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Allocated vs Utilized Space, Needing to Add More Clients RRS feed

  • Question

  • I have a 3TB Storage Pool that holds data for 2 protection groups.  One is a 600 GB group for SQL, the other group is for laptop clients on our network.  The Disk Utilization report shows that I have 2225 GB allocated to the laptop group and I am actually using 569 GB.  When setting this group up we allocated 10GB per client.  We were saving data for 10 days and were creating 3 recovery points per day.  I am running into a problem as allocated space is close to matching my storage pool size and I will not be able to add more clients. 

    I am considering reducing the amount of disk space allocated to each client to free up some room.  Would I first modify the disk allocation, delete the current replica, the rejoin the client to the group to make the new setting come into effect?  Or will changing the allocation while the clients are currently attached result in issues?

    Secondly, when I look at a client in the current configuration I see that for the replica volume (co-located) I have 100 GB allocated and the recovery point volume (co-located) is 21.56 GB.  These numbers are consistent across nearly 200 clients.  A couple of items bother me.  One, I do not have enough storage in the pool to allocate 121.56 GB per client for the 200 clients I currently am protecting, how is that being allocated?  Secondly, from what information are these numbers generated from?  The formulas I have seen show we should be allocating 15 GB per client for replica and 2.1 GB for recovery points based on our current settings.

     

    I am trying to get a better handle on what the total number of clients I will be able to protect with the 2.4 TB not being used by SQL in this storage pool with the settings I am considering (2 GB per client).  This is important as I need to protect more clients and leave some room for the SQL backups to grow if necessary.

     

    Ideas, thoughts, suggestions?

     

    Thanks

    Wednesday, September 7, 2011 10:25 PM

Answers

  • Deceks7,

    The default co-location factor of 10 allows scaling to 1000 clients per DPM server. To scale to 3000 clients / DPM server, the co-location factor needs to be increased to 30.  Customers with large scaled deployments have increased the value from 10 to 30.

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Data Protection Manager\Collocation\Client
    DSCollocationFactor:REG_DWORD:0xA (0x1E for 30)

    Space allocated by DPM for client protection based on GB / Client and with or without co-location enabled.  Number represent total space for both Replica and Recovery point volume.


    GB/client  Non-Colocated in GB  (10-Co-Located in GB)
    ======   =============     ===============
    1              2.91                             15.57
    2              4.37                             29.57
    3              5.77                             43.56
    4              7.17                             57.57
    5              8.56                             71.56
    10            15.57                          141.56
    20            29.57                          281.56

    If you need to rethink your storage or change GB/Client - then I strognly recommend that you stop protection and DELETE the replica, then reprotect the clients with the new DSCollocationFactor settings  and GB/Client allocation.    Keep in mind that the GB/Client is NOT a quota, and it's not a hard limit on amount of data that DPM can / will protect per client, it's just an estimation on overall storage needs on an average and if you allocate too little, you can either let DPM auto-grow (10GB or 25% of volume size which ever is larger) or manually grow the volume. 


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Monday, September 19, 2011 11:34 PM
    Moderator

All replies

  • When you first create the PG and you allocate space there is a check box where it says. Automatically grow size. This will allow DPM to grow the size of your recovery points if needed.

     

     

    What you can do if you have DPM 2010 is to right click on the PG and choose modify disk allocation and then shrink the recovery points. Notice that this option is only available in DPM 2010 and not 2007

     

    The numbers are generated according to the main total amount of data and 10% changes per day.

     

    Friday, September 16, 2011 1:57 PM
  • Deceks7,

    The default co-location factor of 10 allows scaling to 1000 clients per DPM server. To scale to 3000 clients / DPM server, the co-location factor needs to be increased to 30.  Customers with large scaled deployments have increased the value from 10 to 30.

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Data Protection Manager\Collocation\Client
    DSCollocationFactor:REG_DWORD:0xA (0x1E for 30)

    Space allocated by DPM for client protection based on GB / Client and with or without co-location enabled.  Number represent total space for both Replica and Recovery point volume.


    GB/client  Non-Colocated in GB  (10-Co-Located in GB)
    ======   =============     ===============
    1              2.91                             15.57
    2              4.37                             29.57
    3              5.77                             43.56
    4              7.17                             57.57
    5              8.56                             71.56
    10            15.57                          141.56
    20            29.57                          281.56

    If you need to rethink your storage or change GB/Client - then I strognly recommend that you stop protection and DELETE the replica, then reprotect the clients with the new DSCollocationFactor settings  and GB/Client allocation.    Keep in mind that the GB/Client is NOT a quota, and it's not a hard limit on amount of data that DPM can / will protect per client, it's just an estimation on overall storage needs on an average and if you allocate too little, you can either let DPM auto-grow (10GB or 25% of volume size which ever is larger) or manually grow the volume. 


