backup to DVD-RAM - Linux

This is a discussion on backup to DVD-RAM - Linux ; I've been pulling my hair out over this one. Things just don't seem to be working the way I think they should. I'm trying to do a backup to a DVD-RAM disk in an LG DVD writer. When I do ...

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Thread: backup to DVD-RAM

  1. backup to DVD-RAM

    I've been pulling my hair out over this one. Things just don't seem to
    be working the way I think they should.

    I'm trying to do a backup to a DVD-RAM disk in an LG DVD writer. When I
    do a dvd+rw-format -blank -force /dev/dvd, mounting the dvd afterwards
    shows that no blanking took place. Even ejecting it and remounting it
    doesn't change that.

    growisofs -Z /dev/dvd backups/* also seems to fail when I run it in a
    script as a cron job (run as root). I can run it from the command line
    as root however and it successfully overwrites the old data after
    warning me that the device already contains an isofs.

    This one I traced to a section in the growisofs howto that says that
    this is how it is supposed to act! It aborts with a fatal error if it is
    asked to -Z an iso9660 file system non-interactively. And there
    doesn't seem to be a switch to override this behaviour.

    The impact of these two issues seems to be that I can't just blank the
    disc then put a new backup on it. What I'm trying now is to make a
    different filesystem on /dev/dvd then let growisofs do its thing.
    Apparently this should work?!

    Questions:
    - why doesn't dvd+rw-format blank a DVD-RAM disk?
    - why doesn't growisofs let me zero an iso-formatted disk?

    Any ideas anyone?

  2. Re: backup to DVD-RAM

    Gary Dale wrote:
    > I've been pulling my hair out over this one. Things just don't seem to
    > be working the way I think they should.
    >
    > I'm trying to do a backup to a DVD-RAM disk in an LG DVD writer. When I
    > do a dvd+rw-format -blank -force /dev/dvd, mounting the dvd afterwards
    > shows that no blanking took place. Even ejecting it and remounting it
    > doesn't change that.
    >
    > growisofs -Z /dev/dvd backups/* also seems to fail when I run it in a
    > script as a cron job (run as root). I can run it from the command line
    > as root however and it successfully overwrites the old data after
    > warning me that the device already contains an isofs.
    >
    > This one I traced to a section in the growisofs howto that says that
    > this is how it is supposed to act! It aborts with a fatal error if it is
    > asked to -Z an iso9660 file system non-interactively. And there
    > doesn't seem to be a switch to override this behaviour.
    >
    > The impact of these two issues seems to be that I can't just blank the
    > disc then put a new backup on it. What I'm trying now is to make a
    > different filesystem on /dev/dvd then let growisofs do its thing.
    > Apparently this should work?!
    >
    > Questions:
    > - why doesn't dvd+rw-format blank a DVD-RAM disk?


    Because it's not a DVD+ format? Why would you even want to do this? A
    dvd-ram acts like a slow hard drive, it doesn't need to be erased to
    write to it.

    > - why doesn't growisofs let me zero an iso-formatted disk?
    >
    > Any ideas anyone?


    Try UDF as a FS, it's designed for DVD's.

    Jerry


  3. Re: backup to DVD-RAM

    Jerry Peters wrote:
    > Gary Dale wrote:
    >> I've been pulling my hair out over this one. Things just don't seem to
    >> be working the way I think they should.
    >>
    >> I'm trying to do a backup to a DVD-RAM disk in an LG DVD writer. When I
    >> do a dvd+rw-format -blank -force /dev/dvd, mounting the dvd afterwards
    >> shows that no blanking took place. Even ejecting it and remounting it
    >> doesn't change that.
    >>
    >> growisofs -Z /dev/dvd backups/* also seems to fail when I run it in a
    >> script as a cron job (run as root). I can run it from the command line
    >> as root however and it successfully overwrites the old data after
    >> warning me that the device already contains an isofs.
    >>
    >> This one I traced to a section in the growisofs howto that says that
    >> this is how it is supposed to act! It aborts with a fatal error if it is
    >> asked to -Z an iso9660 file system non-interactively. And there
    >> doesn't seem to be a switch to override this behaviour.
    >>
    >> The impact of these two issues seems to be that I can't just blank the
    >> disc then put a new backup on it. What I'm trying now is to make a
    >> different filesystem on /dev/dvd then let growisofs do its thing.
    >> Apparently this should work?!
    >>
    >> Questions:
    >> - why doesn't dvd+rw-format blank a DVD-RAM disk?

