BAD BAD CLUSTER - NEED TO REMOVE and RESTART - Some Valued Opinion

Discussion in 'Clustering' started by Simon, Feb 28, 2007.

  1. Simon

    Simon Guest

    Hello everyone
    Base setup for your info:

    2 x Node Cluster Win2k3 SP1
    Each Node has "Veritas Storage Foundation" installed and configured. This
    application was to make basic disks into dynamic, integrate into the cluster,
    allow you to change disks on the fly, increase, decrease size, ect! It does
    other stuff, but in my opinion and experience, its been a HUGE HUGE
    nightmare!!!!
    The disks are created from a HP EVA SAN Based Solution - Currently each node
    acts as a FILE SERVER and hosts 8 disks.

    PROBLEM: Need to remove the cluster and rebuild. BIG PROBLEM: The Veritas
    Storage Foundation Software appears to have made a "signature" on these disk
    volumes. It means, that they cannot be presented to any other windows server
    system, unless we install the Veritas software on another box!

    We DONT want this software - its been the clusters problem all along, and I
    need to get shot of it.

    Trouble is, does anyone have any experience of this product, more so, is
    there a way to "release" these disks so that a bog standard Win2k3 Server can
    see the disks and treat then as just disks that contain data. At the moment,
    when these disks are presented to any other server, they are known as Foreign
    and Windows wants to blat them :)

    As they contain TB of data, its not an option.

    WORSE CASE: Create brand new disks from my EVA, basic, restore data from
    backup tapes (which is long and hard, but can be done). Dont want to try this
    just yet. Hence, any opinions are welcome.

    I am sure the Veritas product is good ... in my professional view.... trying
    to make a basic disk into dynamic and making it sing and dance is not what I
    wish to achieve.

    And whats wrong with Diskpart - something I have used all the time and will
    continue to use to change my disk size.

    Cheers
    Simon
     
    Simon, Feb 28, 2007
    #1
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  2. Simon,

    I understand the pain.... and I have experienced some "interesting" behavior
    with Veritas on Clusters as well, and to-date, uninstall Veritas was
    definitely my preferred solution for these mis-behaviors. MSCS can only take
    basic disk for clustered disk resources.

    You are facing a dillema, not really signature related, but you are having
    dynamic disks created by Veritas, and you want to move to basic disk, so
    here goes

    If you have a "Simple DynamicVolume" which is a dynamic volume on one
    physical disk, you can convert back to basic, without data-loss.

    If you have a "Mirrored Dynamic Volume" which is 1 dynamic volume, mirrored
    on two physical disks, you can convert back to basic.

    If you have any other form of dynamic disk, such as "Spanned volume" or
    "Striped volume" you can NOT convert back to basic.

    Although you can convert some dynamics; I would strongly recommend you
    commission new disks from your storage, and do a data-migration. Just for
    the fact that you will start with fresh new NTFS basic volumes for your
    cluster.

    It is a bit of pain to go through, but if you carefully plan, with help of
    your storage vendor to help you with the commission of new disk and
    migration of data, you probably will benifit of a more stable system in the
    long run.

    Rgds,
    Edwin.
     
    Edwin vMierlo, Feb 28, 2007
    #2
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  3. Simon,

    be carefull with terminology here, I do not think this is a problem with
    "disk signature" as Microsoft's definition of this. I do believe however
    that this is a problem with the LDM database (as written to the last 1MB of
    the disk, just outside the partition boundary).
    This database holds the information for the dynamic disks. Although similar
    as standard Microsoft dynamic disk, there are distinct differences in the
    Veritas LDM database, especially in the terms of "Dynamic disk group names".

    Not as simple for clustered nodes, but on standalone systems, if you remove
    Veritas, and your OS sees the disks as "Foreign" that means that the OS
    recognises the disk as being dynamic. You can right-click and import them as
    microsoft dynamic disks.

    If they are not listed as Foreign but listed as "New" or "unallocated", then
    I would suggest to involve Microsoft PSS to investigate how to bring back
    those disks (and data !) into your system. This probably involves
    "dmdiag.exe -v" and "dmpss.exe". The first one is a reporting tool, the
    second one is a tool experts use to fix LDM problems on dynamic disks. Do
    not try to run dmpss.exe yourself, as you can loose all data permanently, if
    you are not careful !

    Still, I think your best option is to present new (basic) disks, do a data
    migration (obviously Veritas need to be installed, you need to copy data
    from the Veritas dynamic volumes to the basic disks) and bring the new basic
    disks into your cluster.

