slow restore times w/ Netbackup 3.2 - Veritas Net Backup

This is a discussion on slow restore times w/ Netbackup 3.2 - Veritas Net Backup ; Using Netbackup 3.2,on an IBM s80 with 6 processors as a backup server. I can backup an Exchange server at 18 Gb/hour but if I do a full restore it runs at only 6 Gb/hour. The connection to the Netbackup ...

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Thread: slow restore times w/ Netbackup 3.2

  1. slow restore times w/ Netbackup 3.2


    Using Netbackup 3.2,on an IBM s80 with 6 processors as a backup server. I
    can backup an Exchange server at 18 Gb/hour but if I do a full restore it
    runs at only 6 Gb/hour. The connection to the Netbackup setver is over a
    private gigabit ethernet.

    Another example I do a full restore of a Unix filesystem on a 4 processor
    Ibm s7a. The filesystem has 800,000 files and 80 Gigabytes of data. The connection
    to the Netbackup server is over a private gigabit ethernet. Restore runs
    at 4 Gb/hour.

    I expect restore to run a slower but 4x seems excessive.

    Is there any way I can speed this up?

    mike
    michael.mcgann@swisscom.com

  2. Re: slow restore times w/ Netbackup 3.2


    "Michael McGann" wrote:
    >
    >Using Netbackup 3.2,on an IBM s80 with 6 processors as a backup server.

    I
    >can backup an Exchange server at 18 Gb/hour but if I do a full restore it
    >runs at only 6 Gb/hour. The connection to the Netbackup setver is over a
    >private gigabit ethernet.
    >
    >Another example I do a full restore of a Unix filesystem on a 4 processor
    >Ibm s7a. The filesystem has 800,000 files and 80 Gigabytes of data. The

    connection
    >to the Netbackup server is over a private gigabit ethernet. Restore runs
    >at 4 Gb/hour.
    >
    >I expect restore to run a slower but 4x seems excessive.
    >
    >Is there any way I can speed this up?
    >
    >mike
    >michael.mcgann@swisscom.com


    We've experienced slow restore rates (direct to unix client, and over NFS
    especially) for filesystems that have 100,000+ files. Keep in mind that
    inodes have to be created, and when the average file size is only 100K, UN*X
    spends a lot of time with simple file creation, as opposed to pulling data
    down the pipe for larger files.

    If you had 80GB of data, but only 50,000 files, I would expect that your
    performance for restores would dramatically improve.

    That being said, I've also seen scenarios where ServerA->ServerB produces
    reasonable throughput, while ServerB->ServerA works at a snail's pace. In
    this case, usually duplex settings and auto-negotiation play a part in the
    cause (100BT) - but not sure if Gig.Ether would see the same. FTP tests between
    master and client would show any differences in xfer rates between nodes.
    Your mileage may vary.

    Hope this helps,
    Greg.



  3. Re: slow restore times w/ Netbackup 3.2


    We have done some more testing. It seems that part of the problem is the log
    files. If I restore a 1.6 gig file system
    with 40,000+ files it takes over an hour. If I restore it with no log file,
    it takes 15 minutes.

    The same seems to apply to backups. If I turn off all logging they seem to
    run much faster.

    The problem with restores is that if I don't get a log and the restore has
    an error all I have to find the problem is the return code.

    Any ideas on how to get log only on errors.

    mike
    "Michael McGann" wrote:
    >
    >Using Netbackup 3.2,on an IBM s80 with 6 processors as a backup server.