    >
    > Because it's not a DVD+ format? Why would you even want to do this? A
    > dvd-ram acts like a slow hard drive, it doesn't need to be erased to
    > write to it.


    from the dvd+rw-format man page:
    dvd+rw-format - format DVD+-RW/-RAM disk

    It doesn't need to be erased but it does need to have a file system put
    on it. Since I don't know if a new disk has been put in or not, the
    simplest solution is to format whatever is there.

    Of course, my second question (below) makes the issue moot. I have to
    blank it with a non-iso file system or growisofs fails. Still, I would
    like to know what's going on.


    >
    >> - why doesn't growisofs let me zero an iso-formatted disk?
    >>
    >> Any ideas anyone?

    >
    > Try UDF as a FS, it's designed for DVD's.


    Yes, but it's not well supported in Linux from what I've been reading.
    And working with UDF seems more trouble than simply using growisofs. The
    issue is, why does growisofs object so strongly to writing to an already
    formatted disk? The write fails if not done interactively and you can't
    override that behaviour.

    Note that I can't guarantee that the disk that is placed in the drive is
    a previous backup disk any more than I can guarantee is it a new disk.
    It could contain anything so I have to erase it to ensure there is room
    for the backup files.

    The end result is that I have to blank the disk before using it, or
    detect whether it has already been written to and replace the -Z with
    something else that will achieve the same end. The simplest thing is to
    just blank it - but not using an iso format.


    >
    > Jerry
    >


  4. Re: backup to DVD-RAM

    Gary Dale wrote:
    > Jerry Peters wrote:
    >> Gary Dale wrote:
    >>> I've been pulling my hair out over this one. Things just don't seem to
    >>> be working the way I think they should.
    >>>
    >>> I'm trying to do a backup to a DVD-RAM disk in an LG DVD writer. When I
    >>> do a dvd+rw-format -blank -force /dev/dvd, mounting the dvd afterwards
    >>> shows that no blanking took place. Even ejecting it and remounting it
    >>> doesn't change that.
    >>>
    >>> growisofs -Z /dev/dvd backups/* also seems to fail when I run it in a
    >>> script as a cron job (run as root). I can run it from the command line
    >>> as root however and it successfully overwrites the old data after
    >>> warning me that the device already contains an isofs.
    >>>
    >>> This one I traced to a section in the growisofs howto that says that
    >>> this is how it is supposed to act! It aborts with a fatal error if it is
    >>> asked to -Z an iso9660 file system non-interactively. And there
    >>> doesn't seem to be a switch to override this behaviour.
    >>>
    >>> The impact of these two issues seems to be that I can't just blank the
    >>> disc then put a new backup on it. What I'm trying now is to make a
    >>> different filesystem on /dev/dvd then let growisofs do its thing.
    >>> Apparently this should work?!
    >>>
    >>> Questions:
    >>> - why doesn't dvd+rw-format blank a DVD-RAM disk?

    >>
    >> Because it's not a DVD+ format? Why would you even want to do this? A
    >> dvd-ram acts like a slow hard drive, it doesn't need to be erased to
    >> write to it.

    >
    > from the dvd+rw-format man page:
    > dvd+rw-format - format DVD+-RW/-RAM disk
    >
    > It doesn't need to be erased but it does need to have a file system put
    > on it. Since I don't know if a new disk has been put in or not, the
    > simplest solution is to format whatever is there.
    >

    My experience has been that _every_ new DVD-RAM I've bought has a UDF
    FS on it. Formatting and making a FS are not the same operations, BTW.

    > Of course, my second question (below) makes the issue moot. I have to
    > blank it with a non-iso file system or growisofs fails. Still, I would
    > like to know what's going on.
    >
    >
    >>
    >>> - why doesn't growisofs let me zero an iso-formatted disk?
    >>>
    >>> Any ideas anyone?

