Replica disk threshold exceeded, or Recovery Point Volume threshold exceeded

Great! :(  Now what?

Well, if you have a new DPM server and not a lot of protection groups created, and you haven’t been protecting anything much, you can just click on the link in the warning message that says “Allocate more disk space for replica…”  That pulls up a pretty window that looks like the one below:

image

So you go ahead an make the number in the “Replica Volume” field a little bigger, hit ok and go on about your business.  Unless..

Sometimes you may need to go and use DISKPART to manually add space to the volume.  If you try the above method, and you get a failed message instead of success, you are either out of disk space, or it could be that you have more than one disk on your DPM server and one of the disks becomes full.  In order to extend the volume onto another disk, you have to use DISKPART.  DPM (at this version) won’t do it for you.

  1. Open a command prompt (run as administrator if you are using a 2008 Server for your DPM server) and type “diskpart”. 
  2. Type “List Volume” at the prompt.
  3. Right click and “select all” then enter to copy the output to the clipboard
  4. Paste it in notepad so you can do a search and search for the Data Source
    1. You should see a line similar to this:

        Volume 534       DPM-Prolo  NTFS   Simple      2050 MB  Healthy
          C:\Program Files\Microsoft DPM\DPM\Volumes\Replica\SQL2.domain.com\ SqlServerWriter\PrologPilot\
        Volume 535       DPM-Prolo  NTFS   Simple      2050 MB  Healthy
          C:\Program Files\Microsoft DPM\DPM\Volumes\DiffArea\SQL2.domain.com\ SqlServerWriter\PrologPilot\
        Volume 536       DPM-Non VSS  NTFS   Simple      1540 MB  Healthy
          C:\Program Files\Microsoft DPM\DPM\Volumes\Replica\quick1.domain.com\Non VSS Datasource Writer\Computer\SystemState\SystemState

    1. The volume number  comes before what it is describing and there are 2 for each protected object.  A Replica volume and a DiffArea.  The replica volume is a copy of the data as it is on the protected member.  The DiffArea is where the recovery points are stored.  The “Non VSS Datasource Writer” is system state in the example.
  5. At the DISKPART> prompt type “select volume” and the volume number i.e. : select volume 534
  6. If you want to see the details about the disk, you can type detail volume and it gives an output similar to:

    DISKPART> detail volume

      Disk ###  Status      Size     Free     Dyn  Gpt
      ——–  ———-  ——-  ——-  —  —
    * Disk 2    Online      2560 GB   356 GB   *    *

    Read-only              : No
    Hidden                 : No
    No Default Drive Letter: Yes
    Shadow Copy            : No
    Dismounted             : No
    BitLocker Encrypted    : No

    Volume Capacity        : 1030 MB
    Volume Free Space      :  186 MB

  7. In order to increase the space for the Replica volume you would type: EXTEND SIZE=1024 DISK=2.  This would extend the selected volume by 1 GB (1024 MB) on DISK 2. 
  8. Now you have to go back in and tell DPM that you extended the volume.  (I believe it may figure it out on its own eventually, but I prefer to get the warning cleared up sooner rather than later, so I go update DPM.

 

Note:  Each time you use DISKPART, you are likely to see different numbers for the volumes.  I haven’t looked into what that is, but I do know that the system volume is always one of the last in the list.  For that reason I recommend that you always view detail volume after you select it, to make sure you are seeing the volume you intend to work with.

4 comments

  1. I’m familiar with the process of making the recovery point volume a little bigger, but sometimes I can’t make sense of *what* has exceeded the 90% threshold. For instance, right now my “data size” is 1.47GB, my “Replica Volume” is 1.85GB, and my “Recovery Point Volume” is 11.52GB, and yet it tells me to allocate more disk space for the *recovery point volume*. Why? What has “exceeded the 90% threshold”? I want to understand how it is making this calculation.

    1. Dan,

      DPM creates two volumes for each protected item (database, VM, file share, etc). The first volume is the Replca Volume. This is where DPM stores the most recent recovery point view of the protected member. The other volume is the Recovery Point Volume. This is where the historical changes are saved. Depending on what you are protecting, how long you are protecting it, how often you create recovery points, and how much data change there is between recovery points, the Recovery Point Volume can be many times the size of the Replica Volume. In my experience, active Databases and System State are the most space consuming. Large file servers tend to have much less churn.
      Hope this helps.

      Michael

  2. Michael, Thanks for your response. The part about the RPV having the potential to be many time the size of the replica volume is particularly helpful.

    Is the bottom line that the system internally calculates the 90% threshold and that DPM admins won’t always have access to the figures the system used in that calculation?

    1. Essentially, all DPM is doing is looking at the used space for the Recovery Point Volume. The only problem I have seen with this is when DPM 2007 had the issue where it wouldn’t remove expired recovery points. I posted about that here: http://nukeitmike.com/blog/2009/04/12/dpm-does-not-remove-expired-recovery-points/ and a follow up to that here: http://nukeitmike.com/blog/2009/08/07/follow-up-to-the-dpm-recovery-point-expiration-issues/

      Hope this helps.

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