topic Re: tar cvf proc.tar /proc in Operating System - Linux

tar cvf proc.tar /proc

Jung.S.H — Wed, 19 Jul 2006 07:49:53 GMT

OS : RedHat Linux (Kernel 2.4)
model : HP
I run command "tar cvf proc.tar /proc"
Then system is rebooting ...
what is the problem?
I have no idea.

How do I find out the cause for the rebooting?

Tell me the reason Why reboot the system?

Re: tar cvf proc.tar /proc

Ivan Ferreira — Wed, 19 Jul 2006 09:02:20 GMT

Check your /var/log/messages files for some clue. You don't need to backup the /proc file system, anyway, I think that the system shouldn't reboot if you try to do that, you only should get errors.

Re: tar cvf proc.tar /proc

Vitaly Karasik_1 — Wed, 19 Jul 2006 09:27:38 GMT

can you reproduce this problem?
agree with Ivan - this tar command shouldn't cause crash/reboot.

Re: tar cvf proc.tar /proc

Uwe Zessin — Wed, 19 Jul 2006 11:50:55 GMT

I don't have an RH system to look at, but on a SuSe Professional, the /proc tree includes a mapping to memory (/proc/kcore), so your TAR file might get larger that you expect...

Re: tar cvf proc.tar /proc

Ivan Ferreira — Wed, 19 Jul 2006 12:27:57 GMT

I just tried the tar and it ends with errors, the system should not crash, but I agree that there are some files, like the kcore that are very large.

Does the system always crash?

Re: tar cvf proc.tar /proc

Matti_Kurkela — Fri, 21 Jul 2006 11:24:29 GMT

I seem to recall that this was a known bug, fixed at some point of the 2.4 kernel series.

If you're using some version of RedHat Enterprise Linux, are you up to date on patches? If you use a RedHat 7.3 or 9, consider applying the patches created by the Fedora Legacy project:
http://www.fedoralegacy.org/

Re: tar cvf proc.tar /proc

Jung.S.H — Sun, 23 Jul 2006 18:59:06 GMT

I have heard that /proc filesystem must not tar command from hp engineear.
Because /proc filesytem is virtual file-system.
"# tar â cvf /tmp/proc_backup /proc "
command cause system deadlock

Re: tar cvf proc.tar /proc

Vitaly Karasik_1 — Mon, 24 Jul 2006 01:13:10 GMT

AFAIK :
even /proc is virtual FS and we don't need to backup it (except for snapshoot linux box state), there is no problem to tar /proc FS. And, of course, linux doesn't crash during /proc taring.

And I run tar for /proc a few times right now without problems.

Re: tar cvf proc.tar /proc

George Liu_4 — Tue, 25 Jul 2006 15:54:58 GMT

Problem seems in the function/library calls when you run tar on /proc directory. Some function/library call could trigger the kernel panic/reboot. You shouldn't be surprised.
You won't be surprised if the system reboot after you type in
echo r >/proc/sysrq-trigger