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DPM 2016 not releasing storage RRS feed

  • Question

  • We're on DPM 2016 Version 5.0.409.0

    We've got a B1200i Drobo iSCSI attached to our DPM server. It is set up as 3 disks in the DPM Storage Pool. DPM is showing 24,856 GB of drive space allocated and only using 12,000 of that.  The Drobo software is showing 29.99 TB of 34.71 used. 

    Why is there such a discrepancy between what DPM has allocated and what our Drobo is using? It's about a 5 TB difference. It's been this way for about 5 days so I was expecting the nightly tasks to clean this up.  I've also manually ran pruneshadowcopiesDpm.ps1 and it made no difference.  I'd like to avoid adding more disks if possible considering DPM is only storing 12 TB of data. A 34.71 worth of storage should be plenty.  Is there anything I can do to free up space on my existing disks?

    Tuesday, April 30, 2019 1:44 PM

Answers

  • DPM 2016 and DPM 2019 uses Modern Backup Storage (MBS), both DPM 2016 & 2019 accepts volumes  (earlier DPM versions used disks, not volumes) for storage.

    Once you add a volume, DPM formats the volume to ReFS to use the new features of Modern Backup Storage.

    Volumes cannot reside on a dynamic disk. Use only a basic disk.


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    • Marked as answer by ImmaNeedSpace Tuesday, April 30, 2019 9:10 PM
    Tuesday, April 30, 2019 8:47 PM

All replies

  • Hello,

    I cannot say anything about your third party software as it’s unfamiliar to me.

    DPM will not unallocate disk space on it’s own, if the allocated disk space on a recovery point volume is less then what it used to be, you can shrink the volume by modifying the disk allocation.

    Best regards,

    Leon


    Blog: https://thesystemcenterblog.com LinkedIn:

    Tuesday, April 30, 2019 2:54 PM
  • Thanks Leon. Yes I have done that. I went through all of our protection groups and shrank all the volumes DPM would let me shrink. It did increase the % Unused in Disk Storage  but did not change the amount reported by the Drobo software. diskpart is also showing the 3 Drobo disks as having 12 TB free. Perhaps it is an issue with the Drobo software.


    Tuesday, April 30, 2019 4:01 PM
  • One way to find out is by comparing the results between different software.

    You could check if WinDirStat shows the same results.


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    Tuesday, April 30, 2019 4:04 PM
  • I tried WinDirStat and it cannot see the 40 TB SAN that is iSCSI attached to the server. They are attached as Dynamic NTSF disks.

    Would DPM 2016 have any issues with Dynamic drives?  This is an in-place upgrade from DPM 2010 / Server 2008 to DPM 2016 / Server 2016.

    Tuesday, April 30, 2019 8:11 PM
  • DPM 2016 and DPM 2019 uses Modern Backup Storage (MBS), both DPM 2016 & 2019 accepts volumes  (earlier DPM versions used disks, not volumes) for storage.

    Once you add a volume, DPM formats the volume to ReFS to use the new features of Modern Backup Storage.

    Volumes cannot reside on a dynamic disk. Use only a basic disk.


    Blog: https://thesystemcenterblog.com LinkedIn:

    • Marked as answer by ImmaNeedSpace Tuesday, April 30, 2019 9:10 PM
    Tuesday, April 30, 2019 8:47 PM
  • Leon, Thank you. Dynamic Disks seem to be the issue both from a DPM standpoint from what you've said here,  and also from what Drobo support is telling me. Thank you for the help.
    Tuesday, April 30, 2019 9:11 PM
  • You're welcome!

    Blog: https://thesystemcenterblog.com LinkedIn:

    Tuesday, April 30, 2019 9:15 PM