[mdlug] Network backup options

[Raymond McLaughlin]

David Relson wrote:
> On Sun, 04 Feb 2007 08:25:17 -0500
>
> There are several entries in / that aren't directories,
> notably /dev /proc.  They don't need to be backed up.  To the degree
> that they reflect the running state of your system, they can't be
> backed up.  Don't worry about them!  Even better, use tar's "--exclude"
> option to ignore them.
> 

Begging to differ /dev contains special files that serve as pointers to
all of your hardware devices. It can be backed up. The real question is
whether or not it needs to be.

Depending on your distro you may or may not need to back this tree up.
On CentOS4.4, and by extension close Redhat derivatives, the dev tree is
emptied when the system powers down. On a Debian (installed by way of
knoppix) system it remains populated between power cycles, and so might
well need to have these special files present at boot. In either case,
if you back them up do so in a manner that backs up the special files,
not the devices that they point to. I determined the above information
by power cycling a dual boot system and looking in the respective directory.

Returning to the topic of file systems that reflect the running state of
a system, how about that /sys tree? I just noticed it a couple of months
ago and haven't had time to really look into it. It appears to be
somewhat like /proc but without being tied to specific process numbers.
I have heard that this is more BSD like than /proc, and that Linus has
been promoting it sinc the start of the 2.6 kernel. I observe that it
also remains populated on Debian (Knoppix) after power off. I didn't
think to check the CentOS while Deb was running and don't have time to
power cycle right now.

Can anyone more knowledgeable chime in with a quick summary of the /sys
tree?

Raymond McLaughlin