upgrade from DLT1 to DLT7000 and backup less? - Veritas Backup Exec

This is a discussion on upgrade from DLT1 to DLT7000 and backup less? - Veritas Backup Exec ; I have just swapped out a Dell PowerVault 120T DLT1 autoloader for a PowerVault 120T DLT7000 autoloader on a BE9.0 NW6 system The DLT1 got around 48GB onto a single DLT IV tape, the DLT7000 only gets around 44GB onto ...

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Thread: upgrade from DLT1 to DLT7000 and backup less?

  1. upgrade from DLT1 to DLT7000 and backup less?

    I have just swapped out a Dell PowerVault 120T DLT1 autoloader for a PowerVault 120T DLT7000 autoloader on a BE9.0 NW6 system

    The DLT1 got around 48GB onto a single DLT IV tape, the DLT7000 only gets around 44GB onto a DLT IV tape, and I was expecting a bit increase in capacity

    tried:
    cleaned drive with cleaning tape
    brand new DLT tapes
    checking Density on drive - set at 35C, so expect up to 70GB backup
    NW drivers
    SCSI card bios

    I am backing up the same source files, throught the same server, using the same program onto a device which is supposed to support higher density and larger capacities, but I have seen a drop in capacity

    anybody have any ideas or suggestions?

    many thanks

    Simon


  2. Re: upgrade from DLT1 to DLT7000 and backup less?

    Actually, your 7000 has lower native capacity than the DLT1 (35 vs 40),
    which means the theoretical max capacity is a respective 70 vs 80. The
    advantage the 7000 has over the DLT1 is speed (3/6MBps for the DLT1 and
    5/10MBps for the 7000). Compression ratio is the same for both -- 2:1.

    Could it be the data your backup up are already compressed? If so,
    then you will not achieve additional compression via the tape hardware
    or backup software. If you calculate the size of the uncompressed data
    then that will give you a better idea how much data you are writing to
    tape.

    --

    -Barry.



  3. Re: upgrade from DLT1 to DLT7000 and backup less?

    Barry

    thanks for the reply and information, indeed most of the data is probably already compressed on the servers, hence lower totals....

    Looks like I will need to go to a Full + Differentials strategy, it has been suggested I could have two tapes for a full backup, plus one for appended differentials, and set up two weeks within one 7 slot loader, which sounds good to me

    regards
    Simon


    >>> Barry St.John 16/01/2004 17:33:35 >>>


    Actually, your 7000 has lower native capacity than the DLT1 (35 vs 40),
    which means the theoretical max capacity is a respective 70 vs 80. The
    advantage the 7000 has over the DLT1 is speed (3/6MBps for the DLT1 and
    5/10MBps for the 7000). Compression ratio is the same for both -- 2:1.

    Could it be the data your backup up are already compressed? If so,
    then you will not achieve additional compression via the tape hardware
    or backup software. If you calculate the size of the uncompressed data
    then that will give you a better idea how much data you are writing to
    tape.

    --

    -Barry.


  4. Re: upgrade from DLT1 to DLT7000 and backup less?

    Glad to be of help.
    --

    -Barry.



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