re-configuring SBS2003 server - advice needed please

Discussion in 'Windows Small Business Server' started by Alex H, Feb 25, 2005.

  1. Alex H

    Alex H Guest

    Hi

    We have a Powerdge 1750 server running SBS2003. Al though the server has
    three HDU bays, at present the server is configured with Raid5 and two x
    36GB mirrored SCSI drives. The drives are split 8.75GM System, (C drive)
    and the remainder as data (D drive)

    We are surely running out of space and need to increase drive capacity. We
    seem to have a number ofoptions, but we are looking to use 2 or 3 72GB
    drives.

    The favourite at the moment, is to replace the two 36GB drives, with three x
    72 GB drives and do a total rebuild, which presumably would give us 100GB
    capacity mirrored.

    I would appreciate the opinions of this forum as to the best way to achieve
    the addition of the extra space ( if possible without a rebuild)

    Thanks

    Alex
     
    Alex H, Feb 25, 2005
    #1
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  2. Something doesn't sound right here. If you have RAID5 you have to have at
    least 3 drives. If you only have 2 drives you more than likely have RAID0
    (mirroring). I don't believe you can "rebuild" your array onto all new
    drives. My understanding of RAIDs is that with RAID5 if you have one of the
    3 drives fail, you simple replace it with the same model drive and you can
    rebuild without ever shutting the system down. RAID0 on the other hand is
    simply two copies of the same thing, one drive fails and you rebuild it
    with the copy off the other drive. (redundancy)

    You could just add another HD (E Drive) and move data to it. Or go with NAS
    (network attached storage) which is basically a hard drive with a network
    interface.

    HTH
    Jon W
     
    Jonnie FoxPro, Feb 25, 2005
    #2
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  3. Alex H

    Alex H Guest

    Ho Jon

    Sorry getting myself into a muddle already. yes we have a Perc 4 controller
    with Raid0 - sorry about the misinformation.
     
    Alex H, Feb 25, 2005
    #3
  4. Alex H

    Alex H Guest

    Sorry everyone getting confused already. We actually have Raid0

    Alex
     
    Alex H, Feb 25, 2005
    #4
  5. Do you have two 36 GB drives in a mirror set? If so, you'd see 36 GB of
    total capacity and you'd be running Raid 1, where one drive is a mirror of
    the other. That provides redundancy in case one drive fails. Raid 0 is
    where your data is striped across the two drives for performance. In the
    case of Raid 0, your two 36 GB drives would have 72 GB total capacity but no
    redundancy.

    I'm assuming you have a mirror (Raid 1), which is what Dell would have
    recommended to you when you bought the server. I believe the 1750 supports
    up to 6 drives, right? In that case, I'd leave the 36 GB mirror in place
    and configured as is. I'd use the existing ~8 GB partition for the OS, and
    I'd put your Exchange Server data on the existing ~25 GB D partition. This
    has the benefit of leaving the OS where it is, and not requiring any
    reconfiguration of the existing array. It also lets you continue to use
    those working, paid-for drives.

    Then, I'd add 3 drives of whatever size works for you, in a Raid 5 array.
    If this is the server I'm thinking it is, you should have space to add four
    more drives. If you add 3, you'll have double the capacity of one drive
    (raid 5 uses one drive for parity, which is what gives you the redundancy).
    If you add 4 drives, you'll have triple the capacity of one drive. Then you
    can partition the space into one or more partitions - whatever works for
    you.

    You can get the drives from Dell or elsewhere. Dell will cover them under
    the server's warranty, but they're probably available cheaper - it's up to
    you. If you have the regular Dell SCSI backplane, remember that you will
    need drive carriers and screws. The carriers will have to come from Dell,
    and hopefully they'll sell you the screws at the same time. When everything
    arrives, I would do a full, verified backup. Then, call Dell server support
    and tell them what you're doing. Let them walk you through the installation
    process and the Raid configuration right over the phone. Not sure about
    Dell in the UK - here in the US, I always do this stuff on a Saturday, when
    my office and Dell support are both slow.
     
    Dave Nickason [SBS MVP], Feb 25, 2005
    #5
  6. like he said BUT...

    I'd throw four drives in, but I'd do a 3*70 RAID5, 140GB usable, and keep
    the fourth drive as a hotspare. I'm fairly certain it will operate as a
    hotspare for both arrays.

    I think there's a slight complication if the 70G gets incorporated into the
    36G RAID1 and you wish to later use it in a 70G role but I may be thinking
    of either an earlier PERC or the Compaq controllers.
     
    SuperGumby [SBS MVP], Feb 25, 2005
    #6
  7. Alex H

    Alex H Guest

    Dave Hi and thanks foryour post. As you can see this RAID studff is very
    new to me.. but you do think I'd know what we bought from Dell and how my
    own system is configured....

    yes you are right, we have two x 36Gb drives and yes I see total of 36Gb.

