If you wanna spend some $$ you can get SyncSort Backup Express which has a bare metal restore option (for additional $$) or any other decent DR solution. The online backup of a running system needs to be done properly or the restored image may give you more problems.
Using the tools at hand, LVM snapshots may go a long way. I've never tried but I'm kinda curious. Maybe when I get some time I'll try it out for myself.
As always, throughly test any solutions you want to pursue.