"Relax and Recover" (rear) is a useful tool, written specifically in the bash dialect, that will write a compressed clone of your system to a bootable USB flash drive, network share (NFS/SMB), and other targets.

Booting with rear, a (somewhat "klunky") interface will allow you to restore your captured backup, apparently pristine.

It is similar in effect to the HP-UX Ignite tool that I used on that platform.

Oracle has published a number of articles and blogs on or relating to it, and it is well worth study. The invocation of tar that preserves the SELinux contexts is particularly worth capturing.