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Storage Pool Disk Size Best Practise ?? RRS feed

  • Question

  • One of my DPM 2010 servers has 2 x 3TB LUNS assigned from SAN used as Disk Storage. I have attached an HP MDS600 unit with 30TB capacity and I will run the migrate script to move the data.

    My question is in setting up the new storage -

    Is it better to make this one large RAID5 or RAID6 Volume using nearly 30TB ?

    or

    Make smaller 5-6TB drives and assign them as needed ?

     

     

     

     

     

    Friday, August 20, 2010 5:41 AM

Answers

  • Hi,

    So here are the current restrictions, so as long as you don’t break any of them, then make the storage as you please.

    Master boot record (MBR) disks have a 2TB Physical disk limit.
    Although Windows support > 17 TB GUID partition table (GPT) disk – DPM dev group recommends Maximum of 17 TB for GUID partition table (GPT) dynamic disks.

    NTFS only support 16TB Volume sizes using default cluster sizes, so if you need to protect any (co-located) data sources that need a larger volume, you will need to format the replica volume manually to use a larger cluster size.
    Windows VDS Service only support a maximum of 32 member spanned volumes, so to avoid bumping into that limitation (hard to do, but in theory it could bite you)  - I would not add more than 32 disks to the DPM storage pool.

    So, to sum this up,

    1) Make your LUNS any size you want not to exceed 17TB – best practice would be to convert them all to GPT so you can grow them past the 2TB size.
    2) Do not exceed the  80 TB per DPM server.  http://technet.microsoft.com/en-us/library/ff399280.aspx
    3) Do not add more the 32 disks to the DPM storage pool.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, August 20, 2010 3:22 PM
    Moderator

All replies

  • Hi,

    So here are the current restrictions, so as long as you don’t break any of them, then make the storage as you please.

    Master boot record (MBR) disks have a 2TB Physical disk limit.
    Although Windows support > 17 TB GUID partition table (GPT) disk – DPM dev group recommends Maximum of 17 TB for GUID partition table (GPT) dynamic disks.

    NTFS only support 16TB Volume sizes using default cluster sizes, so if you need to protect any (co-located) data sources that need a larger volume, you will need to format the replica volume manually to use a larger cluster size.
    Windows VDS Service only support a maximum of 32 member spanned volumes, so to avoid bumping into that limitation (hard to do, but in theory it could bite you)  - I would not add more than 32 disks to the DPM storage pool.

    So, to sum this up,

    1) Make your LUNS any size you want not to exceed 17TB – best practice would be to convert them all to GPT so you can grow them past the 2TB size.
    2) Do not exceed the  80 TB per DPM server.  http://technet.microsoft.com/en-us/library/ff399280.aspx
    3) Do not add more the 32 disks to the DPM storage pool.


    Regards, Mike J [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Friday, August 20, 2010 3:22 PM
    Moderator
  • Hi,

    I'm new to DPM, but am looking at it to possibly protect a single volume with 20TB... With the Maximum recommendation of 17TB for the DPM server per DISK, is it still possible to protect this data?

    Unfortunately, the data is such that it can't be broken out into smaller disks.. It has to sit on a single D:\ drive :(

     

    Thanks!

    Aaron

    Thursday, October 14, 2010 5:32 PM
  • Hi Aaron,

     

    Yes, DPM can protect that 20TB volume assuming you have total free disk capacity in the DPM storage pool.  IE: You add two 17TB disks to the DPM Storage pool, DPM will automatically create a spanned volume to hold the 20TB replica volume.

     

     


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Thursday, October 14, 2010 5:47 PM
    Moderator
  • Hi,

    What kind of problems can I run into if having a disc/partition size > 17TB in DPM?

    Today I have approx. 41TB in each of my DPM storage discs/partitions & I haven't had any problems, what I know of. But I have nothing to compare with. So please give me some information about what kind of problem I can get with this configuration or what kind of benefits I can have if not exeeding 17TB.

     

    Tuesday, December 21, 2010 9:05 AM
  • Hi frav,

     

    I'm not aware of anything bad happening if you exceed the maximum 17TB Physical disk (lun) size, however, I believe that is the maximum size we tested, so that is probably the basis for the recommendation.


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Tuesday, December 21, 2010 3:01 PM
    Moderator
  • I know this is a very old thread but I'm also wondering why even with DPM 2012 the recommended maximum LUN size for DPM is 17 TB?
    Wednesday, March 27, 2013 4:08 PM
  • For DPM 2012 R2 does the Max LUN size of 17 TB still apply?  OS is Windows 2012 R2.  What consequences will I face if I have a 18TB LUN for the Storage Pool?  Thank you. 
    Thursday, April 10, 2014 6:59 PM