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DPM 2010 - Tape Backup and Recovery FAQ RRS feed

  • Question

  • Hi,  I have several questions about recovering data from a tape.

     

    1. Can I recover data from a tape backup created by DPM without a DPM Server?

     

    2. Say I have a 2 year old tape backup and the DPM Server had to be completely rebuilt from scratch last week.  Can I recover all the data from that tape?

     

    3. Can i recover data from a tape that was created from an earlier version of DPM?  

     

    4. Will the data on a tape backup I create with DPM 2010 be capable of being restored in by using future versions of DPM?  If so, is there any log files that need to be kept or other requirements to do this?

     

    I realize that this is a handful of questions, but I decided that they are closely related enough so I grouped them together.  I hope you don't mind.

     

    Thanks a bunch!

    Friday, July 2, 2010 10:40 PM

Answers

  • Hello,

    1. Can I recover data from a tape backup created by DPM without a DPM Server?

       ANSWER: DPM writes to the tape using Microsoft Tape Format (MTF) - however it it not compatible with NTbackup, so the short answer is yes, you will need to use DPM to restore from the tapes.   

    2. Say I have a 2 year old tape backup and the DPM Server had to be completely rebuilt from scratch last week.  Can I recover all the data from that tape?

      ANSWER: Yes, To ensure you can restore back to the original source servers, you will need to create the new DPM server using the same name, then restore the DPM DB from the original DPM server. Make sure part of your disaster recovery plan includes backing up the DPMDB on a regular basis.   If you were to some how loose the original DPM server and didn't have a backup of the DB, then you can import the tapes created on the original DPM server - then re-catalog and restore data to a network location as flat files.  This can be any server that has a protection agent installed

    3. Can i recover data from a tape that was created from an earlier version of DPM?  

     ANSWER: Yes, if you upgrade from DPM2007 to DPM2010, then tape remain restorable just like before the upgrade.  If you move tapes between different DPM servers (same or different version) you just need to import the tapes - then re-catalog them, but the restriction will be all restores will be as flat files, you cannot restore back to original location natively, so this means application data like exchange and SQL DB's would be restored as flat files, they you would need to import or attach the DB's manually.

    4. Will the data on a tape backup I create with DPM 2010 be capable of being restored in by using future versions of DPM?  If so, is there any log files that need to be kept or other requirements to do this?

      ANSWER: I cannot provide a roadmap of future DPM versions, but historically, we do maintain backwards compatibility.

     


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, July 2, 2010 11:07 PM
    Moderator
  •  

    Hi,

    1. How long does DPM keep the catalog by default?

    ANSWER: By Default, tape catalogs are maintained for the duration of the retention period for the protection group. This is configurable as mentioned previously. 

    2. What information is held in this catalog?

    ANSWER: When you attempt to restore data from under the recovery tab, you need to expand out the protected server and data source data before you can recover an item.  This detail is contained in SQL DB and in the case of tape backups, maintained as per the tape catalog retension settings.  So if you choose to prune the tape catalog after 4 weeks, then try to restore from tape on the 5th week, you will be prompted to re-catalog the tape before you can see the items that are restorable and be able to do the restore.  So the short answer is the tape catalog consists of file and directory listings of all the data that is on the tape.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Monday, July 5, 2010 4:40 PM
    Moderator

All replies

  • Hello,

    1. Can I recover data from a tape backup created by DPM without a DPM Server?

       ANSWER: DPM writes to the tape using Microsoft Tape Format (MTF) - however it it not compatible with NTbackup, so the short answer is yes, you will need to use DPM to restore from the tapes.   

    2. Say I have a 2 year old tape backup and the DPM Server had to be completely rebuilt from scratch last week.  Can I recover all the data from that tape?

