Recently we have some serious problems on a small project implementation.
We had 2 Cisco UCS C200 M2 servers, 2 Cisco MDS9148 and a EMC VNX5100 storage array.
The servers used Qlogic 8GB Fiber channel cards. The problem appeared always on heavy storage use (backup tasks mostly), but it could be once a week.
When accessing to the esxi console you could write user and password but you could not enter.
After that you needed to restart the Esxi and Virtual Machines were down.
I opened a SR on VMware but solved the problem before they answer.
After looking at vmkernel.log I searched on Google for info about errors appearing and finally I founded a KB Article that was very interesting:
vHBAs and other PCI devices may stop responding in ESX/ESXi 4.1 and ESXi 5.0 when using Interrupt Remapping
Also I founded at Vmware communities some threads with same case:
http://communities.vmware.com/message/1983041 (Cisco servers)
http://communities.vmware.com/thread/341512 (IBM, Supermicro)
We execute the actions in the KB and everything is working fine after 20 days.
Hope this helps others on searching solutions!!
