[wplug] Q: how to make image copy of disc to CD/DVD?

[Jonathan S Billings]

Vanco, Don wrote:
>>dd if=/dev/hda of=somefile.img
> 
> (snip)
> 	I didn't mention this because I cannot remember the required
> syntax, but there are decidedly portions of the system you want to skip
> - like /proc, other "live" components, etc.  

Actually, /proc is not a filesystem on a real disk,  However, you are 
right that it'll capture a running OS in a live state.  Services might 
not start up correctly from a recovered disk, databases might be caught 
in mid-write, etc.

Also, writing a 'dd' image to the same disk you are imaging will *never* 
work unless you are also compressing on the fly because the image size 
will be bigger than the filesystem, and even then, the image will 
contain a partial image of the image you are writing.

'dd' isn't the best backup tool, since it copies every bit on the disk, 
regardless of whether the filesystem is using it or not.  If you want to 
get a copy of the *filesystem*, I suggest using the corresponding dump 
program.  You could copy the dump files to a CD/DVD image, or simply use 
the 'restore' program to make a copy of the filesystem on the image.

If you don't have a dump program for your filesystem, you could also use 
tar, rsync, pax, cpio, etc.  There are piles of open source tools that 
were written for this purpose but I think it's best to stick to the 
well-known tools that'll be around on nearly any unix/linux system, like 
the ones I've mentioned.


-- 
Jonathan S. Billings <billings at negate.org>