Red Hat ENTERPRISE LINUX 4 - INTRODUCTION TO SYSTEM ADMINISTRATION Administration Manual page 187

Chapter 8. Planning for Disaster
There are many other options to
man pages.
find(1)
8.4.2.3. /
dump restore
The and
dump restore
As such, many system administrators with UNIX experience may feel that
viable candidates for a good backup program under Red Hat Enterprise Linux. However, one method
of using can cause problems. Here is Linus Torvald's comment on the subject:
dump
From: Linus Torvalds
To: Neil Conway
Subject: Re: [PATCH] SMP race in ext2 - metadata corruption.
Date: Fri, 27 Apr 2001 09:59:46 -0700 (PDT)
Cc: Kernel Mailing List
[ linux-kernel added back as a cc ]
On Fri, 27 Apr 2001, Neil Conway wrote:
I'm surprised that dump is deprecated (by you at least ;-)).
> >
use instead for backups on machines that can't umount disks regularly?
>
Note that dump simply won't work reliably at all even in 2.4.x: the buffer
cache and the page cache (where all the actual data is) are not
coherent. This is only going to get even worse in 2.5.x, when the
directories are moved into the page cache as well.
So anybody who depends on "dump" getting backups right is already playing
Russian roulette with their backups.
right results - you may end up having stale data in the buffer cache that
ends up being "backed up".
Dump was a stupid program in the first place. Leave it behind.
I've always thought "tar" was a bit undesirable (updates atimes or
>
ctimes for example).
>
Right now, the cpio/tar/xxx solutions are definitely the best ones, and
will work on multiple filesystems (another limitation of "dump"). Whatever
problems they have, they are still better than the _guaranteed_(*)
corruptions of "dump".
However, it may be that in the long run it would be advantageous to have a
"filesystem maintenance interface" for doing things like backups and
defragmentation..
Linus
(*) Dump may work fine for you a thousand times. But it _will_ fail under
the right circumstances. And there is nothing you can do about it.
Given this problem, the use of
ever, was originally designed to backup unmounted file systems; therefore, in situations where
dump
it is possible to take a file system offline with
(and
cpio find
: Not Recommended for Mounted File Systems!
programs are Linux equivalents to the UNIX programs of the same name.
linux-kernel At vger Dot kernel Dot org
<
It's not at all guaranteed to get the
/
dump restore
umount
); to learn more about them read the
on mounted file systems is strongly discouraged. How-
, remains a viable backup technology.
dump
175
and
cpio(1)
and
dump restore
>
What to
data
are