[CentOS] backup with dd

Les Mikesell wrote:
> Clonezilla-live is a boot-from CD linux that will copy just the used 
> portions of the disk and can save to another disk or image files on 
> local disks or over the network.  I'd recommend it over dd, but maybe 
> someone has a way to do LVM snapshots so the copy can be done without 
> a reboot.
>

i've generally used dump(8) and restore(8) to image ext2/3FS....       
this can even be used to do an incremental dump although I rarely do that.

while i've never tried this, in theory, if you're using LVM, you can 
snapshot a live filesystem, then dump the unmounted snapshot to get a 
clean image.   

note that snapshotting a database is a somewhat dicey proposition, 
however.    I generally prefer to use the databases own dump facility 
rather than backing up its raw tablespace files (pg_dumpall for 
postgres, etc).