      ANSWER: Yes, To ensure you can restore back to the original source servers, you will need to create the new DPM server using the same name, then restore the DPM DB from the original DPM server. Make sure part of your disaster recovery plan includes backing up the DPMDB on a regular basis.   If you were to some how loose the original DPM server and didn't have a backup of the DB, then you can import the tapes created on the original DPM server - then re-catalog and restore data to a network location as flat files.  This can be any server that has a protection agent installed

    3. Can i recover data from a tape that was created from an earlier version of DPM?  

     ANSWER: Yes, if you upgrade from DPM2007 to DPM2010, then tape remain restorable just like before the upgrade.  If you move tapes between different DPM servers (same or different version) you just need to import the tapes - then re-catalog them, but the restriction will be all restores will be as flat files, you cannot restore back to original location natively, so this means application data like exchange and SQL DB's would be restored as flat files, they you would need to import or attach the DB's manually.

    4. Will the data on a tape backup I create with DPM 2010 be capable of being restored in by using future versions of DPM?  If so, is there any log files that need to be kept or other requirements to do this?

      ANSWER: I cannot provide a roadmap of future DPM versions, but historically, we do maintain backwards compatibility.

     


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, July 2, 2010 11:07 PM
    Moderator
  • Great answers, thanks Mike.  I have one several follow up questions.

    1. I remember seeing somewhere that DPM prunes the database on some sort of schedule.  Is this true?  How will this affect archived tapes?

    2. What is the best way to backup the DPM Database?  (I am unfamiliar with SQL Server)

    • Edited by Caleb44 Sunday, July 4, 2010 1:12 AM mistyped a word
    Sunday, July 4, 2010 1:12 AM
  •  

    1. I remember seeing somewhere that DPM prunes the database on some sort of schedule.  Is this true?  How will this affect archived tapes?

    ANSWER: For tape based backups, we keep a catalog in the SQL DB for each backup.  You can control when the catalog gets trimmed to avoid SQL DB growth.  To change the settings, while under the protection tab, click on the link on the right pane  to  configure tape catalog.

    2. What is the best way to backup the DPM Database?  (I am unfamiliar with SQL Server)

    ANSWER: You can configure DPM 2010 to backup it's own database to disk, tape, or both, or you can run dpmbnackup -db from command prompt to back it up to the c:\program files\Microsoft dpm\dpm\volumes\shadowcopy\database backup folder.  You can also use a secondary DPM server to back it up.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Sunday, July 4, 2010 4:27 PM
    Moderator
  • Again, great answers.  And again, several more follow up questions.  :)

     

    1. How long does DPM keep the catalog by default?

     

    2. What information is held in this catalog?

     

     

    Sunday, July 4, 2010 6:53 PM
  •  

    Hi,

    1. How long does DPM keep the catalog by default?

    ANSWER: By Default, tape catalogs are maintained for the duration of the retention period for the protection group. This is configurable as mentioned previously. 

    2. What information is held in this catalog?

    ANSWER: When you attempt to restore data from under the recovery tab, you need to expand out the protected server and data source data before you can recover an item.  This detail is contained in SQL DB and in the case of tape backups, maintained as per the tape catalog retension settings.  So if you choose to prune the tape catalog after 4 weeks, then try to restore from tape on the 5th week, you will be prompted to re-catalog the tape before you can see the items that are restorable and be able to do the restore.  So the short answer is the tape catalog consists of file and directory listings of all the data that is on the tape.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Monday, July 5, 2010 4:40 PM
    Moderator
  • That is very helpful.  Thanks Again!
    Tuesday, July 6, 2010 2:31 PM
  • this post has been really helpful mike was wondering if you could answer a few more questions:)

    1. say i have a folder that is 800 GB that needs to backed up to tape everyday as well as to disk. my question is how do i know the exact amount of space required for a tape if selcted as the long term protection??  is it 800GB? or more??

    2. if written with compressed option how much will be required on the tape??if no exact science any way i can verify it?? I need to know this to buy adequate number of tapes and not exceed more than required.

