[BBLISA] Good way to recover Linux server

[snagao]

I am looking for a good way to recover a RHEL ES3 server - especially in a DR scenario.  For my AIX servers, I use the mksysb utility to make a bootable image of the OS. 
 
I know Linux doesn't have anything equivalent to AIX's mksysb command, but can someone please recommend a tool or method for me to back up the OS and recover it quickly for DR testing?
 
My thanks in advance to all those who respond.
 
 
- sharon