Read-only LUN partition

Hi,

I have an server running Red Hat Enterprise Linux Server release 6.4 which is getting a LUN from IBM DS8700 through multipath and its running fine most of the time. Just randomly the LUN partition gets into read-only mode.

The /var/log/messages does not show up anything.

I am not very clear where to troubleshoot, whether the FC port, Cable or anything else. Kindly advise on how to approach this.

Regards,
Ritesh Vishwakarma