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DPM 2010 and Storage Pools... RRS feed

  • Question

  • I have a Customer who wants to use 1 large 14TB disk to put in a DPM Storage Pool. The physical storage system can only create 2TB LUN's, and so to DPM, it can see 7ea 2TB disks that can be added. What is the advantage/disadvantage to using only 1 large 14TB disk, rather than 7ea 2TB disks?
    Matthew Gayle
    Wednesday, May 18, 2011 9:50 AM

Answers

  • Hi laith_IT,

    <snip>
    You have to take into consideration Windows 2008 limitation which is not more than 16 TB for one disk.
    >snip<

    I think you are confusing "disk" with "volume"  - Windows has a default limit of 16TB for a single NTFS Volume using a 4K cluster size.   That volume can be a spanned volume across several smaller physical (dynamic) disks, or a single partition on a >16TB GPT disk.

    DPM has a tested limit of 80TB in the DPM storage pool and a tested limit of 17TB per GPT Disk.  MBR disks have a physical size limit of 2TB - so if you start with 2TB physical disks (LUN) and plan on growing the LUN beyond 2TB, then make sure you convert the disk from MBR to GPT before adding it to the DPM storage  pool. 


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Monday, September 19, 2011 11:55 PM
    Moderator

All replies

  • I have a Customer who wants to use 1 large 14TB disk to put in a DPM Storage Pool. The physical storage system can only create 2TB LUN's, and so to DPM, it can see 7ea 2TB disks that can be added. What is the advantage/disadvantage to using only 1 large 14TB disk, rather than 7ea 2TB disks?
    Matthew Gayle

    recommendation from http://technet.microsoft.com/en-us/library/ff399365.aspx 

    "We recommend that you use disks that have capacity of no more than 1.5 terabytes. Because a dynamic volume can span up to 32 disks, if you use 1.5-terabyte disks, DPM can create replica volumes of up to 48 terabytes."


    Грамотная постановка вопроса - уже 50% решения. Не забывайте помечать ответы как полезные или как ответ, если они Вам помогли.
    Thursday, May 19, 2011 8:59 AM
  • I, too , have read the notes on DPM and storage considerations. I'm trying to find out why they recommend 1.5TB (maximum) and not higher. Is there no difference if I use either 1ea 14TB disk or 7ea 2TB disks? What issues arise if I use 2TB disks rather than 1.5TB disks? My Customer has decided to use 2TB disks and DPM seems to be running fine...it's only been 48 hours, but if there is some risk with the 2TB disks, I would like to find out here or be pointed to existing documentation from MS.


    Matthew Gayle
    Thursday, May 19, 2011 6:16 PM
  • You can disregard the article about the 1.5TB limit, that is now obsolete and inaccurate - new guidelines are are posted here:
    http://technet.microsoft.com/en-us/library/ff399280.aspx

     


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Saturday, May 28, 2011 10:05 PM
    Moderator
  • No problem performing 2 TB disks.

    I have more than 100 TB of data to protect and im using 2 TB disks and no problem at all.

    You have to take into consideration Windows 2008 limitation which is not more than 16 TB for one disk.

    You can connect 14 TB to the DPM and no problems at all. You have to make sure how to plan the connection, DAS or ISCSI and you have to take into consideration that the storage support Dynamic Disk since its the only technology that the DPM using.

     

    Hope that helps,

    Laith.

    Friday, September 16, 2011 2:03 PM
  • Hi laith_IT,

    <snip>
    You have to take into consideration Windows 2008 limitation which is not more than 16 TB for one disk.
    >snip<

    I think you are confusing "disk" with "volume"  - Windows has a default limit of 16TB for a single NTFS Volume using a 4K cluster size.   That volume can be a spanned volume across several smaller physical (dynamic) disks, or a single partition on a >16TB GPT disk.

    DPM has a tested limit of 80TB in the DPM storage pool and a tested limit of 17TB per GPT Disk.  MBR disks have a physical size limit of 2TB - so if you start with 2TB physical disks (LUN) and plan on growing the LUN beyond 2TB, then make sure you convert the disk from MBR to GPT before adding it to the DPM storage  pool. 


    Regards, Mike J. [MSFT] This posting is provided "AS IS" with no warranties, and confers no rights.
    Monday, September 19, 2011 11:55 PM
    Moderator
  • Thanks Mike for the info.

    Just want to inform you that I've tried to present 17 TB GPT signle disk to Windows one time and Windows only saw 16 TB. But i was able to present several 16 TB GPT disks to windows.

    When you increase the LUN its better to disconnect the ISCSI from the server, increase it on the storage and then reconnect it to windows otherwise Windows might see this increased disk as a new disk and not as expanded disk.

    Tuesday, September 20, 2011 5:28 AM