so, i have a couple of 5000's with two RZ25.  when booting after a
power cycle, i often get from the non-boot disk:

rz2: not ready

(i think that's the error; i don't have access to the console right
now).  this generally causes fsck to fail cuz it can't find the
partition on that disk, and then i type /sbin/reboot at the prompt,
and this time it works.  it seems as if the rz driver is not giving
the disk long enough to spin up?  it only happens when the drive is
not spun up before the boot begins.