Restore speed?? - Veritas Backup Exec

This is a discussion on Restore speed?? - Veritas Backup Exec ; Question regarding restore speed (BE9.1). Our backups to AIT tape run at approx 800-900mb/min, which is great. However each time we restore stuff the restores start at around 100mb/min and then slowly, over the space of 5 mins, keep reducing ...

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Thread: Restore speed??

  1. Restore speed??

    Question regarding restore speed (BE9.1). Our backups to AIT tape run at
    approx 800-900mb/min, which is great. However each time we restore stuff
    the restores start at around 100mb/min and then slowly, over the space
    of 5 mins, keep reducing down to around 50mb/min. Sometimes it keeps
    reducing further until it gets down to 0 and we have to kill the restore.

    Any info appreciated

    TIA

  2. Re: Restore speed??

    On Wed, 08 Dec 2004 09:42:26 +1300, David Jenkins
    wrote:

    >Question regarding restore speed (BE9.1). Our backups to AIT tape run at
    >approx 800-900mb/min, which is great. However each time we restore stuff
    >the restores start at around 100mb/min and then slowly, over the space
    >of 5 mins, keep reducing down to around 50mb/min. Sometimes it keeps
    >reducing further until it gets down to 0 and we have to kill the restore.


    Well, apart from the cases where you have to kill the job, that seems
    about par for the course in my experience. Restores are often roughly
    10 times slower than backups (with Backup Exec and other software
    designed around tape). I've wondered why and asked why many times,
    but I've never had a decent answer.

    Try working out how long it takes to do a full backup of all your
    systems, and then multiply it by ten to get the time to do a complete
    restore of all systems in case of catastrophe...some food for thought
    probably. Some of the more modern solutions out there, especially
    those designed around disk-based backup can reduce these times
    dramatically.

    Roger

  3. Re: Restore speed??

    Roger J wrote:
    > On Wed, 08 Dec 2004 09:42:26 +1300, David Jenkins
    > wrote:
    >
    >
    >>Question regarding restore speed (BE9.1). Our backups to AIT tape run at
    >>approx 800-900mb/min, which is great. However each time we restore stuff
    >>the restores start at around 100mb/min and then slowly, over the space
    >>of 5 mins, keep reducing down to around 50mb/min. Sometimes it keeps
    >>reducing further until it gets down to 0 and we have to kill the restore.

    >
    >
    > Well, apart from the cases where you have to kill the job, that seems
    > about par for the course in my experience. Restores are often roughly
    > 10 times slower than backups (with Backup Exec and other software
    > designed around tape). I've wondered why and asked why many times,
    > but I've never had a decent answer.
    >
    > Try working out how long it takes to do a full backup of all your
    > systems, and then multiply it by ten to get the time to do a complete
    > restore of all systems in case of catastrophe...some food for thought
    > probably. Some of the more modern solutions out there, especially
    > those designed around disk-based backup can reduce these times
    > dramatically.
    >
    > Roger



    I also have noticed this 10:1 ratio

    I was told a long time ago that backups are faster because the OS
    buffers the reads, and the data is streamed to the tape as a single
    file. Restores on the other hand, can buffer reads, somewhat, but for
    every separate file restored, the File System must be updated with all
    pertinent info, and the old file if it exists, must be deleted.

    Don't recall who told me this (one of the Veritas techs I was working a
    problem with, I think), but it does make sense, no?

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