I've taken the info from the built in backup, expanded upon it, & built it into 2 scripts, one for SMB backup to a LAN workstation & one to backup to a USB drive plugged into the SME itself; I've used them with backup files up to approx 80GB without issue (prob 150GB+ raw files), mind you the servers tend to be pretty capable multicore with at least 8GB ram & ssd storage.
These are tailored to suit me & my system(s) but are easily modded to suit another; I currently have them running as a scheduled task on 4 servers.
The scripts assume that the local drive has enough space to create the tgz backup file so if the drive is really full they won't work. I use a tgz file to allow me to backup all file perms that would otherwise be lost if natively backing up files to a Windows share.
I also use Lazy Admin Tools (
https://wiki.koozali.org/Lazy_Admin_Tools) 'lat-dump -d' to take a snapshot of the core setup, again for primarily for reference only, but somtimes to reconfigure the new server using 'lat-restore -a'.
The scripts backup the following:
/root
/etc/e-smith/templates
/etc/e-smith/templates-user
/etc/e-smith/templates-custom
/etc/e-smith/templates-user-custom
/etc/ssh
/etc/sudoers
/etc/passwd
/etc/shadow
/etc/group
/etc/gshadow
/etc/samba/secrets.tdb
/etc/samba/smbpasswd
/home/e-smith
Note: I always restore files manually or use them as a reference instead of restoring, particularly files belonging to yum or rpm based contribs.
I can sanitize these scripts & post if you think they may be of use.