Something strange happened to me attempting to put the root filesystem of a lenny installation on PE1650 on an LVM volume. I don't know whether or not this affects all PE1650s, are just the ones with a particular RAID controller. The machine I was installing (DYSPROSIUM) apparently uses the aacraid driver (percraid, with kernel, bios, and monitor version 2.7).
The problem is that there is not enough synchronization in the initramfs. For some reason, the SCSI sd driver takes a long time to attach to the defined RAID volumes. The initramfs scripts don't wait for that, or don't know about the problem, and attempt to activate the LVM volumes before the RAID volume backing the LVM volume group is attached. As a result, it can't find the root filesystem, since getting the LVM volume requires the "lvchange -ay <volume>" command, and the loop waiting for root to be ready is just looking for the device to appear.
To work around this problem, I added an extra sleep to the lvm scripts in the initramfs. I will add a patch, and appropriate dpkg-divert invocations later tonight.
-- kbare@CLUB.CC.CMU.EDU 2009-09-26 21:10:24