    I've tested the tape drive backup speed and it does about 150GB per hour since I have only 1 tape drive and many proection groups with huge amounts of data i need to verify the correct space so i can allocate time accordingly

    Final question

    3. from what i understand i could restore any long term tape backup as flat files as long as i have a dpm server somewhere?? if this is the case if somebody stole my tapes he would be able to recover my data right?? and using encrypt i will be able to pevent this right?? say its a total site disaster and i had only one dpm server server which backed up to tape using encryption, if my domain and all are backed up using this dpm server how can i recover my servers??


    Tuesday, July 5, 2011 6:38 PM
  • Hi

    Q1. say i have a folder that is 800 GB that needs to backed up to tape everyday as well as to disk. my question is how do i know the exact amount of space required for a tape if selcted as the long term protection??  is it 800GB? or more??

    A1.  Since you are doing Disk-Disk-Tape backup, the amount of data that will be backed up to tape will be equal to the amount of used space on the replica volume.   That is viewable in the details of the protected data source.

    Q2. if written with compressed option how much will be required on the tape??if no exact science any way i can verify it?? I need to know this to buy adequate number of tapes and not exceed more than required.

    A2.  Typical tape compression ratios are 2/1 - but that really all depends on the type of data being protected.  .VHD, .Jpeg, and other already compressed file will typically not compress further.

    I've tested the tape drive backup speed and it does about 150GB per hour since I have only 1 tape drive and many proection groups with huge amounts of data i need to verify the correct space so i can allocate time accordingly

    Final question

    Q3. from what i understand i could restore any long term tape backup as flat files as long as i have a dpm server somewhere?? if this is the case if somebody stole my tapes he would be able to recover my data right?? and using encrypt i will be able to pevent this right?? say its a total site disaster and i had only one dpm server server which backed up to tape using encryption, if my domain and all are backed up using this dpm server how can i recover my servers??

    A3. Correct - using tape encryption will secure your tape data.  You need to export the encryption certificate (including the private key) and store it offsite so you can import it back into the newly rebuilt DPM server.  See http://technet.microsoft.com/en-us/library/bb808937.aspx

      

     


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    • Proposed as answer by DIFFMEISTER Wednesday, July 6, 2011 5:29 PM
    Tuesday, July 5, 2011 11:32 PM
    Moderator
  • thanks mike, like your style of answering precise and to the point, amazing.
    Wednesday, July 6, 2011 5:30 PM
  • Mike one more question:),

    Say this is My Long Term Tape Schedule, and that I have Tape that can hold 800GB Since the space fits in 800 GB can I enable co location on Tape and use 2 tapes instead of 2 tapes for each protection group??

    If I use without co location i would have to use 2 Tapes per protection group to fit the retention period which would end up with 8 Tapes. What I want to confirm is can i enable collocation and put all these protection groups in one tape so that with the retention period i'm only going to need 2 tapes??

     

    Protection Group

    Approximate Space Required on Tape

    Required Time Approximately

    Backup Frequency

    Retetion Period

    Time

    Group 1

    18.33 GB

    12 mins

    Monthly ( Every First Sunday)

    1 Month

    Sunday 9.00a.m

    Group 2

    61.66 GB

    40 mins

    Monthly (Every First Sunday)

    1 Month

    Sunday 10.00a.m

    Group 3

    23.00 GB

    15 mins

    Monthly (Every First Sunday)

    1 Month

    Sunday 12.00p.m-4.00p.m

    Group 4

    429.00GB

    3.30 Hours

    Monthly (Every First Sunday)

    1 Month

    Sunday 5.00p.m -10.00p.m

    • Edited by DIFFMEISTER Thursday, July 7, 2011 8:50 AM Table out
    Thursday, July 7, 2011 8:35 AM
  • from my understanding the above stated question has been answered in another thread and the answer to the question is yes.

    this answer can be found by visiting the following link

    http://social.technet.microsoft.com/Forums/en-US/dpmtapebackuprecovery/thread/68586c0e-7203-47c8-85a9-85a9898d4b8d

     

    Sunday, July 10, 2011 7:45 PM