Thursday, May 17, 2012

ESXi 5 Lun trespassing (lun thrashing) on EMC VNX

Problem description/symptoms/errors:
Issue with a new EMC VNX Lun.
The lun seems to be moving between service process A & B and EMC support claims that it is being initiated by the VMware.
10Gig storage back end network is configured but it fails from the host but when the MTU is changed it works fine. The default was MTU was 1500 and now it is 1344 on the host side on the vswitch and after doing this change, now the ping drop or the moving of the lun from the process A to B and vice versa is less but still occurring.

Action Taken:
changed the MTU back to 1500 and there was no ping drop or the movement of the lun between process A&B or vice versa.
Disabled the resignaturing esxcfg-advcfg -s 0 /LVM/EnableResignature  on all hosts and the trespassing stopped.