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VV id reservation

Posted: Wed Feb 22, 2012 7:25 am
by sid
For some of our procedures we need to retain the vv id (WWID) and keep it unique even though the vv (at any given point in time) may not be in existence (i.e. snaps). Is it possible to reserve a section of id's? I believe the answer to be no, but thought I'd see if anyone else had tried.

I was thinking a template which states "-i <10000" would mean all my vv's were created in the <10000 range allowing me to reserve 10000+ for snapshots etc. It wont let me do this saying it expects an non-negative integer.

Alternatively, it would be good if I could force it to 'reuse' id's on vv creation. It seems to increase the id number despite vv's being deleted when 'auto' is selected.

I notice the createvlun allows the LUN value to be in a given range but doesnt really do the job (as this is not the wwid of the vv)..

Re: VV id reservation

Posted: Sat Feb 25, 2012 12:58 pm
by Richard Siemers
That is an interesting problem. Out of curiosity, which app/os/process is sensitive to the WWN of the VV?

Perhaps refreshing/resynching the snaps instead of deleting and recreating might be a possible solution?

--Richard

Re: VV id reservation

Posted: Tue Feb 28, 2012 6:03 am
by sid
The problem is more to do with existing procedures transposed into the 3par world. With HP-UX each vlun wwid maps to a disk device file (/dev/disk/diskx). This is used in our scripts to create volume groups/lvs/file systems lvm. I did toy with the idea of recreating everything (wwid, device file, disks in volume) for each refresh but when you have 20+ going on different refresh schedules it got messy and I did break the process by having the same device file in 2 schedules.

I will look into the resync idea. Might be an option.