[Techtalk] backup - tar

[Terri Oda]

On Aug 30, 2004, at 3:04 PM, Maria McKinley wrote:
> Hi there,
>
> I am using tar to backup, and I am really frustrated with it.  It 
> keeps going through a dozen or so files, and then quitting with no 
> explanation.  It does this no matter which files I try to backup.  The 
> command I use is:
>
> nohup tar -czvf /dev/nst0 --atime-preserve /home > /tmp/backup &

Other people have already explained how to see those ever-important 
error messages, so I won't repeat that, but I do have a guess as to the 
problem...

My guess is that it's running out of space somewhere along the line -- 
that's the time I've seen tar give up after a bunch of files.  Have you 
tried making a tarball elsewhere to see how big the end result is, or 
is that infeasible?

Also, I can't remember if gzipping is done as tar goes, or if it needs 
to wait 'till the end before it does the zipping... You might want to 
find out which it is, though, since if it's happening at the end, you 
might be able to make the tar elsewhere and then gzip to the tape 
drive, saving yourself the use of temporary space.   I have a feeling 
it zips as it goes, though, so that probably won't help.  Still, you 
might be able to eek out a bit more space using bzip2 instead of gzip 
(usually this is the j flag instead of the z one), if you need it.