Re: [Bug-tar] problem (bug?) using listed-incremental on multiplefile-systems

[Wolfgang Denk]

Dear Sergey,

on Mon, 04 Oct 2004 15:26:37 +0300 you wrote:

> Niels Laukens <address@hidden> wrote:
> 
> > tar --create --one-file-system --preserve-permissions --label "Bla" \
> > --exclude="/some/file" --listed-incremental "listfile" \
> > /boot /usr /var /tmp / | bzip2 ...
> 
> --one-file-system option means 'do not dump any directories that are
> on filesystems other than the current one', i.e. mount point directories
> are added to the output archive, but their content is not. Consequently,

I - and probably others, too - would expect that

        tar --one-file-system ... dir1 dir2 ...

would put the same list of files into the tarball as printed  by  the
command

        find dir1 dir2 ... -xdev -print

I would ESPECIALLY expect that this behaviour does NOT depend on  the
use  of "--listed-incremental" - the bevahoour of tar regarding which
directories are scanned and archived should  change  between  a  full
dump and an incremental dump.

> when restoring from the incremental backup, tar assumes the directories
> where empty. This is what occurs with root/boot directory in your example.

I'm not sure which role restoring plays here. What I see is that some
files are not even put into the archive inthe first palce,  and  that
this  behavious  CHANGES depending if I use relative or absolute path
names.

> No, it is not. Using --one-file-system (and, generally speaking, any
> option abridging the set of files to be included in the archive) implies
> that these files will be lost when extracting from the resulting archives.

But this works perfectly fine when as long as I don't use incremental
dumps. So what's the difference?

> > or am I just not using the right commands?
> 
> Do not use --one-file-system when creating incremental archives.

And what is your recommendation  how  to  perform  regular  full  and
incremental  dumps  in  a hierarchy of mounted filesystems, where you
for example want to omit any (NFS) mounted subdirectories?

[I've just run into the same problem - see  my  previous  message  to
this list which includes a test case.]

Best regards,

Wolfgang Denk

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