I like the title of Brandon Robinsons talk for debconf5 so much I’ve stolen it for the title of this blog! wtfm = Write The Freakin Manual
Speaking of which I added a description of the union* cheatcodes on Kanotix (and fromiso) to the Kanotix Wiki StartParameters. Short description, unionro and unionrw allow you to use any directory/partition/loopback file as a read-only or read-write layer on top of the cd. This allows persistence with unionfs, a really easy way to “remaster” a cd, perhaps to a dvd.
I have also been hacking on trying to use Fabian Franz’s sarge-unionfs as a basis for an file image which you boot (initrd mounts it), makes all changes in a unionfs snapshot, compress the unionfs snapshot on shutdown (to cloop/squashfs etc) and then on startup remount all compressed snapshots over the original system. At any stage backup and consolidation of snapshots can reduce disk space usage back down by bringing your system down to having a minimal amount of live duplication. I’d also hope to create a script for the snapshot so you could have a cron job create new snapshots while the system is running but I wonder if this will work out ok (can processes with open files for writing handle the underlying system switching to read-only).
Of course I got to a first basic test image (just adding the startup and shutdown code) and it fell over … why? Well I think it’s cause the kernel/initrd doesn’t support sata 
So it’s burn a cd or hook up Paul O’Malley’s 80G ide driver which I still haven’t given back to him since the RDS! Or maybe I can get it to run off my 256M usb key 