    Rgds,
    Edwin.
     
    Edwin vMierlo, Feb 28, 2007
    #3
  4. Simon

    Simon Guest

    Hi Edwin
    Yes the terminology in regards to the signature, is what is written to LDM.
    But in all honesty, if its going to be easier to migrate these disks onto new
    basic disks and restore all data from a good tape backup, so be it !

    Without sounding negative..... is there people that actually used this
    product in a clustered environment (I know it supports clustering, as its
    licensed for it!)

    Cheers, simon
     
    Simon, Feb 28, 2007
    #4
  5. yes, I have used it, and I have uninstalled it.
    My personal experience is not so good with this product.

    Rgds,
    Edwin.
     
    Edwin vMierlo, Feb 28, 2007
    #5
  6. Simon

    NuT CrAcKeR Guest

    My experience with this product has been absolutely blissful. I love using
    it with clusters and it makes data and SAN Migrations a breeze. I have not
    been faced with the need to ever remove it up to this point. I wish ALL my
    customers SAN attached servers had this installed. Truely, I do !

    I have more than 80 clusters, but fewer than 30 have VSFW. I am in the midst
    of a massive migration from old Symmetrix frames, to new DMX frames.
    Sometimes we have to robocopy to new disks, other times we use EMC's
    OpenMigrator. But I simply LOVE doing the veritas clusters. Its such a
    breeze, and my disks offline in fewer than 5 seconds, and come online just
    as quickly.

    - NuTs
     
    NuT CrAcKeR, Mar 10, 2007
    #6
  7. Obviously, it is a personal thing. For myself, I would never recommend it to
    a customer. I am a stout believe in keeping things as simple as possible,
    and thus easy to support.


    --
    Russ Kaufmann
    MVP - Windows Server - Clustering
    ClusterHelp.com, a Microsoft Certified Gold Partner
    Web http://www.clusterhelp.com
    Blog http://msmvps.com/clusterhelp
     
    Russ Kaufmann [MVP], Mar 12, 2007
    #7
  8. You might be the first person I've ever heard make this statement
    (enjoying/recommending VSFW). I personally would avoid it at all costs. It
    makes troubleshooting cluster issues more difficult and impossible to
    interpret cluster logs without assistance from the vendor.

    Regards,
    John
     
    John Toner [MVP], Mar 14, 2007
    #8
  9. Simon

    Simon Guest

    Hi Nuts / John / Russ
    Firstly for Nuts ... you really MUST be nuts!!!! :) Seriously, this is a
    TERRIBLE terrible product! In fact, after visiting the Symantec Forums, its
    absolutely amazing just HOW much trouble this application causes.

    And once you extend a disk with the VEA, you are totally reliant on this
    software.

    I am with Russ and John - Keep your clusters as SIMPLE as possible - why
    make a Basic disk Dymanic? The fact is, Basic disks is all you need, and you
    can use diskpart to extend it.

    But if you are pleased with the product, then good for you ... .as for me
    and many other people.... you either love it or hate it ... and for the cost
    of the software, I could implement better solutions and put the money to
    better effect.

    Thanks, Simon
     
    Simon, Mar 15, 2007
    #9
  10. Simon

    NuT CrAcKeR Guest

    Yah, Im NUTS like fox ...

    You are correct about your volume dependency on VEA once you create them ...
    unless you check the option to keep them compatable with Windows Disk
    Managment while creating your dynamic disk group. The only place (where i
    work) that i have seen any kind of issue with that has been during
    discussions about virtualization. The fact is, the servers I have that use
    VSFW arent the kinds of boxes you would want to virtualize anyway, so it
    really not an issue for us at all.

    - NuTs
     
    NuT CrAcKeR, Mar 16, 2007
    #10
  11. Simon

    Simon Guest

    Hi Nuts
    Thanks for the reply - Although I can apprecaite your liking for it, there
    does clearly seem to be a problem - I do not believe I am the only one that
    appears to have been caught out, but in anycase, what I am in the process of
    doing is creating new basic disks, outiside the scope of VEA and eventually
    restore the data back to them and remove the disks that are part of the disk
    group in VEA.

    Hopefully should solve the problem. We also do virtual clusters, and as part
    of a test, created an identical cluster config with the VEA, and found we
    still had similar issues. I am not sure why this product was in use, because
    it has only added an extra layer of complexity behind what should be .. a
    simple file cluster :)

    Thank you for your time :)
    Simon
     
    Simon, Mar 16, 2007
    #11
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