    >>
    >> Try UDF as a FS, it's designed for DVD's.

    >
    > Yes, but it's not well supported in Linux from what I've been reading.
    > And working with UDF seems more trouble than simply using growisofs. The
    > issue is, why does growisofs object so strongly to writing to an already
    > formatted disk? The write fails if not done interactively and you can't
    > override that behaviour.


    I've never had any problems, other than DVD-RAM tends to be slow and a
    large amount of buffered writes tend to build up (fixed by mounting
    with the sync option).

    What's the "trouble" with working with UDF? My DVD-RAM mounts on
    /dev/sr0 in rw mode and I copy data to it, just as if it were a large
    floppy. That's the advantage of DVD-RAM over the other DVD whatevers,
    it behaves like a large floppy, no special formatting required.

    If you really must use growisofs, get the source and change it to your
    needs then.

    >
    > Note that I can't guarantee that the disk that is placed in the drive is
    > a previous backup disk any more than I can guarantee is it a new disk.
    > It could contain anything so I have to erase it to ensure there is room
    > for the backup files.
    >
    > The end result is that I have to blank the disk before using it, or
    > detect whether it has already been written to and replace the -Z with
    > something else that will achieve the same end. The simplest thing is to
    > just blank it - but not using an iso format.
    >

    Perhaps a bit slow, but "rm -rf /mount-point/*" or mkudffs
    /dev/whatever.
    >
    >>
    >> Jerry
    >>


  5. Re: backup to DVD-RAM

    Jerry Peters wrote:
    > Gary Dale wrote:
    >> Jerry Peters wrote:
    >>> Gary Dale wrote:
    >>>> I've been pulling my hair out over this one. Things just don't seem to
    >>>> be working the way I think they should.
    >>>>
    >>>> I'm trying to do a backup to a DVD-RAM disk in an LG DVD writer. When I
    >>>> do a dvd+rw-format -blank -force /dev/dvd, mounting the dvd afterwards
    >>>> shows that no blanking took place. Even ejecting it and remounting it
    >>>> doesn't change that.
    >>>>
    >>>> growisofs -Z /dev/dvd backups/* also seems to fail when I run it in a
    >>>> script as a cron job (run as root). I can run it from the command line
    >>>> as root however and it successfully overwrites the old data after
    >>>> warning me that the device already contains an isofs.
    >>>>
    >>>> This one I traced to a section in the growisofs howto that says that
    >>>> this is how it is supposed to act! It aborts with a fatal error if it is
    >>>> asked to -Z an iso9660 file system non-interactively. And there
    >>>> doesn't seem to be a switch to override this behaviour.
    >>>>
    >>>> The impact of these two issues seems to be that I can't just blank the
    >>>> disc then put a new backup on it. What I'm trying now is to make a
    >>>> different filesystem on /dev/dvd then let growisofs do its thing.
    >>>> Apparently this should work?!
    >>>>
    >>>> Questions:
    >>>> - why doesn't dvd+rw-format blank a DVD-RAM disk?
    >>> Because it's not a DVD+ format? Why would you even want to do this? A
    >>> dvd-ram acts like a slow hard drive, it doesn't need to be erased to
    >>> write to it.

    >> from the dvd+rw-format man page:
    >> dvd+rw-format - format DVD+-RW/-RAM disk
    >>
    >> It doesn't need to be erased but it does need to have a file system put
    >> on it. Since I don't know if a new disk has been put in or not, the
    >> simplest solution is to format whatever is there.
    >>

    > My experience has been that _every_ new DVD-RAM I've bought has a UDF
    > FS on it. Formatting and making a FS are not the same operations, BTW.


    You're right if you're talking about a low level. However, people
    generally use them interchangeably these days. Even MS-DOS had a
    quick-format option which just put a clean directory structure on the disk.


    >
    >> Of course, my second question (below) makes the issue moot. I have to
    >> blank it with a non-iso file system or growisofs fails. Still, I would
    >> like to know what's going on.
    >>
    >>
    >>>> - why doesn't growisofs let me zero an iso-formatted disk?
    >>>>
    >>>> Any ideas anyone?
    >>> Try UDF as a FS, it's designed for DVD's.

