FreeNAS 8.3 ISCSI & XenServer

Experienced something very strange in our XenServer farm. Noticed some VM’s were shutdown while others appeared UP, however, not responsive. I restarted the FreeNas server after trying to restart the ISCSI service failed. The server experienced a complete power outage in our datacenter even though it was plugged into A & B power. I’ll get into that later.

So, I rebooted the server but it didn’t come up – oh joy! Sent a ticket to the datacenter to check it and power-cycled it. It came online, however, our XenServers refused to fire up any VMs. I noticed this error while tailing the messages on one of the XenHosts.

Feb 23 22:45:06 san10 istgt[4393]: istgt_iscsi.c:2106:istgt_iscsi_op_login: ***ERROR*** access denied
Feb 23 22:45:09 san10 istgt[4393]: istgt_lu.c: 270:istgt_lu_access: ***WARNING*** access denied from iqn.2013-08.com.example:40cc6aa5 (10.1.201.10) to iqn.2011-03.example.org.istgt:money (10.1.201.20:3260,2)
Feb 23 22:45:09 san10 istgt[4393]: istgt_iscsi.c:2106:istgt_iscsi_op_login: ***ERROR*** access denied
Feb 23 22:45:13 san10 istgt[4393]: istgt_lu.c: 270:istgt_lu_access: ***WARNING*** access denied from iqn.2013-08.com.example:40cc6aa5 (10.1.201.10) to iqn.2011-03.example.org.istgt:money (10.1.201.20:3260,2)
Feb 23 22:45:13 san10 istgt[4393]: istgt_iscsi.c:2106:istgt_iscsi_op_login: ***ERROR*** access denied

Slightly confused at this point, I decided to DETACH the ISCSI SR(s) and REATTACH which resolved the issue. Not sure why this happened? Anyone?