I have been using a rev drive atapi mounted in my sme server 7 final
I have been backing up to this with Darrel Mays backup2 contrib
rev drive shows up on /etc/fstab as
//dev/hdd /media/cdrom auto pamconsole, exec, noauto, $
In the backup2 contrib it is mounted as
/media/cdrom
Works well you can mount it with
mount /media/cdrom
and delete files or add them no problems with mc or winscp
Haven't tried the new DAR backup system yet as it looks as though you would have to format each disk to ext3