There is a cron job running on a machine on our office network. It was set up by somebody else. The script run by the cron backs up a samaba share onto tape. The job is definitely running, because if I run the backup manually, I can see the tar command's output and the drive comes alive and starts doing stuff....

The cron just runs the simple command:

tar cv /export/share >/dev/st0

but how would I access the contents of /dev/st0 if I had to recover one of these backups?

the 'ls' and 'file' commands tell me the following :

root@lon-fs-1:~# ls -al /dev/st0
crw-r----- 1 root disk 9, 0 Jul 18 1994 /dev/st0
root@lon-fs-1:~# file /dev/st0
/dev/st0: character special (9/0)

I don't know what a 'character special' file is, and it looks rather small to me. The timestamp is really old too. What is all this about?

christo

Pretty much anything in /dev is going to be a special file. Unix/Linux treats everything as a file. Drivers, directories, everything (simplified speak, don't attack me folks. :_) ) is a file.


Here are some example "put on tape" / "take off of tape" commands, edited for your setup.


To back up your /etc and your /home directories:

tar cvf /dev/st0 /etc /home



To extract a backup you'd use 'x' rather than 'c':


tar xvf /dev/st0

OR to only pull back certain files:


tar xvf /dev/st0 <file(s)>



Keep in mind that whatever directory you are in is where it will put the files. So if you don't want to restore /etc over your current one, for example, you'd make sure to be in a /tmp directory...

This is just an example, and I hope it was helpful. If you need more assistance, just shout!