vmkernel log returns WARNING: SCSI: 2959: CheckUnitReady returned I/O error

[PiroNet]

Hi guys,
I have many ESX3.5U5 attached to an HP EVA8400 thru FC (Emulex). Vmkernel.log files log constantly the following message:

WARNING: SCSI: 2959: CheckUnitReady on vmhbax:y:z returned I/O error 0x0 / 0x2 sk 0x2 asc 0x0 ascq 0x0

Google is not help!
Found one single post in ITRC forum at http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1424294
It looks like a similar issue but still there is no fix/explanation :(

Also http://kb.vmware.com/kb/1003433 at VMware is no help neither.

Apparently the issue is fixed with vSphere but in the mean time I need at least an explanation of the issue.

Any comment welcome :)

Cheers,
Didier

[Jan Soska]

hello,
we faced similar assue after upgrading ESX3.5u4 to ESX4 with EVA6000.

Solution:
1) check/upgrade EVA firmware
2) check all ESX presented vdisks and set failover/failback and managing controller
3) check/change ESX multipath for each presented vdisk to RoundRobin (and set IOPS=1 acording HP-EVA-Vmware best practices)
4) upgrade your SAN fabric (in our case solved ports errors)

There are still some strange vmkernel logs, but according vmware support it is due too detailed logging planed to be fixed in future release of ESX or HBA ESX driver (in our case qlogic)

Jan

[PiroNet]

Hi Jan,

Thx for you answer and sorry for my late reply!

RR is not an option because we run ESX3.5 which is not ALUA aware anyway...

But I keep your other advices under the hood.

Cheers,
Didier