I do these backups in a very simple fashion: by running a script on Dom2 start (and on hosting too - for SP).
Here's the script: save_script.awk
Code:
BEGIN {
	timestamp_file = "Last-total-save-timestamp.txt";
	t = systime();
	stamp = strftime("%Y%m%d-%H%M%S",t);
	stamp2 = strftime("%Y-%m-%d",t);
	saveAll = 1;
	if ((getline Last_stamp < timestamp_file) > 0)
	{
		if (stamp2 == Last_stamp)
			saveAll = 0;
	}
	close(timestamp_file);
	if (saveAll)
	{
		cmd = sprintf("zip -r save-all-%s * -i@save.lst",stamp);
		print stamp2 > timestamp_file;
	}
	else
		cmd = sprintf("zip -r -t %s save-%s * -i@save.lst",Last_stamp,stamp);
	system(cmd);
}
You'd need to insert 
gawk -f save_script.awk into your Dom2 startup
And you'll need save.lst:
Code:
*/ftherlnd
*/*.2h
*/*.trn
That's the only Dom2-specific file.