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DPM2010 - Best practice for backing up direct to tape RRS feed

  • Question

  • We're looking at implementing DPM2010 in-house to back up our various Exchange and SQL servers. Now, because of current budgetary constraints we don't have lots of disk space to allocate to DPM. Until we do, I was thinking of using DPM to backup directly to tape. We have about 3TB of server data to protect and I don't mind swapping tapes. Assuming we have an incremental daily data amount of 15% and let's say I use LTO 2/3 (200/400GB), do you think this is a workable plan?
    Thursday, July 1, 2010 11:22 AM

Answers

  • Hello Andy,

     

    DPM does not support short term "incremental backup" to tape for application data (Exchange, SQL, Hyper-V, Sharepoint) - all backups are full backups.  Only File data (volumes / shares) can be backed up incrementally.  So, of the 3TB of data you need to protect, how much is application data and how much is file data ?  How often do you plan on taking backups ?  The answers to those questions will determine if it's feasible or not.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, July 1, 2010 3:30 PM
    Moderator
  • Hi,

     

    OK, if you only have a standalone tape drive, things are a little different, and may be hard to predict when a new tape will be required for backup jobs.  I would invest in a tape library - or possibly add another standalone tape drive so you can isolate the application data from the file data by placing them in seperate protection groups and assiging each PG a different tape drive to use.

     

    For standalone tape drives, for each protection group all SHORT TERM backups are appended on a single tape , and for each protection group all LONG TERM backups are appended to a single tape (different from the short term tapes). As tapes fill up,
    DPM will raise an alert to add a new free tape.

    DPM will prompt for another free tape to continue backup. It will wait for 1 hour by default before failing the job. This prompting timeout can be configured by the registry entry "PromptingTimeOut" under "HKLM\Software\Microsoft\Microsoft Data
    Protection Manager\1.0\Prompting"

    PromptingTimeOut:REG_Dword:43200000 (dec) = 12hrs

    =-=-=Value is in milliseconds=-=-=
    3600000 = 1 hour
    43200000 = 12 hours
    86400000 = 24 hours
    129600000 = 36 hours
    172800000 = 48 hours

    SHORT TERM TAPE PROTECTION
    ==============================
    A) Short-term tape "full" option - backup jobs will require a FREE tape for each scheduled job.
    B) Short-term tape "full and incremental" option - the FULL backup will require a FREE tape for each scheduled job and the Incremental backup for all data sources will be appended to different tape.

    As tapes fill up, new free tapes will be allocated.

    When the next FULL backup occurs, that will require another FREE tape, and subsequent Incremental will be appended to another FREE tape.

    Example: If Full is scheduled weekly and incremental daily- then the first full will go to a new free tape and all subsequent incrementals for 6 days will be appended to different new free tape.



    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, July 2, 2010 6:39 PM
    Moderator
  • Hi

    Yes, that sounds right, what I would do is start off with the hardware you have and try to make sence of the tape requirements and the amount of time it takes to do the backups to a single standalone tape drive.  If changing tapes becomes a challenge, or the backups cannot get finished in the desired amount of time, you can then think about purchasing a tape library with multiple drives, or just adding additional standalone drive(s) - whatever fits your budget.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    • Marked as answer by AndyChips Tuesday, July 6, 2010 9:32 AM
    Monday, July 5, 2010 3:59 PM
    Moderator

All replies

  • Hello Andy,

     

    DPM does not support short term "incremental backup" to tape for application data (Exchange, SQL, Hyper-V, Sharepoint) - all backups are full backups.  Only File data (volumes / shares) can be backed up incrementally.  So, of the 3TB of data you need to protect, how much is application data and how much is file data ?  How often do you plan on taking backups ?  The answers to those questions will determine if it's feasible or not.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, July 1, 2010 3:30 PM
    Moderator
  • Mike:

    Is there a way to keep x number of days on disk and shoot only incrementals to tape for file data? 

    thanks

    Homer

    Thursday, July 1, 2010 7:48 PM
  • Hi,

     

    Unfortunatly No - long term backup to tape will always be full backups regardless if short term backup is disk or tape based.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, July 1, 2010 8:20 PM
    Moderator
  • Mike, your first two sentences are one of the most useful nuggets of info I've come across during my extensive research, so thanks for that.

