Re: Visibility of SAN LUNs

Brado23 · ‎09-05-2007

I have set up some ESX 3.0.1 systems (with all current patches) connected to a Hitachi NSC55 SAN via QLogic QLA2340 HBA's (1.52 firmware) and am having issues with seeing newly presented LUNs after a rescan. My situation is as follows:-

Click on rescan after LUN's are been presented -> Nothing appears

Reboot ESX server then click on rescan -> I can see all available LUNs

Disable SAN switch port, then reenable -> I can see new LUNs (I believe this forces the HBA to relogin)

If the SAN guys remove a LUN that was presented, I can click on rescan and the removed LUN disappears (without modifying the switch port or rebooting the ESX server). If they re-add this same LUN I can click re-scan and it re-appears. Anything new however, needs either an ESX server reboot or SAN switch port disable/re-enable.

I have tried rescans from both the VirtualCenter GUI and from the Service Console.... the result is the same.

In addition to above, after setting everything up (VMFS datastores and multipathing settings) I then reboot the ESX server and when it comes back up there is no SAN disk visible until I manually click on rescan again. All of the settings I configured prior to the reboot are lost. This is obviously a major problem.

Has anyone seen this behaviour before. Does anyone have any ideas on what may be causing this?

Any help is much appreciated.

Thanks,

Brad

titaniumlegs · ‎09-05-2007

QLogic cards need to rescan twiceto see new LUNs.

http://kb.vmware.com/selfservice/dynamickc.do?cmd=show&forward=nonthreadedKC&docType=kc&externalId=1...

Stumped me the first time too!!

Share and enjoy! Peter If this helped you, please award points! Or beer. Or jump tickets.

christianZ · ‎09-06-2007

Check this:

http://www.vmware.com/community/thread.jspa?messageID=649415&#649415

titaniumlegs · ‎09-06-2007

I think these are all different problems.

\- Boot times while it scans LUNs

\- Optical noise from QLogic cards during boot/shutdown confusing switch ports

\- Having to rescan twice to see LUNs when ESX is already running. (This thread).

Share and enjoy! Peter If this helped you, please award points! Or beer. Or jump tickets.

Brado23 · ‎09-06-2007

Hi Guys,

Thanks for your responses.

I should have mentioned that I have tried about 10 rescans in the GUI and it doesn't make any difference. I have not tried running the cos-rescan.sh script. Where do I find this? I'll give it a try as soon as I know.

The biggest issue for me right now is the LUNs disappearing after a reboot. Is this information written to a file somewhere when it is setup? Is it possible that this is not being saved due to permissions on some file which is resulting in it being lost after a reboot?

Thanks again,

Brad

Brado23 · ‎09-06-2007

Some extra information about the disappearance after reboot issue....

If I run cat /proc/scsi/qla2300/0[/b] and cat /proc/scsi/qla2300/1[/b] the 7 LUNs that I should be able to see are listed in there. However, if I run cat /proc/scsi/scsi[/b] it is empty on a problem system. I checked a different system that can[/b] see it's LUNs and /proc/scsi/scsi is populated similiar to below:

Attached devices:

Host: scsi1 Channel: 00 Id: 00 Lun: 01