    >> Yes, but it's not well supported in Linux from what I've been reading.
    >> And working with UDF seems more trouble than simply using growisofs. The
    >> issue is, why does growisofs object so strongly to writing to an already
    >> formatted disk? The write fails if not done interactively and you can't
    >> override that behaviour.

    >
    > I've never had any problems, other than DVD-RAM tends to be slow and a
    > large amount of buffered writes tend to build up (fixed by mounting
    > with the sync option).
    >
    > What's the "trouble" with working with UDF? My DVD-RAM mounts on
    > /dev/sr0 in rw mode and I copy data to it, just as if it were a large
    > floppy. That's the advantage of DVD-RAM over the other DVD whatevers,
    > it behaves like a large floppy, no special formatting required.
    >
    > If you really must use growisofs, get the source and change it to your
    > needs then.

    As it turns out, I decided to mkudffs to remove the growisofs problem,
    so I have everything I need to use DVD-RAM that way. However, growisofs
    works too and if ain't broke...

    And I definitely would not want to run a specially patched version of
    growisofs. I just don't get why it would have that behaviour hard-coded.
    For DVD-RAM, it's not that big a deal, but it definitely shortens the
    lifespan of DVD+-RWs when used this way.

    >
    >> Note that I can't guarantee that the disk that is placed in the drive is
    >> a previous backup disk any more than I can guarantee is it a new disk.
    >> It could contain anything so I have to erase it to ensure there is room
    >> for the backup files.
    >>
    >> The end result is that I have to blank the disk before using it, or
    >> detect whether it has already been written to and replace the -Z with
    >> something else that will achieve the same end. The simplest thing is to
    >> just blank it - but not using an iso format.
    >>

    > Perhaps a bit slow, but "rm -rf /mount-point/*" or mkudffs
    > /dev/whatever.

    Which is what I've been doing - of course mk also
    works, but mkudffs is quick.

  6. Re: backup to DVD-RAM

    Jerry Peters wrote:

    > I've never had any problems, other than DVD-RAM tends to be slow and a
    > large amount of buffered writes tend to build up (fixed by mounting
    > with the sync option).
    >
    > What's the "trouble" with working with UDF? My DVD-RAM mounts on
    > /dev/sr0 in rw mode and I copy data to it, just as if it were a large
    > floppy. That's the advantage of DVD-RAM over the other DVD whatevers,
    > it behaves like a large floppy, no special formatting required.
    >
    > If you really must use growisofs, get the source and change it to your
    > needs then.
    >

    I actually just tried using UDF directly and I found what the problem
    is.

    It appears that there is a bug in UDF support that isn't fixed until
    2.6.22 (this is from the Wikipedia -
    http://en.wikipedia.org/wiki/Universal_Disk_Format) that limits you to
    file sizes of no more than 1G. I tarred and zipped the files before
    backing them up to save space (even then the tarball is almost 3G), so
    my backups failed.

    Still, the growisofs problem of wanting a clean disk bugged me, so I've
    switched over to ext2 for now. I test for a file system by trying to
    mount it as ext2. If it fails, I format it then mount it.

    Of course, this is not the file system anyone expects on a DVD-RAM disk,
    so I will give UDF a try again when Debian/lenny becomes the new stable
    release in a couple of years.

  7. Re: backup to DVD-RAM

    Gary Dale wrote:
    > Jerry Peters wrote:
    >
    >> I've never had any problems, other than DVD-RAM tends to be slow and a
    >> large amount of buffered writes tend to build up (fixed by mounting
    >> with the sync option).
    >>
    >> What's the "trouble" with working with UDF? My DVD-RAM mounts on
    >> /dev/sr0 in rw mode and I copy data to it, just as if it were a large
    >> floppy. That's the advantage of DVD-RAM over the other DVD whatevers,
    >> it behaves like a large floppy, no special formatting required.
    >>
    >> If you really must use growisofs, get the source and change it to your
    >> needs then.
    >>

    > I actually just tried using UDF directly and I found what the problem
    > is.
    >
    > It appears that there is a bug in UDF support that isn't fixed until
    > 2.6.22 (this is from the Wikipedia -
    > http://en.wikipedia.org/wiki/Universal_Disk_Format) that limits you to
    > file sizes of no more than 1G. I tarred and zipped the files before
    > backing them up to save space (even then the tarball is almost 3G), so
    > my backups failed.
    >
    > Still, the growisofs problem of wanting a clean disk bugged me, so I've
    > switched over to ext2 for now. I test for a file system by trying to
    > mount it as ext2. If it fails, I format it then mount it.
    >
    > Of course, this is not the file system anyone expects on a DVD-RAM disk,
    > so I will give UDF a try again when Debian/lenny becomes the new stable
    > release in a couple of years.


