(On Ubuntu 11.10 - configuration inherited from 10.10)
Occasionally the boot process seems to suffer a race condition where a starting process misses some of the Raid-1 FSes, build via mdadm.
Looking at the start script, runlevel 5, (3 is similar anyway)
K00ntop S15bind9 S16openvpn S20kerneloops S20nfs-kernel-server S20nginx S20php5-fpm S20postfix S20speech-dispatcher S20winbind S20xinetd S23ntp S25bluetooth S25mdadm ...
There a bunch of processes started before mdadm, and nginx has some of web data on a MD array. While it's unlikely someone accesses the server at this very time, I wonder if it could be the reason.
Actually, I'm a bit surprised mdadm to be started that late in the boot process.
Is it not/recommended to run it earlier, say S10?