I've been listening to the stuff about modifying rc.sysinit (which may
turn out to be useful) but of course that isn't the only place where the
raid stuff gets started.

This may all be obvious to everyone but just in case anyone doesn't
already know...

The code to perform raid autodetection is added to the initrd *iff* raid
sets are detected when mkinitrd is run (ie at kernel install/upgrade
time).  Similarly the raid (and relevant scsi etc) modules are only copied
if they are in use at the time.

Thus if one installs a system and later configures raidsets (or adds
hardware needing extra modules) they won't be autodetected on reboot.  If
you force the rebuilding of the initrd (or happen to do an update
perhaps), with the raid stuff in place, then all should work as expected.

If you don't want to mess with /sbin/mkinitrd they you can simply
re-install the existing kernel(s) or re-run the postinstall scriptlet to
force the initrd to be rebuilt (which runs /sbin/new-kernel-pkg and from
there mkinitrd).

-- 
Jon Peatfield,  Computer Officer,  DAMTP,  University of Cambridge
Mail:  [log in to unmask]     Web:  http://www.damtp.cam.ac.uk/