    I'm back to about the only method that seems to be reliable.
    - mkudffs /dev/dvd -- to blank the DVD-RAM so growisofs will use it
    - growisofs -Z /dev/dvd /backups

    For some unknown reason, mke2fs /dev/dvd fails, or if it succeeds, it is
    unreliable for writing. I may or may not get a complete cp /backups/*
    /media/dvd but even if I do, I may not be able to mount it again. And
    even if I can mount it again, there is no guarantee that subsequent cp's
    will work.

    In short, working with DVD-RAM seems to be an exercise in frustration
    even though it is the only game in town for doing repetitive backups.
    It's supposed ability to be usable just like a hard disk is a myth, at
    least until kernel 2.16.22.

  8. Re: backup to DVD-RAM

    Gary Dale wrote:
    > Gary Dale wrote:
    >> Jerry Peters wrote:
    >>
    >>> I've never had any problems, other than DVD-RAM tends to be slow and a
    >>> large amount of buffered writes tend to build up (fixed by mounting
    >>> with the sync option).
    >>>
    >>> What's the "trouble" with working with UDF? My DVD-RAM mounts on
    >>> /dev/sr0 in rw mode and I copy data to it, just as if it were a large
    >>> floppy. That's the advantage of DVD-RAM over the other DVD whatevers,
    >>> it behaves like a large floppy, no special formatting required.
    >>>
    >>> If you really must use growisofs, get the source and change it to your
    >>> needs then.
    >>>

    >> I actually just tried using UDF directly and I found what the problem
    >> is.
    >>
    >> It appears that there is a bug in UDF support that isn't fixed until
    >> 2.6.22 (this is from the Wikipedia -
    >> http://en.wikipedia.org/wiki/Universal_Disk_Format) that limits you to
    >> file sizes of no more than 1G. I tarred and zipped the files before
    >> backing them up to save space (even then the tarball is almost 3G), so
    >> my backups failed.
    >>
    >> Still, the growisofs problem of wanting a clean disk bugged me, so I've
    >> switched over to ext2 for now. I test for a file system by trying to
    >> mount it as ext2. If it fails, I format it then mount it.
    >>
    >> Of course, this is not the file system anyone expects on a DVD-RAM disk,
    >> so I will give UDF a try again when Debian/lenny becomes the new stable
    >> release in a couple of years.

    >
    > I'm back to about the only method that seems to be reliable.
    > - mkudffs /dev/dvd -- to blank the DVD-RAM so growisofs will use it
    > - growisofs -Z /dev/dvd /backups
    >
    > For some unknown reason, mke2fs /dev/dvd fails, or if it succeeds, it is
    > unreliable for writing. I may or may not get a complete cp /backups/*
    > /media/dvd but even if I do, I may not be able to mount it again. And
    > even if I can mount it again, there is no guarantee that subsequent cp's
    > will work.
    >
    > In short, working with DVD-RAM seems to be an exercise in frustration
    > even though it is the only game in town for doing repetitive backups.
    > It's supposed ability to be usable just like a hard disk is a myth, at
    > least until kernel 2.16.22.


    Never tried ext2. I do use some vfat formatted disks because Win98
    will not consistently recognize UDF DVD-RAM disks (it does recognize
    DVD-ROM's however). Never had any problems except that vfat on DVD is
    slow, of course vfat is slow on a large HD too.
    Could you be having some incompatablity problems with the DVD drive
    itself? Ext2 should work, and modern drives are supposed to handle bad
    sectors internally.

