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DPM 2012 Queries RRS feed

  • Question

  • Hi,

    Can anyone help me with proper meaning of below sentences.

    1. Short-term or long-term backup to tape will be limited to using iSCSI attached tape libraries, and we recommend a separate NIC for that connection.
    2. 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.  My query here is that can't we use disk having more than 1.5 TB in size? though we required.

    Thanks in advance.

    Regards,

    Parag

    Friday, May 4, 2012 6:41 PM

Answers

  • Hi,

    Statement 1 - Short-term or long-term backup to tape will be limited to using iSCSI attached tape libraries, and we recommend a separate NIC for that connection.

    Answer 1 - That statement is true only when you are running DPM in a Hyper-V Virtual machine.  In Hyper-V you cannot connect a physical tape library to a scsi, usb, or fiber port, so iSCSI the only way to connect a tape library.

    Statement 2 -  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. My query here is that can't we use disk having more than 1.5 TB in size? though we required.

    Answer 2 -  That was very old and not very accurate guidance and seems to be wrong on technet page for DPM 2012 also.

    See this page instead http://technet.microsoft.com/en-us/library/ff399280.aspx

    A) Maximum of 17 TB for GUID partition table (GPT) dynamic disks
    B) 2 TB for master boot record (MBR) disks
    C) 80 TB per DPM server, with a maximum recovery point size of 40 TB


    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.

    Saturday, May 5, 2012 9:44 PM
    Moderator
  • Hi,

    Windows support 4 types of physical disks.

    Master Boot record (MBR) Disk is the traditional disk that supports Primary / Extended partitions.  This type of disk has a size limitation of 2TB due to the partition table structure used to describe partitions.

    Globally Unique ID Partition Table (GPT) disk is a disk that does not use the traditional MBR partition tables, and instead uses a new set of tables and allows for very large physical disks and partitions beyond the 2TB limitatiion of MBR disks.

    Then we have Dynamic disk support for both of the above.

    If you plan on making or growing a SAN or raid array disk greater than 2TB, then convert the disk to GPT before adding it to the DPM storage pool.   Once a volume is created on a MBR disk, that disk cannot be converted to GPT later without first deleting all the volumes, so it's important to convert it when it's all unallocated free space.


    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 Parag_M Tuesday, May 8, 2012 12:32 PM
    Monday, May 7, 2012 3:20 PM
    Moderator

All replies

  • Hi,

    Statement 1 - Short-term or long-term backup to tape will be limited to using iSCSI attached tape libraries, and we recommend a separate NIC for that connection.

    Answer 1 - That statement is true only when you are running DPM in a Hyper-V Virtual machine.  In Hyper-V you cannot connect a physical tape library to a scsi, usb, or fiber port, so iSCSI the only way to connect a tape library.

    Statement 2 -  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. My query here is that can't we use disk having more than 1.5 TB in size? though we required.

    Answer 2 -  That was very old and not very accurate guidance and seems to be wrong on technet page for DPM 2012 also.

    See this page instead http://technet.microsoft.com/en-us/library/ff399280.aspx

    A) Maximum of 17 TB for GUID partition table (GPT) dynamic disks
    B) 2 TB for master boot record (MBR) disks
    C) 80 TB per DPM server, with a maximum recovery point size of 40 TB


    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.

    Saturday, May 5, 2012 9:44 PM
    Moderator
  • Thanks Mike for your reply.

    Could you please elaborate below 2 statement from your ans no.2 since I don't have much more knowledge on storage.

    A) Maximum of 17 TB for GUID partition table (GPT) dynamic disks
    B) 2 TB for master boot record (MBR) disks

    Sunday, May 6, 2012 11:09 AM
  • Hi,

    Windows support 4 types of physical disks.

    Master Boot record (MBR) Disk is the traditional disk that supports Primary / Extended partitions.  This type of disk has a size limitation of 2TB due to the partition table structure used to describe partitions.

    Globally Unique ID Partition Table (GPT) disk is a disk that does not use the traditional MBR partition tables, and instead uses a new set of tables and allows for very large physical disks and partitions beyond the 2TB limitatiion of MBR disks.

    Then we have Dynamic disk support for both of the above.

    If you plan on making or growing a SAN or raid array disk greater than 2TB, then convert the disk to GPT before adding it to the DPM storage pool.   Once a volume is created on a MBR disk, that disk cannot be converted to GPT later without first deleting all the volumes, so it's important to convert it when it's all unallocated free space.


    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 Parag_M Tuesday, May 8, 2012 12:32 PM
    Monday, May 7, 2012 3:20 PM
    Moderator
  • Thanks Mike.

    Tuesday, May 8, 2012 12:33 PM