backing up /sys

[Alexey Fadyushin]

Bob McClure Jr wrote:

>I'm in the process of checking out a CD/DVD-based backup package.
>
>http://www.bluehaze.com.au/unix/cdbkup.html
>
>In my first test, I noticed in the error log a bunch of carps about
>file sizes changing in /sys.  I know that /proc is a pseudo filesystem
>comprising nothing but hooks into the kernel, and I know that I don't
>want to back that up.  /sys looks like the same sort of thing, full of
>directories that take up 0 bytes, down to files that ls reports as
>4096 bytes.
>
>Is it safe to assume I don't want to backup /sys?
>
>Cheers,
>  
>
/sys is a mount point for sysfs filesystem. Sysfs is a virtual 
filesystem similar to procfs in 2.6 line of Linux kernels.
 From the kerlnel documentation (menuconfig help):

The sysfs filesystem is a virtual filesystem that the kernel uses to
export internal kernel objects, their attributes, and their
relationships to one another.

Therefore, you do not need to backup it, the filesystem and its content 
will be recreated by kernel when mounted.

Alexey Fadyushin.
Brainbench MVP for Linux
http://www.brainbench.com