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DPM Tape Backup Terminology. RRS feed

  • Question

  • I am struggling to understand some points on DPM Tape backups functionality. Before I made changes to DPM tape infra... I need to understand below points. please someone clear these.... Thanks in advance.

    1) Is Recovery Point (on Tape) expiry and Tape expiry are different? If Yes then from where I can set tape expiry? What will happen if recovery point is expired and tape not expired and vise-versa?

    2) Why does DPM allows recovery points to recovered even when Tape expire. I think RETENTION means is nothing if it allows even after tape expiration. Isn't it breaching RETENTION Policy?

    3) a) I don't want tape to be offsite ready until its get fully written. Where I can find this option?

        b) I want tape to be offsite ready after one month, no matter it fulls or half used. Where I can find this option?

    4) My tapes currently getting offsite ready frequently, where I can find offsite policy which is set to them?

    5) When I create co-located protection group set under optimization, from 4 groups it pick ups random name for tape label. from where I can set custom tape level?

    Wednesday, March 26, 2014 4:06 PM

Answers

  • Hi,

    Q1) Is Recovery Point (on Tape) expiry and Tape expiry are different? If Yes then from where I can set tape expiry? What will happen if recovery point is expired and tape not expired and vise-versa?

    A1)  They are different, if a tape is used for multiple backup sessions (or different retention goals are on the same tape) then individual tape sets (recovery points) can expire at different times.  In that case, the tape will contain expired recovery points, but may also contain non-expired recovery points.  In that case, the tape will not be marked as expired until ALL recovery points are expired on the tape.  In summary, the tape will show expired after ALL recovery points written to that tape have expired. 


    Q2) Why does DPM allows recovery points to recovered even when Tape expire. I think RETENTION means is nothing if it allows even after tape expiration. Isn't it breaching RETENTION Policy?

    A2) If you try to recover a recovery point from an expired tape, you should get a popup error:

        Problem: DPM could not recover the requested data.
       The selected recovery point is no longer available for recovery.


    Q3-a) I don't want tape to be offsite ready until its get fully written. Where I can find this option?

    A3-a) Adjust the "Write Period"  in the properties of the tape optimization co-location set so the tape can be available long enough to fill it.


    Q3-b) I want tape to be offsite ready after one month, no matter it fulls or half used. Where I can find this option?

    A3-B) Adjust the "Write Period" to 30 days in the properties of the tape optimization co-location set
    .

    Q4) My tapes currently getting offsite ready frequently, where I can find offsite policy which is set to them?

    A4) tapes will be marked offsite ready for one of the following reasons.

    a) The tape is full.
    b) The "write period" in the properties of the tape optimization co-location set has been reached.
    c) A recovery point already written to tape has expired.

    Q5) When I create co-located protection group set under optimization, from 4 groups it pick ups random name for tape label. from where I can set custom tape level?
    A5) You can manually change the tape label by viewing each PG's "Custom Recovery Goal" page for tape backups. Click the default tape label and change it to be your custom label.
        Since tapes are allocated as needed when a new tape backup is perfromed, the tape label comes from the PG whose first dataset it written to that tape.  So if you want uniform tape labels, rename them to be the same in all PG's that are co-located together. 


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.



    Wednesday, March 26, 2014 9:32 PM
    Moderator
  • Hi,

    If you attempt to restore a recovery point from an "expired" tape you will get that error message that stated earlier.  You can mark the tape as free and then unmark it free which will then show Imported - at that time it is no longer an "expired" tape and you can recatalog it to restore data from it. 

    1) Right-click the Expired tape and select "Mark tape as free" - the label will change to "Free (contains data)
    2) Right-click the free tape and select "Unmark tape as free" - the label will show as (Imported) <the origninal tape label>.
    3) Right-click the Imported tape and select "Recatalog imported tape" Once cataloged, the tape contents should show up under the recovery tab under the EXTERNAL DPM TAPES, and you should be able to browse the contents and restore from there.

    The restore options available will be limited to restoring to a network share or disk of any server that has an agent installed.  You cannot restore back to original location.

    No mention on the frequency of the tape backups, but the Expiration tolerance is the maximum length of time for which an expired recovery point can remain on a tape until the tape is marked as expired.  This simply controls if the next backup that will be written to tape will be on the already allocated tape, or if a new tape is required.  Basically, we don't want to keep writing to a tape even if the write period is long if that new recovery point will prevent the tape from expiring within a certain time period of the first data set expiring.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.

    • Marked as answer by V Jay Rana Friday, May 30, 2014 11:50 AM
    Friday, March 28, 2014 4:31 PM
    Moderator
  • Get it now, thanks :)

    • Marked as answer by V Jay Rana Friday, May 30, 2014 11:49 AM
    Friday, March 28, 2014 4:39 PM
  • Hi,

    DPM always writes a full backup from the last successful disk based recovery point.  In your example above, ~42GB will be written to tape for that data source.

    You can created a Custom filter under Management - Jobs and just select the tape backup job type for the time window that spans your tape backup jobs.  You can then see how data much was written to tape for each data source and the tape label / barcode. 


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.

    • Marked as answer by V Jay Rana Friday, May 30, 2014 11:49 AM
    Monday, April 14, 2014 2:28 PM
    Moderator

All replies

  • Hi,

    Q1) Is Recovery Point (on Tape) expiry and Tape expiry are different? If Yes then from where I can set tape expiry? What will happen if recovery point is expired and tape not expired and vise-versa?