    The 1750 is a 1U rack mount server, so no, I have a max of three drives
    internally,so I can onyl add one drive internally. have been told that I
    could buy a PowerSTorage external box and fill it with more drives, and
    connect that back to my 1750

    Yes,you are right,I'd like to continue using the paid for drives if
    possible.

    A
     
    Alex H, Feb 25, 2005
    #7
  8. Excellent point. All three of my PE servers had drives fail over to their
    hot spares in 2004, including one that was about 7 months old.

    With PERC controllers, it's the "global hot spare" option that lets one
    drive cover for both arrays. "Dedicated hot spare" is where the drive is
    assigned to one specific array. Some of the older PERCs don't support
    "global."
     
    Dave Nickason [SBS MVP], Feb 25, 2005
    #8
  9. OK, I also thought you had more drive space, but so be it, three bays.

    Which PERC controller is it? _-*exactly*-_ . Many support migration from one
    RAID level to another.

    the plan would be to pop one of your mirrors and replace it with a 70G HDD,
    rebuild the array, pop the other drive, replace it with a 70G, rebuild the
    array, add the third drive and migrate the array from RAID1 to RAID5.

    BUT FIRST WE NEED TO CHECK THAT THE SPECIFIC CONTROLLER ALLOWS THIS PROCESS.

    If it went pear shaped at any point you would fallback to the first drive
    you removed.
     
    SuperGumby [SBS MVP], Feb 25, 2005
    #9
  10. Alex H

    Alex H Guest

    So if I did a rebuild/install with 70GB drives, I could set that up in my
    1750?

    Alex
     
    Alex H, Feb 25, 2005
    #10
  11. Alex H

    Alex H Guest

    I'm out of office at moment. I've VPN'd onto server and can see that its a
    Perc4. I believe it was a LSI Logic PERC 4/Di

    Sounds fun !!

    Alex
     
    Alex H, Feb 25, 2005
    #11
  12. Alex H

    JWMay Guest

    Alex,

    I just did this today on one of my customers’ server. Get a new controller
    with the new drives, load the new controller drivers to the existing
    installation, shut down and install the new controller and drives, reboot and
    configure the new mirrored set, continue booting to a Norton Ghost boot disk
    and ghost your OS from the old container to the new container, shut down and
    remove the old drives and controller, reboot again and check your BIOS for
    the correct configuration, continue booting and you should be set.

    JWMay
     
    JWMay, Feb 25, 2005
    #12
  13. SuperGumby [SBS MVP], Feb 25, 2005
    #13
  14. Alex H

    JWMay Guest

    Sorry, didn't see that you were maxed at three drive bays. Maybe the
    external drive bay would be a good option.
     
    JWMay, Feb 25, 2005
    #14
  15. If he has two drives then I would suspect that they have a Raid1....not
    RAID0. Raid1 is a Mirror. Raid0 is a stripping.

    Raid1 is simply where you have two hard drives ( say, the two 36GB drives )
    but the NOS sees only one HDD ( well, not technically accurate but you
    hopefully know what I mean....the NOS will see only 36GB of HDD space ).
    This is because Drive0 is mirrored to Drive1. When a file is saved it is
    written to Drive0 and then Drive 1. If one of the HDDs crashes there is no
    problem. Simply replace it with another HDD and let the RAID Controller
    rebuild....Performance issues will be the result. But, you have lost no
    data ( assuming that only one HDD died ).

    Raid0 is stripping. There is no redundancy whatsoever. If one HDD dies
    then you have lost everything. In a Raid0 environment the NOS will see, in
    our example, 72GB of HDD space.

    Anyone who sets up Raid0 on a production server either does not know what
    he/she is doing or really does not care if everything is lost.

    I hope that the poster has a Raid1 and not a Raid0. What is of concern is
    that he does not seem to be very clear himself on what he has!

    --
    Cary W. Shultz
    Roanoke, VA 24014
    Microsoft Active Directory MVP

    http://www.activedirectory-win2000.com
    http://www.grouppolicy-win2000.com
     
    Cary Shultz [A.D. MVP], Feb 26, 2005
    #15
  16. Yes, you are in fact correct, he'd have a RAID1 (mirroring), or RAID0
    (Stripping) with only 2 drives

    Thanks for the Correction.

    Jon

    snip...
     
    Jonnie FoxPro, Feb 26, 2005
    #16
  17. Alex H

    Alex H Guest

    Hi Cary

    Went to office to confirm how machine was configured and yes it is raid 1
    mirroring, Drive 0 to Drive 1

    Alex
     
    Alex H, Feb 26, 2005
    #17
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