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Monday, September 19, 2011 11:34 PM
    Moderator
  • I have made the co-location change to 30.  The modify disk allocation, however, will not let me go below 10 GB.  I have tried to move to 2 GB as 75% of my current targets use 2 GB or less.  When I click on OK after changing the Data per computer to 2 GB the number reverts to 10 GB.  I also must manually enter the number 2, as the arrows will not allow less than 10 GB.  I do have the Automatically grow the volumes marked.

     

    Is there a way to get this allocation to 2 GB or will I still be able to add numerous clients with the 10 GB default?

     

    Thanks

    Monday, October 3, 2011 5:38 PM
  • Hi,

    You cannot do this through the modify disk allocation screen. You will need to stop protection and delete the replica volume - then reprotect the clients if you want to take advantage of the new co-location setting of 30 and reduce the per client disk usage setting. 

    Please be aware of this behavior when removing co-located data sources from protection:

    http://blogs.technet.com/b/dpm/archive/2010/11/03/protect-unprotect-protect-unprotect-understanding-how-dpm-2010-retention-works.aspx?CommentPosted=true#commentmessage

     


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Monday, October 3, 2011 7:08 PM
    Moderator
  • I have of yet been unable to modify the Disk Allocation to any number but 10GB.  I did change the co-location setting to 30 as described above.  Any time I try to re-size below 10GB the setting will not take.  I am using 680 GB of space and have 2.9 TB allocated.  I have 326 computers showing to be protected and cannot add any more.
    Tuesday, November 1, 2011 4:46 PM
  • From the original post, you showed 2225 GB allocated to the laptop group and actually only using 569 GB.   It doesn't sound like you removed the clients from protection and deleted replica then reprotected with smaller value for gb/client.    That's the only supported method of reclaimimg the wasted space for the replica volumes.


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Wednesday, November 2, 2011 12:05 AM
    Moderator
  • I am in the process of removing and adding them back.  On the new clients, however, I am still unable to select an allocation smaller than 10GB per client.  Before I made the change I would run out of "space" at about 220 clients.  I am up to over 300 total now, but the data per computer under modify disk allocation cannot be reduced to less than 10 GB, and that is true on the new clients I have added. Does this Data per computer set a limit to the number of clients you can add given a finite pool?

     

    Thanks

    Wednesday, November 2, 2011 6:15 PM
  • Hi,

    The original protection group you created with the 10GB / Client allocation cannot be reduced below 10GB by modifying the PG.  The NEW protection group you create will allow you to use a smaller number, as little as 1GB / client.  To free up the disk space consumed by the original PG will require you to stop protection and delete the replica.  Yes, you will loose all your backups, but that is the only supported way to reclaim the disk space that was over allocated. 

    If I read your numbers correctly, you are protecting 326 clients and DPM is using 650GB on the replics, that averages out to be 2GB / client.  So when you make the NEW protection group, specify 2GB for the Data per computer option.


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, November 3, 2011 12:03 AM
    Moderator
  • When you say stop protection and delete the replica; does this need to be done en masse or can I delete a % and then create the new PG?  After creating the new PG I could add clients and continue the process of removing and then adding back to the new PG as disk space cleared?  I am trying to minimize the amount of time my laptops are exposed without a backup.

     

    Thanks again for your guidance.

    Thursday, November 3, 2011 7:00 PM
  • HI,

    You can do them in groups of machines that are co-located and share the same replica.  That will ensure that the disk space is freed up so you can reprotect them in a new PG since your tight on space.

    Run these DPM power shell commands to Get datasource path for co-located data sources.
    Where protectiongroupname = the protection group you want to get information for.


    $pg = get-protectiongroup (&hostname) | ? { $_.friendlyname -eq 'protectiongroupname'}
    get-datasource $pg  | sort-object -property replicapath | ft replicapath, name, diskallocation -AutoSize

     

    The output will show which client is located on which replica volume.  ALL Clients on a given replica must be removed from protection before the replica and recovery point volume will be deleted.

    There are three columns in the output, the replica volume GUID, the name of the data source, and the size of the co-located volume that will be freed.    Remove from protection all clients that share the same volume GUID. 


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, November 3, 2011 10:35 PM
    Moderator