What's the most likely backup format? - VMS

This is a discussion on What's the most likely backup format? - VMS ; I have a DLT III tape that was written to on a VMS system. That's all I know. Is it possible to scan this tape looking for data? I guess my question is, what format was the data, that was ...

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  1. What's the most likely backup format?

    I have a DLT III tape that was written to on a VMS system. That's all
    I know. Is it possible to scan this tape looking for data? I guess
    my question is, what format was the data, that was most likely written
    to the tape? I know nothing about VMS or DEC hardware. I'm a Unix and
    Windows guy and want to try and recover some data off of this tape,
    but i'm thinking that it's in some proprietary format?

    I know there are a lot of variables with this open ended question, but
    it's worth a try.

    Thanks to all who reply.

    -fd

  2. Re: What's the most likely backup format?

    forest demon wrote:
    > I have a DLT III tape that was written to on a VMS system. That's all
    > I know. Is it possible to scan this tape looking for data?


    Most likely is that it is an ANSI tape with a single file in it. That
    file would be a BACKUP saveset, a VMS proprietary format.

    There are a couple of open sources to read backup formats.

    Last one I spotted was at http://www.hoffmanlabs.com (from there, jump
    to the new site) and there is one for OS-X (should compile on unix).

    If not, you then have to get someone to read the tape for you and unpack
    it from BACKUP and repack it with ZIP or TAR.

  3. Re: What's the most likely backup format?

    On May 6, 12:57*am, forest demon wrote:
    > I have a DLT III tape that was written to on a VMS system. *That's all
    > I know. *Is it possible to scan this tape looking for data? *I guess
    > my question is, what format was the data, that was most likely written
    > to the tape?


    If the tape was written with the expectation that it would be read by
    a non-VMS system, then it may have plain old ANSI labels and blocked
    data. There are lots of ways to write a tape on VMS so that another
    system can read the data, and vice-versa.

    The trick part -- whether it was written with an interchange format or
    a proprietary VMS BACKUP format -- is to figure out the blocking.
    That's a parameter that can be changed from tape-to-tape so guessing
    at what it might be is going to be a headache.

  4. Re: What's the most likely backup format?

    forest demon wrote:
    > I have a DLT III tape that was written to on a VMS system. That's all
    > I know. Is it possible to scan this tape looking for data? I guess
    > my question is, what format was the data, that was most likely written
    > to the tape? I know nothing about VMS or DEC hardware. I'm a Unix and
    > Windows guy and want to try and recover some data off of this tape,
    > but i'm thinking that it's in some proprietary format?
    >
    > I know there are a lot of variables with this open ended question, but
    > it's worth a try.
    >
    > Thanks to all who reply.
    >
    > -fd


    It's most likely that the tape contains one or more VMS Backup savesets.

    If you have a DLT-III, or better, tape drive you should be able to dump
    out the ANSI tape label and the first couple of records. If, as I
    suspect, a backup tape it will have the text of the backup command in
    the first block following the label records.


  5. Re: What's the most likely backup format?

    On May 6, 7:44*am, koeh...@eisner.nospam.encompasserve.org (Bob
    Koehler) wrote:
    > In article <99b93071-031a-4e9c-bf91-bec1a8be8...@u36g2000prf.googlegroups.com>, forest demon writes:
    >
    > > I have a DLT III tape that was written to on a VMS system.

    >
    > * *If you have a DLT III drive on your UNIX system, you can scan
    > * *the tape to get some ieda of what is on it by using od.
    >
    > * *It may be an ASCI/ANSI labeled tape, and your UNIX may have ltf
    > * *which will read such tapes if they are single volume. *Or it
    > * *may be a tar, a VMS BACKUP, raw data files, EBCDIC, ...
    >
    > * *In short VMS can read and write just about anything. *The only
    > * *thing you'll have trouble with is a VMS BACKUP format, since there
    > * *are no native utilities on UNIX to read that. *There are
    > * *commercially available tools, and there are folks who will read it
    > * *on a VMS system for you and put it i some format you like.
    >
    > * *I'd start with od and see if there are labels on the tape. *If the
    > * *labels include the string "BACKUP" then its probably VMS BACKUP.
    > * *If not, labels might by ANSI/ASCII or EBCDIC SL. *If there are
    > * *no labels then look at the format tar generates and see if it matches
    > * *that, then try cpio format, ...
    >
    > * *One of my favorite starting points for this is a little program I
    > * *have that tries to read the maximum block size, reports back to me
    > * *how many actual blocks and their actual size, and how many file
    > * *marks (two consecutive EOF marks means logical end of volume).
    >
    > * *That and some familiarity with various formats generally gets me
    > * *going.


    Thanks to all who replied. I truly appreciate your time!

    -fd

  6. Re: What's the most likely backup format?

    In article <99b93071-031a-4e9c-bf91-bec1a8be8110@u36g2000prf.googlegroups.com>, forest demon writes:
    > I have a DLT III tape that was written to on a VMS system.


    If you have a DLT III drive on your UNIX system, you can scan
    the tape to get some ieda of what is on it by using od.

    It may be an ASCI/ANSI labeled tape, and your UNIX may have ltf
    which will read such tapes if they are single volume. Or it
    may be a tar, a VMS BACKUP, raw data files, EBCDIC, ...

    In short VMS can read and write just about anything. The only
    thing you'll have trouble with is a VMS BACKUP format, since there
    are no native utilities on UNIX to read that. There are
    commercially available tools, and there are folks who will read it
    on a VMS system for you and put it i some format you like.

    I'd start with od and see if there are labels on the tape. If the
    labels include the string "BACKUP" then its probably VMS BACKUP.
    If not, labels might by ANSI/ASCII or EBCDIC SL. If there are
    no labels then look at the format tar generates and see if it matches
    that, then try cpio format, ...

    One of my favorite starting points for this is a little program I
    have that tries to read the maximum block size, reports back to me
    how many actual blocks and their actual size, and how many file
    marks (two consecutive EOF marks means logical end of volume).

    That and some familiarity with various formats generally gets me
    going.


  7. Re: What's the most likely backup format?

    JF Mezei wrote:
    > forest demon wrote:
    >> I have a DLT III tape that was written to on a VMS system. That's all
    >> I know. Is it possible to scan this tape looking for data?

    >
    > Most likely is that it is an ANSI tape with a single file in it. That
    > file would be a BACKUP saveset, a VMS proprietary format.
    >
    > There are a couple of open sources to read backup formats.
    >
    > Last one I spotted was at http://www.hoffmanlabs.com (from there, jump
    > to the new site) and there is one for OS-X (should compile on unix).
    >
    > If not, you then have to get someone to read the tape for you and unpack
    > it from BACKUP and repack it with ZIP or TAR.


    I would say that chances are good that will be a lot faster.

    Arne

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