mysql restart
MySQL server PID file could not be found! [FAILED]
Starting MySQL...The server quit without updating PID file [FAILED]p/mysql-data/rhel5p.pid).


Thanks in advance....

Regards
Pavan KUlkarni