Files getting corrupt on tape restore - Veritas Backup Exec

This is a discussion on Files getting corrupt on tape restore - Veritas Backup Exec ; Okay, this is really weird! I just discovered today that some files are getting corrupted when restored from tape. We are using BE 9.1 on NetWare 6.5 SP4a. The tape drives are just a single HP DAT72. The backup runs ...

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  1. Files getting corrupt on tape restore


    Okay, this is really weird! I just discovered today that some files are getting
    corrupted when restored from tape. We are using BE 9.1 on NetWare 6.5 SP4a.
    The tape drives are just a single HP DAT72. The backup runs fine with NO
    errors, even with a Full Verify enabled. But when we actually restore files
    from tape those files are corrupted. Not all files, but some. I'm completely
    stumped. If the full verify has no errors, that should mean what's on tape
    matches what's on the source drive shouldn't it? And this is all using the
    same tape on the same tape drive so it's not a case of tape head misalignment
    between drives or anything. If the tape drive or tape itself were bad, I'd
    expect the full verify to fail. Oh, it's also happening on quite a few servers.
    Am I missing something that should be an obvious cause of this, or any other
    suggestions on what to look at?

  2. Re: Files getting corrupt on tape restore


    Hi Cory,
    are you good on Novells TID 2972385? This sounds like a deadlock issue between
    compression and file snapshot.
    k.m.w
    ------
    "Cory Hug" wrote:
    >
    >Okay, this is really weird! I just discovered today that some files are

    getting
    >corrupted when restored from tape. We are using BE 9.1 on NetWare 6.5 SP4a.
    > The tape drives are just a single HP DAT72. The backup runs fine with

    NO
    >errors, even with a Full Verify enabled. But when we actually restore files
    >from tape those files are corrupted. Not all files, but some. I'm completely
    >stumped. If the full verify has no errors, that should mean what's on tape
    >matches what's on the source drive shouldn't it? And this is all using

    the
    >same tape on the same tape drive so it's not a case of tape head misalignment
    >between drives or anything. If the tape drive or tape itself were bad,

    I'd
    >expect the full verify to fail. Oh, it's also happening on quite a few

    servers.
    > Am I missing something that should be an obvious cause of this, or any

    other
    >suggestions on what to look at?



  3. Re: Files getting corrupt on tape restore


    Yes, we have already applied that NSS4b update. Also, we don't use snapshot.

    "k.m.w" wrote:
    >
    >Hi Cory,
    >are you good on Novells TID 2972385? This sounds like a deadlock issue between
    >compression and file snapshot.
    >k.m.w
    >------
    >"Cory Hug" wrote:
    >>
    >>Okay, this is really weird! I just discovered today that some files are

    >getting
    >>corrupted when restored from tape. We are using BE 9.1 on NetWare 6.5

    SP4a.
    >> The tape drives are just a single HP DAT72. The backup runs fine with

    >NO
    >>errors, even with a Full Verify enabled. But when we actually restore

    files
    >>from tape those files are corrupted. Not all files, but some. I'm completely
    >>stumped. If the full verify has no errors, that should mean what's on

    tape
    >>matches what's on the source drive shouldn't it? And this is all using

    >the
    >>same tape on the same tape drive so it's not a case of tape head misalignment
    >>between drives or anything. If the tape drive or tape itself were bad,

    >I'd
    >>expect the full verify to fail. Oh, it's also happening on quite a few

    >servers.
    >> Am I missing something that should be an obvious cause of this, or any

    >other
    >>suggestions on what to look at?

    >



  4. Re: Files getting corrupt on tape restore


    Okay, after a week of testing, I have more specific info, though still no
    idea of the cause or solution.

    This is affecting ONLY Microsoft Outlook PST files. I knew PST files were
    involved when I posted the original question, but did not know it was limited
    to only PST files. After much testing I have confirmed that ONLY PST files
    are getting corrupted.

    Also, it appears to be only PST files that were open in Outlook the day that
    the backup runs. We have confirmed that the workstation PC's WERE shut down
    at the end of the day and thus the PST files were NOT locked by Outlook when
    the backup ran. (In fact, if Outlook has a PST file locked, BE skips the
    file entirely. In our case, they are getting backed up but come back off
    the tape corrupt.)

    So I know people would be tempted to say there's something with Outlook that's
    causing this, but the fact still remains the full verify of BE shows NO errors
    when the backup is run, but the files still come back off the tape corrupt
    when we actually restore them. So there's still got to be some anomaly in
    BE itself.

    Also, in not that I don't appreciate the suggestion, but in regards to the
    last suggestion on TID 2972385, since these are currently active PST files,
    they wouldn't be compressed so that shouldn't be an issue. But yes, we have
    already applied the update referred to in this TID.

    I'm still completely stumped. I just don't understand how the full verify
    in BE can say the backup is okay, but the files come back corrupt when actually
    restored, using the same tape drive. Any other ideas would be GREATLY appreciated.
    Even though it's only PST files, those are one of our most critical pieces
    of data.

