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Disk Usage Much Higher After Running Migratedatasourcedatafromdpm RRS feed

  • Question

  • I'm using DPM 2010 on Server 2008 R2 SP1.

    I had a 2.6TB internal volume which held a about 2.2TB worth of assorted replicas. I also have a 15TB SAN volume for other replicas attached to the machine as well. I believe the 2.6TB disk had approximately 5 spanned volumes which had minimal space used on the 15TB SAN Volume.

    To allow for future backup expansion I attached another 10TB volume from our SAN to our DPM server; this gave me 25TB total space allocated to backups. I then ran MigrateDataSourceDataFromDPM to move the full volume worth of replicas from the 2.6TB disk to the 10TB disk.

    For some odd reason the original 2.2TB worth of replicas are now taking up more than 9.4TB on the new volume. Can anyone explain this behaviour to me? The few volumes spanned across the original 2.6TB and 15TB volumes took up nowhere near that kind of space, and if they had, should that space now be freed up on the 15TB volume?

    As it stands the original congifuration gave me 17.6TB allocated with approximately 900GB free. The new configuration should have given me 25TB allocated with approximately 7TB free. Instead I have 25TB allocated with approximately 1.1TB free.

    I have done my due diligence and added up the space taken by each of the protection groups and it only reaches 17.5TB so there's approximately 7.5TB missing somewhere.

    Thanks for your Help.

    Wednesday, January 18, 2012 5:52 PM

Answers

  • When you did the MigrateDataSourceDataFromDPM did you use the disk to disk option or the datasource to DPM disk option.

    If you look at the details of a couple of the protected sources you should see the relevant volumes associated with each data source. Are these the same size as the volumes previously?

    When you do a MigrateDataSourceDataFromDPM the original replica and recovery point data is kept until the recovery points expire.

    From http://technet.microsoft.com/en-us/library/dd282970.aspx
    "The MigrateDatasourceDataFromDPM script moves all data for a data source or disk to the new disk or volume. After migration is complete, the original disk from where the data was migrated is not chosen for hosting any new backups. You must retain your old disks until all recovery points on them expire. After the recovery points expire, DPM automatically deallocates the replicas and recovery point volumes on these disks."

    Is the 7.5TB of space the addition of the old replica AND recovery point volumes that have not yet expired?

    • Marked as answer by TheWaker Friday, January 20, 2012 9:16 PM
    Thursday, January 19, 2012 1:39 AM
  • Hello,

    Yes, you are correct. Once the recovery points expire, the disk will be reclaimed.

    The reason for this is in case you wish to perform a recovery of that data.


    Thanks

    Shane

    • Marked as answer by TheWaker Friday, January 20, 2012 9:16 PM
    Friday, January 20, 2012 7:53 PM

All replies

  • When you did the MigrateDataSourceDataFromDPM did you use the disk to disk option or the datasource to DPM disk option.

    If you look at the details of a couple of the protected sources you should see the relevant volumes associated with each data source. Are these the same size as the volumes previously?

    When you do a MigrateDataSourceDataFromDPM the original replica and recovery point data is kept until the recovery points expire.

    From http://technet.microsoft.com/en-us/library/dd282970.aspx
    "The MigrateDatasourceDataFromDPM script moves all data for a data source or disk to the new disk or volume. After migration is complete, the original disk from where the data was migrated is not chosen for hosting any new backups. You must retain your old disks until all recovery points on them expire. After the recovery points expire, DPM automatically deallocates the replicas and recovery point volumes on these disks."

    Is the 7.5TB of space the addition of the old replica AND recovery point volumes that have not yet expired?

    • Marked as answer by TheWaker Friday, January 20, 2012 9:16 PM
    Thursday, January 19, 2012 1:39 AM
  • Hello,

    Yes, you are correct. Once the recovery points expire, the disk will be reclaimed.

    The reason for this is in case you wish to perform a recovery of that data.


    Thanks

    Shane

    • Marked as answer by TheWaker Friday, January 20, 2012 9:16 PM
    Friday, January 20, 2012 7:53 PM
  • Thanks for the information. I'll let the replicas expire and post again only if the space is not reclaimed.
    Friday, January 20, 2012 9:17 PM