    Jerry

  9. Re: backup to DVD-RAM

    Jerry Peters wrote:
    > Gary Dale wrote:
    >> Gary Dale wrote:
    >>> Jerry Peters wrote:
    >>>
    >>>> I've never had any problems, other than DVD-RAM tends to be slow and a
    >>>> large amount of buffered writes tend to build up (fixed by mounting
    >>>> with the sync option).
    >>>>
    >>>> What's the "trouble" with working with UDF? My DVD-RAM mounts on
    >>>> /dev/sr0 in rw mode and I copy data to it, just as if it were a large
    >>>> floppy. That's the advantage of DVD-RAM over the other DVD whatevers,
    >>>> it behaves like a large floppy, no special formatting required.
    >>>>
    >>>> If you really must use growisofs, get the source and change it to your
    >>>> needs then.
    >>>>
    >>> I actually just tried using UDF directly and I found what the problem
    >>> is.
    >>>
    >>> It appears that there is a bug in UDF support that isn't fixed until
    >>> 2.6.22 (this is from the Wikipedia -
    >>> http://en.wikipedia.org/wiki/Universal_Disk_Format) that limits you to
    >>> file sizes of no more than 1G. I tarred and zipped the files before
    >>> backing them up to save space (even then the tarball is almost 3G), so
    >>> my backups failed.
    >>>
    >>> Still, the growisofs problem of wanting a clean disk bugged me, so I've
    >>> switched over to ext2 for now. I test for a file system by trying to
    >>> mount it as ext2. If it fails, I format it then mount it.
    >>>
    >>> Of course, this is not the file system anyone expects on a DVD-RAM disk,
    >>> so I will give UDF a try again when Debian/lenny becomes the new stable
    >>> release in a couple of years.

    >> I'm back to about the only method that seems to be reliable.
    >> - mkudffs /dev/dvd -- to blank the DVD-RAM so growisofs will use it
    >> - growisofs -Z /dev/dvd /backups
    >>
    >> For some unknown reason, mke2fs /dev/dvd fails, or if it succeeds, it is
    >> unreliable for writing. I may or may not get a complete cp /backups/*
    >> /media/dvd but even if I do, I may not be able to mount it again. And
    >> even if I can mount it again, there is no guarantee that subsequent cp's
    >> will work.
    >>
    >> In short, working with DVD-RAM seems to be an exercise in frustration
    >> even though it is the only game in town for doing repetitive backups.
    >> It's supposed ability to be usable just like a hard disk is a myth, at
    >> least until kernel 2.16.22.

    >
    > Never tried ext2. I do use some vfat formatted disks because Win98
    > will not consistently recognize UDF DVD-RAM disks (it does recognize
    > DVD-ROM's however). Never had any problems except that vfat on DVD is
    > slow, of course vfat is slow on a large HD too.
    > Could you be having some incompatablity problems with the DVD drive
    > itself? Ext2 should work, and modern drives are supposed to handle bad
    > sectors internally.
    >
    > Jerry


    I thought perhaps the issue was one of having to do an eject between
    operations but my testing gave me similar results with or without an
    eject. The main difference is that sometimes it takes two mounts after
    an eject - I guess mount times out a bit too fast. This makes testing
    for a successful mount a little trickier.

    I'm going to stick with growisofs for now, unless it starts giving me
    headaches. If it does, I'll try vfat.

    Thanks.

