none
How to calculate storage? RRS feed

  • Question

  • Hi,

    We are in the progress of configuring our DPM 2010 server, but I would need some help setting up the retention period for our data.

    We will protect the following data (on disk)

    SQL 2005/2008
    Exchange 2010
    SharePoint 2007
    Files
    Bare Metal

    What I would like to do is allocate a fixed size on the disk volume for each protection group. And then just tell DPM to keep as many days of data it can for that amount of space.

    One example could be if I allocate 2 TB for our Exchange backup and want to save the data for 20 days. What would happen if we reach 2 TB data after just 15 days?

    What I would like to do in this scenario is just let DPM delete the oldest Exchange data to make room for new data (regardless of how many days of retention I have set).

    Is this possible?

    Regards Erik

    Thursday, July 1, 2010 9:06 AM

Answers

  • Hi Krishna,

    I would appreciate if you could contact me on erik REMOVETHIS (at) droszcz.com and I will send you the Excel document :)

    Don't think I can attach it here on the forum.

    Regards Erik

     

    Monday, July 12, 2010 9:53 PM

All replies

  • Hi Eric,

    DPM will not delete the oldest Exchange data to make room for new data.  It will give you an error stating that it hasn't has enough disk space.  (Unless you use the automatic disk resizing option ofcourse).

    There are DPM sizing calculators but in the end, everything will be dependant on your churn.

    What you could do, is let it do its job, and change the protection group afterwards when you see that it is getting out of disk space.  However, this will remain dependant off the churn.  DPM only keeps the differences so....

    Anyway, the sizing calculators can be found here: (note they are still in draft...)

    http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=c136c66c-bd4a-4fb1-8088-f610cd02dc51

    Hope this makes it a bit clear

    cheers

    Mike Resseler


    Visit System Center User Group Belgium @ http://scug.be and http://scug.be/blogs/scdpm
    Thursday, July 1, 2010 9:44 AM
    Moderator
  • Hi Mike,

    Instead of preconfiguring the size of the volumes for each Exchange 2010 database on the DPM 2010 server I just set the retention period and automatically grow the volumes.

    Since this is a brand new Exchange 2010 server with no mailboxes (we will be migrating from Exchange 2007) DPM of course reserved a small amount of storage.

    Then I started of by moving just one mailbox to Exchange 2010.

    When I did that DPM gave me two messages

    Message 1:

    The following alert occurred at 7/2/2010 6:01:41 PM.
     
    Status: Active
    Data source type:
    Data source: MYDATABASE
    Computer: MYEXCHANGE2010 SERVER
    Description: Last 1 recovery points not created.

    DPM is out of disk space for the replica.


    Message 2:

    The following alert became inactive at 7/2/2010 8:02:17 PM.

    Status: Inactive
    Data source type:
    Data source: MYDATABASE
    Computer: MYEXCHANGE2010 SERVER
    Description: Last 1 recovery points not created.

    DPM is out of disk space for the replica.


    Is this OK (by design)? That DPM will trough this error when it is set to automatically grow the volumes. I guess message 2 means DPM managed to allocate more space when it ran the next sync?

    Regards Erik

     

    Saturday, July 3, 2010 10:11 AM
  • Hello Eric,

     

    You can look in the Application event log to see auto-grow activity, however, I would strongly encourage you to use the exchange storage calculator and size the volumes as close as possible to the required sizes (including future needs) to avoid autogrow activity.  Too much auto-grow on a DPM server protecting a lots of data source can lead to other problems, so please take the time up front to plan your storage needs for each exchange storage goup. 


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Saturday, July 3, 2010 5:42 PM
    Moderator
  • Mike,

    Thanks for the info!

    When looking at the storage calculator it says Total Storage on DPM/protected Exchange Node is 3 TB.

    But for LUN size it says about 5 TB.

    Just wonder, does that mean I need 5 TB of space on the DPM disk to protect my Exchange? Or will 3 TB be OK?

    // Erik

     

    Saturday, July 3, 2010 6:34 PM
  • Anyone of you guys know how I should work with the numbers?

    I also tried to send an email to dpmcalc@microsoft.com but I just got an auto reply letting me know the user is unknown.

    // Erik

     

    Tuesday, July 6, 2010 11:22 AM
  • Hi Erik,

     

    So you are referring to the LUN size under the DPM configuration tab ?  I'm not sure how that is calculated, but I think I would be looking at the "DPM Storage Requirements per Exchange server" DPM Primary requirements tab as that breaks down the replica and recovery point volume sizes that you need to use when creating the PG.

    I'll mail the author of the calculator and see if he can chime in to help clarify.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Tuesday, July 6, 2010 5:08 PM
    Moderator
  • Thanks a lot for dropping the author an email :)

    I have configured each replica volume and recovery point volume size according to the values on the DPM Primary Requirements tab.

    So I hope the value at Total Storage on DPM/protected Exchange Node is the one I can count on.

    But it would be really interesting to get more info on that LUN Size on the DPM Configuration tab.

    // Erik

     

    Tuesday, July 6, 2010 5:58 PM
  • Hi Erik,

    The DPM Primary Requirements tab shows you the size of the Recovery Point, Replica data.  The main ideas conveyed in this tab are:

    1. Number of DPM servers required and the sizing of the servers:  The data in section titled  DPM Storage Requirements per Exchange server is rolled up into the DPM Server Configuration section to provide the server hardware requirements.

    2. Backup SLAs:  One way of using the DPM Primary Requirements tab would be to go back and forth between the Input tab & DPM Primary Requirements tab till you arrive at the optimal combination of the Network bandwidth and Disk I/O required to meet the required backup SLA. 

    You would use the information in the DPM Configuration tab to determine the number of PGs and the number of Exchange DBs per PG.  Configuring DPM server in this manner will help you meet the SLAs in the DPM Primary Requirements tab.

    The LUN size shown in the DPM Configuration tab is the actual size that is required to store the Replica and the Recovery points for a PG for the specified Retention period.

    In summary:

    • You will use the Input tab and DPM Primary Requirements tab to determine the hardware needed to meet the required SLA.
    • You will use the configuratoin information in the  DPM Configuration tab to configure PGs in the DPM server to meet the SLA.

    Hope this helps.


    Regards, Krishna M [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights

    Thursday, July 8, 2010 1:33 PM
  • Hi Krishna,

    Thanks a lot for your feedback!

    I have managed to get the correct data on the Input and DPM Primary Requirements tabs.

    On the tab DPM Primary Requirements and the filed Total Storage on DPM/protected Exchange Node we got 2 TB and on the tab DPM Configuration tab and filed LUN Size 3426 GB.

    But then I know we need about 3.5 TB of free space on my DPM disks to protect the data :)

    Regards Erik

     

    Thursday, July 8, 2010 8:20 PM
  • Hi Erik,

    I would like to review the calc, you can either post it or let me know how I can get in touch with you and we can take this offline.


     

    Regards, Krishna M [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights

    Monday, July 12, 2010 1:21 PM
  • Hi Krishna,

    I would appreciate if you could contact me on erik REMOVETHIS (at) droszcz.com and I will send you the Excel document :)

    Don't think I can attach it here on the forum.

    Regards Erik

     

    Monday, July 12, 2010 9:53 PM
  • Hi Erik,

    Krishna will get in touch with you shortly. In the meantime I am closing this thread. Please feel free to reopen if your query does not get answered. 

     

    Thanks,

    Parag

    This posting is provided "AS IS" with no warranties, and confers no rights

    Tuesday, July 13, 2010 6:55 AM
    Moderator