    A1)  They are different, if a tape is used for multiple backup sessions (or different retention goals are on the same tape) then individual tape sets (recovery points) can expire at different times.  In that case, the tape will contain expired recovery points, but may also contain non-expired recovery points.  In that case, the tape will not be marked as expired until ALL recovery points are expired on the tape.  In summary, the tape will show expired after ALL recovery points written to that tape have expired. 


    Q2) Why does DPM allows recovery points to recovered even when Tape expire. I think RETENTION means is nothing if it allows even after tape expiration. Isn't it breaching RETENTION Policy?

    A2) If you try to recover a recovery point from an expired tape, you should get a popup error:

        Problem: DPM could not recover the requested data.
       The selected recovery point is no longer available for recovery.


    Q3-a) I don't want tape to be offsite ready until its get fully written. Where I can find this option?

    A3-a) Adjust the "Write Period"  in the properties of the tape optimization co-location set so the tape can be available long enough to fill it.


    Q3-b) I want tape to be offsite ready after one month, no matter it fulls or half used. Where I can find this option?

    A3-B) Adjust the "Write Period" to 30 days in the properties of the tape optimization co-location set
    .

    Q4) My tapes currently getting offsite ready frequently, where I can find offsite policy which is set to them?

    A4) tapes will be marked offsite ready for one of the following reasons.

    a) The tape is full.
    b) The "write period" in the properties of the tape optimization co-location set has been reached.
    c) A recovery point already written to tape has expired.

    Q5) When I create co-located protection group set under optimization, from 4 groups it pick ups random name for tape label. from where I can set custom tape level?
    A5) You can manually change the tape label by viewing each PG's "Custom Recovery Goal" page for tape backups. Click the default tape label and change it to be your custom label.
        Since tapes are allocated as needed when a new tape backup is perfromed, the tape label comes from the PG whose first dataset it written to that tape.  So if you want uniform tape labels, rename them to be the same in all PG's that are co-located together. 


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.



    Wednesday, March 26, 2014 9:32 PM
    Moderator
  • HI Mike,

    Thanks for your reply and making my doubts clear. But here I am still confused in my question no 2.

    2) Why does DPM allows recovery points to recovered even when Tape expire. I think RETENTION means is nothing if it allows even after tape expiration. Isn't it breaching RETENTION Policy?

    Now I have set tape backups expiration to 5 years (260 weeks). So after 5 years, will I be not able to restore that data in anyway? I was reading about this and found this official link of Microsoft Recovering Data from Expired Tapes like free and recatalog tapes. then it is different method? Management team asked me to set tape policy in such a way so that after 5 years ... We should be able to recover that data. Is it possible to do this..! with certificate on DPM or encryption etc? please suggest.

    2) I understood above points, I set tape retention to 5 years, I set offsite time to 90 days so 3 months are enough to fill and use full tape. Should I also set 'Expiry Tolerance' to 5 years?


    Friday, March 28, 2014 12:39 PM
  • Hi,

    If you attempt to restore a recovery point from an "expired" tape you will get that error message that stated earlier.  You can mark the tape as free and then unmark it free which will then show Imported - at that time it is no longer an "expired" tape and you can recatalog it to restore data from it. 

    1) Right-click the Expired tape and select "Mark tape as free" - the label will change to "Free (contains data)
    2) Right-click the free tape and select "Unmark tape as free" - the label will show as (Imported) <the origninal tape label>.
    3) Right-click the Imported tape and select "Recatalog imported tape" Once cataloged, the tape contents should show up under the recovery tab under the EXTERNAL DPM TAPES, and you should be able to browse the contents and restore from there.

    The restore options available will be limited to restoring to a network share or disk of any server that has an agent installed.  You cannot restore back to original location.

    No mention on the frequency of the tape backups, but the Expiration tolerance is the maximum length of time for which an expired recovery point can remain on a tape until the tape is marked as expired.  This simply controls if the next backup that will be written to tape will be on the already allocated tape, or if a new tape is required.  Basically, we don't want to keep writing to a tape even if the write period is long if that new recovery point will prevent the tape from expiring within a certain time period of the first data set expiring.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.

    • Marked as answer by V Jay Rana Friday, May 30, 2014 11:50 AM
    Friday, March 28, 2014 4:31 PM
    Moderator
  • Get it now, thanks :)

    • Marked as answer by V Jay Rana Friday, May 30, 2014 11:49 AM
    Friday, March 28, 2014 4:39 PM
  • Hi Mike, 

    I have one more question. How data is written to tape for an individual datasource or protection group? I have 6 Protection groups co-located to a single tape with optimization. Now about 900GB data written in a week, but I am unable to find which datasource is using much among this 900 GB. I think if I understand how data is written to tapes with replica+recovery points, then I will find big one datasource and exclude it. Here is an example, can you please explain with its, it will be more usefull.

    For example, I have protection group alocated space 500GB

    1 datasousre in it Replica volume allocated = 50 GB, Used= 42 GB

                                   Recovery Point Volume = 35 GB, Used = 28GB (7 Recovery Points)

    How much data will written for this datasource weeklty? and with which combination, I mean with combination like (replica+last express backup?) or (Replica+all incrementals sequentially?)

    Monday, April 14, 2014 2:04 PM
  • Hi,

    DPM always writes a full backup from the last successful disk based recovery point.  In your example above, ~42GB will be written to tape for that data source.

    You can created a Custom filter under Management - Jobs and just select the tape backup job type for the time window that spans your tape backup jobs.  You can then see how data much was written to tape for each data source and the tape label / barcode. 


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.

    • Marked as answer by V Jay Rana Friday, May 30, 2014 11:49 AM
    Monday, April 14, 2014 2:28 PM
    Moderator