    To answer your questions:

    1. Exchange, Sharepoint and SQL will make up about 100GB.
    2. The rest will be fairly static and at a rough guess I'd reckon on a maximum of 80GB of daily changes. This will mainly be Office documents, developer source & binaries, web site, etc.
    3. We plan on taking nightly backups and hope to get away with one tape a day. If that's not possible then it's not the end of the world.

    So I'm guessing that Exchange, Sharepoint and SQL will be backed up in full each night, with the remaining file data backing up incrementally?

    Also, I've seen that you need one tape per protection group. Is this a show-stopper if we don't have a library or get fed up with repeated tape changes?

    Many thanks,
    Andy.

    Friday, July 2, 2010 8:33 AM
  • Hi,

     

    OK, if you only have a standalone tape drive, things are a little different, and may be hard to predict when a new tape will be required for backup jobs.  I would invest in a tape library - or possibly add another standalone tape drive so you can isolate the application data from the file data by placing them in seperate protection groups and assiging each PG a different tape drive to use.

     

    For standalone tape drives, for each protection group all SHORT TERM backups are appended on a single tape , and for each protection group all LONG TERM backups are appended to a single tape (different from the short term tapes). As tapes fill up,
    DPM will raise an alert to add a new free tape.

    DPM will prompt for another free tape to continue backup. It will wait for 1 hour by default before failing the job. This prompting timeout can be configured by the registry entry "PromptingTimeOut" under "HKLM\Software\Microsoft\Microsoft Data
    Protection Manager\1.0\Prompting"

    PromptingTimeOut:REG_Dword:43200000 (dec) = 12hrs

    =-=-=Value is in milliseconds=-=-=
    3600000 = 1 hour
    43200000 = 12 hours
    86400000 = 24 hours
    129600000 = 36 hours
    172800000 = 48 hours

    SHORT TERM TAPE PROTECTION
    ==============================
    A) Short-term tape "full" option - backup jobs will require a FREE tape for each scheduled job.
    B) Short-term tape "full and incremental" option - the FULL backup will require a FREE tape for each scheduled job and the Incremental backup for all data sources will be appended to different tape.

    As tapes fill up, new free tapes will be allocated.

    When the next FULL backup occurs, that will require another FREE tape, and subsequent Incremental will be appended to another FREE tape.

    Example: If Full is scheduled weekly and incremental daily- then the first full will go to a new free tape and all subsequent incrementals for 6 days will be appended to different new free tape.



    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, July 2, 2010 6:39 PM
    Moderator
  • Mike, your reply is extremely useful. Many thanks.

    So, I'm guessing that I really need to get a library. If not, your last example scenario is possibly closest to our predicted schedule, so I'm assuming that if the daily incrementals mostly fit on one tape per week, then the weekend Fulls will fit on one or two more (per week) - which we can change at leisure during the working day. Does that sound about right as regards tape usage?

    Budgets are tight, but the more I think about this, the more I think we need a library.

    Regards, Andy.

    Monday, July 5, 2010 3:13 PM
  • Hi

    Yes, that sounds right, what I would do is start off with the hardware you have and try to make sence of the tape requirements and the amount of time it takes to do the backups to a single standalone tape drive.  If changing tapes becomes a challenge, or the backups cannot get finished in the desired amount of time, you can then think about purchasing a tape library with multiple drives, or just adding additional standalone drive(s) - whatever fits your budget.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    • Marked as answer by AndyChips Tuesday, July 6, 2010 9:32 AM
    Monday, July 5, 2010 3:59 PM
    Moderator
  • Oh good, I finally think I'm starting to grasp some of the concepts behind this. The problem is, the place I worked before had a huge SAN and LTO library dedicated to DPM. Things were so simple there because the library took care of all the fiddly tape rotations. It's different here where I have no money to spend and have to think about paring the kit to the bone whilst keeping the tape rotations humanly possible.
    Mike, you've been a star. Thanks for all your help.

    Andy.

    Tuesday, July 6, 2010 8:16 AM
  • Anybody knows how to modify the "Prompting" behaviour on DPM 2010 ?
    Thursday, July 8, 2010 10:30 AM
  • Hello I've been having the same concern and through some tests it seems incremental to tape is possible:

    https://social.technet.microsoft.com/Forums/en-US/fa554d2b-4f23-4ff6-813a-e5162c98a86a/dpm-2016-with-dtodtot?forum=dpmtapebackuprecovery

    Your thoughts?


    Regards Peter

    Monday, August 13, 2018 6:32 AM