    Thanks again!

    "Cory Hug" wrote:
    >
    >Yes, we have already applied that NSS4b update. Also, we don't use snapshot.
    >
    >"k.m.w" wrote:
    >>
    >>Hi Cory,
    >>are you good on Novells TID 2972385? This sounds like a deadlock issue

    between
    >>compression and file snapshot.
    >>k.m.w
    >>------
    >>"Cory Hug" wrote:
    >>>
    >>>Okay, this is really weird! I just discovered today that some files are

    >>getting
    >>>corrupted when restored from tape. We are using BE 9.1 on NetWare 6.5

    >SP4a.
    >>> The tape drives are just a single HP DAT72. The backup runs fine with

    >>NO
    >>>errors, even with a Full Verify enabled. But when we actually restore

    >files
    >>>from tape those files are corrupted. Not all files, but some. I'm completely
    >>>stumped. If the full verify has no errors, that should mean what's on

    >tape
    >>>matches what's on the source drive shouldn't it? And this is all using

    >>the
    >>>same tape on the same tape drive so it's not a case of tape head misalignment
    >>>between drives or anything. If the tape drive or tape itself were bad,

    >>I'd
    >>>expect the full verify to fail. Oh, it's also happening on quite a few

    >>servers.
    >>> Am I missing something that should be an obvious cause of this, or any

    >>other
    >>>suggestions on what to look at?

    >>

    >



  5. Re: Files getting corrupt on tape restore


    Took a long time but finally got this resolved. I ended up having to contact
    Symantec tech support and open an incident with them. They DID find an issue.
    It has to do with Sparse files. The files turned out to be okay on tape
    but were getting corrupted on restore. It turned out to be an issue with
    Novell's TSAFS.NLM. Novell has created a new TSAFS.NLM that will be included
    in their next TSA update.

    "Cory Hug" wrote:
    >
    >Okay, after a week of testing, I have more specific info, though still no
    >idea of the cause or solution.
    >
    >This is affecting ONLY Microsoft Outlook PST files. I knew PST files were
    >involved when I posted the original question, but did not know it was limited
    >to only PST files. After much testing I have confirmed that ONLY PST files
    >are getting corrupted.
    >
    >Also, it appears to be only PST files that were open in Outlook the day

    that
    >the backup runs. We have confirmed that the workstation PC's WERE shut

    down
    >at the end of the day and thus the PST files were NOT locked by Outlook

    when
    >the backup ran. (In fact, if Outlook has a PST file locked, BE skips the
    >file entirely. In our case, they are getting backed up but come back off
    >the tape corrupt.)
    >
    >So I know people would be tempted to say there's something with Outlook

    that's
    >causing this, but the fact still remains the full verify of BE shows NO

    errors
    >when the backup is run, but the files still come back off the tape corrupt
    >when we actually restore them. So there's still got to be some anomaly

    in
    >BE itself.
    >
    >Also, in not that I don't appreciate the suggestion, but in regards to the
    >last suggestion on TID 2972385, since these are currently active PST files,
    >they wouldn't be compressed so that shouldn't be an issue. But yes, we

    have
    >already applied the update referred to in this TID.
    >
    >I'm still completely stumped. I just don't understand how the full verify
    >in BE can say the backup is okay, but the files come back corrupt when actually
    >restored, using the same tape drive. Any other ideas would be GREATLY appreciated.
    > Even though it's only PST files, those are one of our most critical pieces
    >of data.
    >
    >Thanks again!
    >
    >"Cory Hug" wrote:
    >>
    >>Yes, we have already applied that NSS4b update. Also, we don't use snapshot.
    >>
    >>"k.m.w" wrote:
    >>>
    >>>Hi Cory,
    >>>are you good on Novells TID 2972385? This sounds like a deadlock issue

    >between
    >>>compression and file snapshot.
    >>>k.m.w
    >>>------
    >>>"Cory Hug" wrote:
    >>>>
    >>>>Okay, this is really weird! I just discovered today that some files

    are
    >>>getting
    >>>>corrupted when restored from tape. We are using BE 9.1 on NetWare 6.5

    >>SP4a.
    >>>> The tape drives are just a single HP DAT72. The backup runs fine with
    >>>NO
    >>>>errors, even with a Full Verify enabled. But when we actually restore

    >>files
    >>>>from tape those files are corrupted. Not all files, but some. I'm completely
    >>>>stumped. If the full verify has no errors, that should mean what's on

    >>tape
    >>>>matches what's on the source drive shouldn't it? And this is all using
    >>>the
    >>>>same tape on the same tape drive so it's not a case of tape head misalignment
    >>>>between drives or anything. If the tape drive or tape itself were bad,
    >>>I'd
    >>>>expect the full verify to fail. Oh, it's also happening on quite a few
    >>>servers.
    >>>> Am I missing something that should be an obvious cause of this, or any
    >>>other
    >>>>suggestions on what to look at?
    >>>

    >>

    >



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