new to alpha -- having trouble booting new centos install from ha rd-drive following install on ES40

[Scott Pendergast]

Hi we've recently inherited some ES40's DS20's and a bunch of DS10L Alpha
boxes we'd like to run Centos 4.x on and all goes well until the reboot
following the install.

I've tried halting at SRM and trying to explicitly boot from the hd but keep
getting errors indicating no valid boot block is found on the target drive.
>From what I've read I suspect it is something to do with aboot, etc.  I'm
new to the Alpha, so don't know if the boot track should have to be manually
written to the drive after install, if the installer is supposed to take
care of that for you, etc.  I've tried various partitioning schemes, etc and
the aboot.conf changes acordingly so it would appear that the installer is
taking care of aboot but I can't be sure.

These boxes were previously TRU64 boxes (running fdisk /dev/sda reports a
BSD disklable, etc in case that helps, or hurts, in my case)

Any insight would be much appreciated!

Thanks,

Scott