Need to recover a file from tape

[rankar]

Hi all, our servers are being backed up via tape using the tar -cvf command. What I need to know is how can I retreive a file from tape. I tried tar -xvf /dev/ht0 /etc/motd as a test but it would just hang, all suggestions would be helpful.
thanks,
rg

 

[pcunix]

Just hang as in it didn't run through the tape or hang as in did nothing useful?

Try "tar tvf /dev/ht0 | more"

If that lists files, note how they are listed- if for example, they begin ./, you may need to do

tar -xvf /dev/ht0 ./etc/motd

Or if they list as //, then

tar -xvf /dev/ht0 //etc/motd

would be what you want (though I din't think Linux tar had these problems- those are typical of regular old Unix tar's behaviour).

Or, it may just be that /etc/motd is not on the tape even though you think it should be- if that's the case, tar will keep on reading until it hits eot, which might look like "hung" on a big backup.


But if you mean hang as in really doing nothing, are yu sure this device is working?


Tony Lawrence
SCO Unix/Linux Resources

http://pcunix.com

tony@pcunix.com

 

[rankar]

This is the output from tar tvf /dev/ht0 -rw-r--r-- root/root 2147483647 2001-12-27 00:21:02 backup.tar

So it looks like all the filsystems being backed up are in this backup.tar file. Now if I wanted to get just one file from this file, would
tar xvf /dev/ht0 /backup.tar/etc/motd work?

 

[ifincham]

Hi,

Yes 'tar xvf /dev/ht0 /backup.tar/etc/motd' should extract the single file /etc/motd from the /backup.tar archive on /dev/ht0. I.e. you use the full path to the file within the archive not just the archive name.

Regards

 

[rankar]

Thanks for all your help!

 

[pcunix]

Looks to me like you would need to do something like this:

cat /tmp
tar xvf /dev/ht0 backup.tar
# now see what's in backup.tar
tar tvf backup.tar
cd /
tar xvf /tmp/backup.tar etc/motd

# or- safer -
cd /tmp
tar xvf backup.tar etc/motd
cd /tmp/etc
cat motd
# if it's what you want..

cp motd /etc/motd



Tony Lawrence
SCO Unix/Linux Resources

http://pcunix.com

tony@pcunix.com