How to expand a software RAID5 on WHS? RRS feed

  • Question

  • Hi folks.
    I've had a look through the forum and can't find an answer to this one.

    I currently have 4 x 2 TBs disks set up on WHS in software RAID5.
    I now need to expand the RAID array and have an additional 2TB drive that I want to add.
    Is there a simple way to do this without losing all my current data on the RAID?
    I'm running WHS1 and not the 2011 release.

    Thanks in advance

    • Moved by Ken WarrenModerator Thursday, June 21, 2012 10:45 AM V1 question (From:Windows Home Server 2011)
    Wednesday, June 20, 2012 6:38 PM

All replies

  • Why are you using software RAID with WHS1. One of the benefits of WHS1 over WHS2011 is that it had Drive Extender which allowed for file duplication across drives and the simple addition of extra hard disks as you began to run out of space.

    As for your question, that's not really a WHS question - what software RAID are you using?

    Phil P.S. If you find my comment helpful or if it answers your question, please mark it as such.

    Wednesday, June 20, 2012 7:49 PM
  • Windows doesn't offer any means to expand RAID capacity, I'm afraid.

    Two workarounds come to mind.

    1. Back up the data on the volume.
    2. Recreate the array with the added disk.
    3. Partition.
    4. Restore your data.

    Or the preferred option:

    1. Back up the data on the volume.
    2. Purchase a RAID HBA which supports your drives.
    3. Connect the drives to the new RAID HBA.
    4. Create a RAID 5 volume.
    5. Partition.
    6. Restore your data.

    I recommend you review the information available on Technet concerning software RAID and how to manage it.

    I'm not on the WHS team, I just post a lot. :)

    Thursday, June 21, 2012 1:01 AM
  • Thanks for your feedback guys.
    You've both confirmed what I suspected.

    I think the route I'll take will be to back up my data to that, and then reconfigure the WHS drive and just use Drive extender so that I can add extra drives as I need them.  I'll then use an external E-SATA Raid box like the Lian-Li EX-503 for RAID.


    Thursday, June 21, 2012 8:26 AM
  • One final note: I hadn't noticed that your question related to V1 (and I'll be moving it to the appropriate forum shortly). Drive Extender is incompatible with dynamic disks, which are required for Windows RAID. On a V1 server, you must use a RAID HBA rather than software RAID.

    I'm not on the WHS team, I just post a lot. :)

    Thursday, June 21, 2012 10:45 AM
  • Hi all,

    I had the same problem (not able to expand a Windows RAID-5 array),

    I ended up writing a program that does the trick (expand an NTFS partition on a dynamic RAID-5 volume),

    it also has the ability to recover from a drive failue during the expansion process,

    Both my program (Dynamic Disk Partitioner) and it's source code are available here:


    You should test it on a smaller scale before using it. Be sure to back up all of your important data.

    Tal Aloni

    • Edited by Tal Aloni Saturday, December 31, 2016 11:58 AM
    Sunday, July 15, 2012 7:48 PM