  10. Re: backup to DVD-RAM

    Gary Dale wrote:
    > Jerry Peters wrote:
    >> Gary Dale wrote:
    >>> Gary Dale wrote:
    >>>> Jerry Peters wrote:
    >>>>
    >>>>> I've never had any problems, other than DVD-RAM tends to be slow and a
    >>>>> large amount of buffered writes tend to build up (fixed by mounting
    >>>>> with the sync option).
    >>>>>
    >>>>> What's the "trouble" with working with UDF? My DVD-RAM mounts on
    >>>>> /dev/sr0 in rw mode and I copy data to it, just as if it were a large
    >>>>> floppy. That's the advantage of DVD-RAM over the other DVD whatevers,
    >>>>> it behaves like a large floppy, no special formatting required.
    >>>>>
    >>>>> If you really must use growisofs, get the source and change it to your
    >>>>> needs then.
    >>>>>
    >>>> I actually just tried using UDF directly and I found what the problem
    >>>> is.
    >>>>
    >>>> It appears that there is a bug in UDF support that isn't fixed until
    >>>> 2.6.22 (this is from the Wikipedia -
    >>>> http://en.wikipedia.org/wiki/Universal_Disk_Format) that limits you to
    >>>> file sizes of no more than 1G. I tarred and zipped the files before
    >>>> backing them up to save space (even then the tarball is almost 3G), so
    >>>> my backups failed.
    >>>>
    >>>> Still, the growisofs problem of wanting a clean disk bugged me, so I've
    >>>> switched over to ext2 for now. I test for a file system by trying to
    >>>> mount it as ext2. If it fails, I format it then mount it.
    >>>>
    >>>> Of course, this is not the file system anyone expects on a DVD-RAM disk,
    >>>> so I will give UDF a try again when Debian/lenny becomes the new stable
    >>>> release in a couple of years.
    >>> I'm back to about the only method that seems to be reliable.
    >>> - mkudffs /dev/dvd -- to blank the DVD-RAM so growisofs will use it
    >>> - growisofs -Z /dev/dvd /backups
    >>>
    >>> For some unknown reason, mke2fs /dev/dvd fails, or if it succeeds, it is
    >>> unreliable for writing. I may or may not get a complete cp /backups/*
    >>> /media/dvd but even if I do, I may not be able to mount it again. And
    >>> even if I can mount it again, there is no guarantee that subsequent cp's
    >>> will work.
    >>>
    >>> In short, working with DVD-RAM seems to be an exercise in frustration
    >>> even though it is the only game in town for doing repetitive backups.
    >>> It's supposed ability to be usable just like a hard disk is a myth, at
    >>> least until kernel 2.16.22.

    >>
    >> Never tried ext2. I do use some vfat formatted disks because Win98
    >> will not consistently recognize UDF DVD-RAM disks (it does recognize
    >> DVD-ROM's however). Never had any problems except that vfat on DVD is
    >> slow, of course vfat is slow on a large HD too.
    >> Could you be having some incompatablity problems with the DVD drive
    >> itself? Ext2 should work, and modern drives are supposed to handle bad
    >> sectors internally.
    >>
    >> Jerry

    >
    > I thought perhaps the issue was one of having to do an eject between
    > operations but my testing gave me similar results with or without an
    > eject. The main difference is that sometimes it takes two mounts after
    > an eject - I guess mount times out a bit too fast. This makes testing
    > for a successful mount a little trickier.
    >
    > I'm going to stick with growisofs for now, unless it starts giving me
    > headaches. If it does, I'll try vfat.
    >
    > Thanks.


    I have 2 different DVD drives, one's a Matsu****a and the other is an
    LG. I have a number of DVD-RAMS that the Matsu****a has trouble
    recognizing (the light blinks seemingly forever) while the LG drive
    recognizes them without any long delays. I had considered these disks
    as defective until trying them in the LG.

