iSCSI connection problems in ESXi 5.0

Disable Interrupt Remapping in ESXi 5.0

If you're running ESXi 5.0 and DSS V6 build 5845 (version:
6.0up90.8101.5845) and you are experiencing issues with iSCSI connections and
drop outs for short periods of time and the following alert appears in the
vmkernel/messages log files:
ALERT: APIC: 1823: APICID 0x00000000 - ESR = 0x40

Try the follow to disable the Interrupt Remapping on ESXi 5.0 side:

1). On all the ESXi 5.0 node’s disable VT-D setting in the bios
2). In ESXi 5.0 console type: esxcli system settings kernel list -o iovDisableIR

More information can be found from the link below :
http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&externalId=1030265&sliceId=2&docTypeID=DT_KB_1_1&dialogID=274206354&stateId=0%200%20268832559

VMware has confirmed there is a problem and a patch will follow next quarter of this year 2012.