    I
    >can backup an Exchange server at 18 Gb/hour but if I do a full restore it
    >runs at only 6 Gb/hour. The connection to the Netbackup setver is over a
    >private gigabit ethernet.
    >
    >Another example I do a full restore of a Unix filesystem on a 4 processor
    >Ibm s7a. The filesystem has 800,000 files and 80 Gigabytes of data. The

    connection
    >to the Netbackup server is over a private gigabit ethernet. Restore runs
    >at 4 Gb/hour.
    >
    >I expect restore to run a slower but 4x seems excessive.
    >
    >Is there any way I can speed this up?
    >
    >mike
    >michael.mcgann@swisscom.com



  4. Re: slow restore times w/ Netbackup 3.2


    All--

    I have a simple question. I am experiencing slow backups. 2.5GB/hr. (+/-)
    I noticed the mention of logging causing slowness. However, I have
    not found in the docs how/where that can be specifically disabled.
    I don't have anything to the effect of logging set in the .conf
    file(s).

    I mainly use the java gui to admin NetBackup. Is it possible, that
    if one chooses to "view progress" when the backup/restore dialogue
    offers it, logging is turned on in the background? My guess is that
    it does and the progress output isn't just going to stdout. I could
    be wrong.

    Any thoughts, tips, solutions?

    TIA

    Ben

    "Michael McGann" wrote:
    >
    >Using Netbackup 3.2,on an IBM s80 with 6 processors as a backup server.

    I
    >can backup an Exchange server at 18 Gb/hour but if I do a full restore it
    >runs at only 6 Gb/hour. The connection to the Netbackup setver is over a
    >private gigabit ethernet.
    >
    >Another example I do a full restore of a Unix filesystem on a 4 processor
    >Ibm s7a. The filesystem has 800,000 files and 80 Gigabytes of data. The

    connection
    >to the Netbackup server is over a private gigabit ethernet. Restore runs
    >at 4 Gb/hour.
    >
    >I expect restore to run a slower but 4x seems excessive.
    >
    >Is there any way I can speed this up?
    >
    >mike
    >michael.mcgann@swisscom.com



  5. Re: slow restore times w/ Netbackup 3.2

    Multiplexing abuse typically causes slow restore times. For example, if you
    multiplex data from several clients onto a singe tape you will probably get
    good write throughput to that tape device. However when you perform a
    restore, NetBackup must first demultiplex the data before reconstructing it
    and writing it to disk.

    Hope this helps...

    -jlh
    Ben Batten wrote in message
    news:39117f4f@hronntp01....
    >
    > All--
    >
    > I have a simple question. I am experiencing slow backups. 2.5GB/hr.

    (+/-)
    > I noticed the mention of logging causing slowness. However, I have
    > not found in the docs how/where that can be specifically disabled.
    > I don't have anything to the effect of logging set in the .conf
    > file(s).
    >
    > I mainly use the java gui to admin NetBackup. Is it possible, that
    > if one chooses to "view progress" when the backup/restore dialogue
    > offers it, logging is turned on in the background? My guess is that
    > it does and the progress output isn't just going to stdout. I could
    > be wrong.
    >
    > Any thoughts, tips, solutions?
    >
    > TIA
    >
    > Ben
    >
    > "Michael McGann" wrote:
    > >
    > >Using Netbackup 3.2,on an IBM s80 with 6 processors as a backup server.

    > I
    > >can backup an Exchange server at 18 Gb/hour but if I do a full restore it
    > >runs at only 6 Gb/hour. The connection to the Netbackup setver is over a
    > >private gigabit ethernet.
    > >
    > >Another example I do a full restore of a Unix filesystem on a 4 processor
    > >Ibm s7a. The filesystem has 800,000 files and 80 Gigabytes of data. The

    > connection
    > >to the Netbackup server is over a private gigabit ethernet. Restore runs
    > >at 4 Gb/hour.
    > >
    > >I expect restore to run a slower but 4x seems excessive.
    > >
    > >Is there any way I can speed this up?
    > >
    > >mike
    > >michael.mcgann@swisscom.com

    >




  6. Re: slow restore times w/ Netbackup 3.2


    I just saw the feature list for Netbackup 3.4, they are promising
    a "dramatic speedup" in restore times for filesyatems with large numbers
    of files. So it seems the problem is inherent in 3.2.

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