    Jerry

  11. Re: backup to DVD-RAM

    Jerry Peters wrote:
    > Gary Dale wrote:
    >> Jerry Peters wrote:
    >>> Gary Dale wrote:
    >>>> Gary Dale wrote:
    >>>>> Jerry Peters wrote:
    >>>>>
    >>>>>> I've never had any problems, other than DVD-RAM tends to be slow and a
    >>>>>> large amount of buffered writes tend to build up (fixed by mounting
    >>>>>> with the sync option).
    >>>>>>
    >>>>>> What's the "trouble" with working with UDF? My DVD-RAM mounts on
    >>>>>> /dev/sr0 in rw mode and I copy data to it, just as if it were a large
    >>>>>> floppy. That's the advantage of DVD-RAM over the other DVD whatevers,
    >>>>>> it behaves like a large floppy, no special formatting required.
    >>>>>>
    >>>>>> If you really must use growisofs, get the source and change it to your
    >>>>>> needs then.
    >>>>>>
    >>>>> I actually just tried using UDF directly and I found what the problem
    >>>>> is.
    >>>>>
    >>>>> It appears that there is a bug in UDF support that isn't fixed until
    >>>>> 2.6.22 (this is from the Wikipedia -
    >>>>> http://en.wikipedia.org/wiki/Universal_Disk_Format) that limits you to
    >>>>> file sizes of no more than 1G. I tarred and zipped the files before
    >>>>> backing them up to save space (even then the tarball is almost 3G), so
    >>>>> my backups failed.
    >>>>>
    >>>>> Still, the growisofs problem of wanting a clean disk bugged me, so I've
    >>>>> switched over to ext2 for now. I test for a file system by trying to
    >>>>> mount it as ext2. If it fails, I format it then mount it.
    >>>>>
    >>>>> Of course, this is not the file system anyone expects on a DVD-RAM disk,
    >>>>> so I will give UDF a try again when Debian/lenny becomes the new stable
    >>>>> release in a couple of years.
    >>>> I'm back to about the only method that seems to be reliable.
    >>>> - mkudffs /dev/dvd -- to blank the DVD-RAM so growisofs will use it
    >>>> - growisofs -Z /dev/dvd /backups
    >>>>
    >>>> For some unknown reason, mke2fs /dev/dvd fails, or if it succeeds, it is
    >>>> unreliable for writing. I may or may not get a complete cp /backups/*
    >>>> /media/dvd but even if I do, I may not be able to mount it again. And
    >>>> even if I can mount it again, there is no guarantee that subsequent cp's
    >>>> will work.
    >>>>
    >>>> In short, working with DVD-RAM seems to be an exercise in frustration
    >>>> even though it is the only game in town for doing repetitive backups.
    >>>> It's supposed ability to be usable just like a hard disk is a myth, at
    >>>> least until kernel 2.16.22.
    >>> Never tried ext2. I do use some vfat formatted disks because Win98
    >>> will not consistently recognize UDF DVD-RAM disks (it does recognize
    >>> DVD-ROM's however). Never had any problems except that vfat on DVD is
    >>> slow, of course vfat is slow on a large HD too.
    >>> Could you be having some incompatablity problems with the DVD drive
    >>> itself? Ext2 should work, and modern drives are supposed to handle bad
    >>> sectors internally.
    >>>
    >>> Jerry

    >> I thought perhaps the issue was one of having to do an eject between
    >> operations but my testing gave me similar results with or without an
    >> eject. The main difference is that sometimes it takes two mounts after
    >> an eject - I guess mount times out a bit too fast. This makes testing
    >> for a successful mount a little trickier.
    >>
    >> I'm going to stick with growisofs for now, unless it starts giving me
    >> headaches. If it does, I'll try vfat.
    >>
    >> Thanks.

    >
    > I have 2 different DVD drives, one's a Matsu****a and the other is an
    > LG. I have a number of DVD-RAMS that the Matsu****a has trouble
    > recognizing (the light blinks seemingly forever) while the LG drive
    > recognizes them without any long delays. I had considered these disks
    > as defective until trying them in the LG.
    >
    > Jerry


    I insist on LG drives. I've found them to be reliable. Other drives that
    I've had have all developed problems fairly quickly. Plus, LG has had
    DVD-RAM support for a long time, while other drives frequently don't.

    In this case, it is an LG drive that is giving me the problems. I may
    have a disk gone bad because I can't currently get it formatted with any
    file system I try. On the other hand, I may need to replace the drive.
    I'm going to have go to the site and try the disk in a different drive.
    There may be more than one bad disk, which would indicate a drive problem.

  12. Re: backup to DVD-RAM

    Hopefully the final word on the topic:
    I've been having good luck with the following approach:
    - create a bzipped tar of the /home directory
    - use split to split it into 1G files to get around the UDF support bug
    - try to mount the DVD-RAM as UDF. If it fails, format it then mount it
    - cp the split files to the DVD-RAM, comparing after copying. If the
    copy didn't work, retry it once only.

    So far things seem to be working out. I'm getting an error on some
    copies but so far just on one of the split files, and recopying that
    file has always worked so far. Last night's backup was clean on the
    first try.

    I'm not thrilled with this approach because it is overly complicated.
    However, it has been working reliably so far, and that is the main criteria.

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