Currently, with OES 11 SP2 on SLES 11 SP3. When a SAN administrator presents a new lun or resizes and existing one to the server, the only way for the server to see the LUN change is for a reboot. This causes downtime and needless complexity to a simple task in windows. Netware was capable of doing this easily. This is more of a "SLES" issue, but since OES rides on top, this is the place for it
by: David G. | over a year ago | NSS
Comments
I think the linux command you are looking for is "/usr/bin/rescan-scsi-bus.sh". It can add new devices, remove devices, resize devices etc.
unless this has greatly improved, it has an issue if the volume is mounted from what I remember
Hmmm, I haven't ever tried to make a LUN bigger since it is so easy (and safe) to just add a new lun to increase the size of a pool/volume. However I did find this Novell TID - "HOWTO: Add, Resize and Remove LUN without restarting SLES or OES Linux" - that may hold the answer to your needs:
https://www.novell.com/support/kb/doc.php?id=7009660
been there, the OS never sees the lun unless we reboot, like I said, this functionality was cake in NW, just need to make it cake on OES
I agree, multi-path managment needs to work and be simple to operate...like Netware.
I am part of the NSS development team. We do the following things to rescan a new/existing LUN in our labs:
1) For LUN resize, use rescan-scsi-bus.sh --forcerescan
2) For new LUNs, I do 'echo "- - -" > /sys/class/scsi_host/hostX/scan' for all scsi hosts configured. Replace hostX with host0, host1 ... etc
3) In the rarest cases when 1) and 2) doesn't help, it generally is sufficient to do 'echo 1 > /sys/class/fc_host/hostX/issue_lip' before step 2)
If you find a chance to try these, please let me know your views. This being a user driven operation, it wouldn't be ideal for NSS or management tools to check for this every time for any new/resized LUNs.
The problem is that your competition (Windows) does everything through Disk Manager with a nice push button to rescan. Having a "user driven" operation or not, you are competing against simple push buttons and easier operation.
Ram K. It's nice that you have this rather intelligent procedure to go though, and it makes sense if you are linux familiar and have time to do it. How bout building all this into the scan devices button in imanager? or a scan for changes button? as Mike A. said, Windows does this easily, without cli interaction. Doing this on a ten node cluster with 60 luns is not an easy task, each of these 4 steps would means hours of keying. Make it simple, make it easy. I can deploy an app to 1000's of users in minutes using ZEN, but it takes hours to increase a drive size by 100GB
Sure, I will discuss this with the team and take it forward from there.