Couriousous, one of the MDV contributors, has written an interesting parallel boot system for MDV which is much less radical than other similar systems. It needs a bit of manual patching of initscripts and so forth in its current pre-alpha state, but I had some spare time so I thought I'd give it a go. The results are interesting - it works perfectly but only saves me 4 seconds, indicating that current startup is already pretty well optimized. The resulting bootchart (below) is almost completely I/O bound, and the only downtime is I think while it's waiting to see if I'll press 'I' for interactive boot. Interesting stuff. 42 secs isn't a bad startup time for a full desktop system with email and web server thrown in for good measure!