Best way to move a DST shadow pool

Hi all,

Does anybody have an best practice how to move a clustered shadow pool to a new storage device? E.g move the secondary pool from one iscsi target to a other.
Setup
2 node SLES10 sp4 OES2 sp3 cluster
DST setup
primary storage pool 150 GB pool on fc SAN
secondary storage pool 400 GB pool reside on Iscsi

object: To move the secondary storage to a new iscsi server with out losing any files or have all files moving back to primary storage, there is not enough space on primary storage to have all files there anyway.

Has somebody done this successfully?

Best regards

Lennart Johansson
  • Hey Lennart,

    We've just had to do something similar (had to move off an old san), but I decided to make life hard and create new volumes and use migfiles (miggui was hopeless on the cluster) to copy all the data over. I did Several Volumes and their shadows this way, and it took me bloomin' ages.

    But....... I then spoke to a novell tech about moving a seperate clustered nss object, and I really wish i'd spoke to him sooner. His suggestion was to mirror the partition (the one your shadow is on, assuming its only on one partition..) with a device on the new SAN. Let the mirror fully synch, then when you are done delete the old device off the mirror and run a tool to remove mirroring from the partition. It was soooo simple i nearly cried when I realised how many hours I'd put in. And because you're mirroring, you never have to take any resources offline.

    Before I tell you the steps, I have to point out "I am an idiot", please make sure you have a backup, because I honestly don't know what i'm talking about, its only because a novell tech talked me through something, that I have any clue. Also I never did this with a shadow, but having used migfiles for the better part of a month to copy files off of various shadows, I can't imagine it would be any different....but I can't guarantee it won't burst into flames the moment you try it....
    And I appoligise if the language is really noddy...its how I understand it.

    1.) Make sure all the nodes can see the new storage (we ran a discovery with iSCSI Initiator)
    2.) In NSSMU>Devices initialise the new device and make sure it is shared (F3
  • Hey Dave,

    Sounds like a good idea, I have a full backup and will give it a shoot later today.
    Will get back to you with result, we'll see if I'm unemployed by then :-)

    /Lennart
  • Hello Lennart

    I have personally used the method where you "shift" the data back and forth. Not quite as elegant as the NSS Mirroring, but it did work.

    However, as you pointed out, you have to have enough disk space to do this.

    Keep in mind that NSS Mirroring is on a partition level. In my case, we had "old" volumes that had been expanded numerous times, so I had like 23 partition segments and it would've been a nightmare to mirror all of those for one volume.
  • This is the second time i've typed this....stupid internet timeout.....

    Kevin is absolutley right. It is done at partition level.

    I am having a play at the moment mirroring a shadow, thats living on 5 seperate partitions (so 5 mirrors). I'll let you know how I get on, but it seems to be going ok so far.

    I've got my fingers crossed yours goes ok, I can't be the cause of someone loosing their job just before christmas :)
  • Hi Dave and Kevin
    It worked like a charm, I more or less followed the steps you pointed out.
    So now the old iscsi server is gone and the new one is the only one in the mirror set.
    Thanks a lot for all your help

    Best regards
    Lennart
  • Phew Glad to hear it, i've had a busy week this week, so didn't get a chance to check back, but in the back of my mind I was thinking "I hope Lennart's migration went alright" :)