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DPM 2010 BMR vs. local WSB RRS feed

  • Question

  • Consider this:

     - sample server with single 100GB drive (C:) with 50GB free space

    Now, when you do WSB backup locally to another partition (USB, whatever), you get (if you select the options) a single backup that contains everything including volumes/files and BMR. From this backup you can restore either individual files or volumes or do a BMR recovery.

    With DPM 2010, when you want be able to do both BMR recovery and restore individual files/volumes, then you have to select volumes and BMR independently, which leads to creation of (minimum) 4 volumes in DPM (drive C: replica + recovery volume, BMR replica + recovery volume).

    My questions are:

    1) why is DPM behaving like this and essentially wasting ton of disk space

    2) will this be "fixed" in future release

    In our real-world scenario, I'm backing up mere 4 servers. Total size of backed up volumes is 330GB (50, 80, 100, 100), real data less ofcourse. DPM allocates almost a 1TB for these 4 servers (volumes+BMR), which is ridiculous in my oppinion. What will happen if I add our additional 50-60 servers? We'll run out of SAN space VERY quickly.

    This is not about retention period or protection groups settings, this is about how DPM handles (duplicates) data. If DPM allowed file/volume recovery from BMR backup like local WSB backup does, then this would save lot of disk space on the DPM server.

    Thank you

    • Moved by Praveen D [MSFT] Monday, July 19, 2010 6:19 AM Moving DPM SS and BMR Protection Forum (From:Data Protection Manager)
    Wednesday, July 14, 2010 3:10 PM

Answers

  • Thanks for your valuable inputs. But technically that needs lots of changes to complete the scenario and the scenario is not that common. If possible we will consider it in future releases of DPM.
    Thanks, Praveen D [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, February 10, 2011 6:31 PM

All replies

  • Excellent question, MarkosP. Here are my observations...

    DPM does not let you recover a server's files or folders directly from the server's BMR backup. I agree that this is ridiculous and that it should be "fixed" in an update to DPM. I'm not holding my breath, though. I doubt this will get "fixed" until the next version of DPM.

    That being said, it is possible to restore files or folders from the BMR backup of a server. Steps:

    1. Restore the server's BMR backup to a local drive on the DPM server (faster), or to a drive on the protected server or some other server. Of course, the drive to which the BMR backup is restored must have sufficient free space.
    2. Start WSB on the protected server, choose Recover - A backup stored on another location - Remote shared folder - enter the UNC path to the BMR restored folders (either on the DPM server, local server, or another server) up to but not including the WindowsImageBackup folder - select backup date - Files and folders - choose file or folder to restore - specify destination.

    Thus, with some hassle, you can restore files or folders from the server's BMR backup that is stored on the DPM server. Obviously, this is far from ideal. If the BMR backup is 20GB, and all you want to do is recover a lost 1KB file, then you'd have to restore a 20GB BMR backup just to extract a 1KB file.

    Still, it does seem that technically the C: volume file backup of a server does not have to be protected by DPM if DPM protects the server's BMR backup.

    In my backup experience working with over 200 protected servers, only twice have I ever had to restore lost data from a server's C: drive. This translates into less than 1% of our file restores. The other 99% of restores are all from user and departmental data on the file servers' data volumes (non-C drives). Since there's no reason to back up file server data volumes with BMR, 99% or our restores can be done quickly through the DPM Administrator Console.

    So, if I can save potentially terabytes of backup space on the DPM servers by not protecting the file data on servers' C drives but instead just their BMR backups, and the only thing I give up is once or twice a year I'll have to spend 20 minutes to do the BMR-based file recovery proceedure outlined above instead of spending just 2 minutes doing it from a file backup for a server's C: drive, well, I can live with that.

    Keys to making this approach work is keeping just the operating system files and other necessary files on servers' C drives, and putting all other data on other volumes. The typical space used on the system volume for a Windows Server 2008 R2 installation is just 10-15GB, excluding the paging file.

    Another advantage to using only BMR backups for C: volumes is it could significantly reduce the number of protected data sources in DPM (whose supposed limit is 300) and reduce the size of the Logical Disk Manager database.

    I really hope that the Microsoft DPM folks comment on this issue since I hope we're not missing something with the BMR-only approach to protecting servers' C: drive files...

    Oh, and I never use DPM's default allocation for volume sizes. It almost always allocates too much storage space.

    -Taylorbox

    Friday, July 16, 2010 8:52 PM
  • Thanks for your input Taylorbox.

    I'm aware of the fact that you can technically recover even files/volumes from DPM's BMR backup. But (I'm not trying to be negative about DPM as I mostly like it otherwise) if this is ever be taken as enterprise class product, then I'd expect that it would allow me to do this procedure easily and not with cumbersome manual steps or keeping separate volume backup that takes additional space.

    I mean - recovery is the most important thing about backup products and I find DPM lacking a lot in this case.

    As for the 300-limit - I asked about this in another thread and those limits are "soft", ie. what has been tested that works.

    Friday, July 16, 2010 11:53 PM
  • Thanks for your valuable inputs. But technically that needs lots of changes to complete the scenario and the scenario is not that common. If possible we will consider it in future releases of DPM.
    Thanks, Praveen D [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, February 10, 2011 6:31 PM