[Beowulf] powering up 18 motherboards

[David Mathog]

>I was really hoping a decent $200-300 UPS would come to
> the rescue here. Oh well.

APC makes Power Distribution Units that can be set to 
start loads at fixed intervals.  If you had access to a
208V/3 phase line the AP7990 costs about $650, uses that
as input, and outputs 24 120V sockets.  They make quite
a few of these PDUs in different configurations
so maybe you can find one that does what you want?

Another, much cheaper option, would be to set the slave
node BIOS to use "Wake on LAN" (if it works on your systems)
and NOT to start on power up.  Then when power came up the
headnode would boot and the others would just warm up
enough to listen to their ethernet cards.  I don't
expect that the start up current going to that mostly off 
state would be very high, even for 18 computers, since neither
the disks nor fans start spinning. Once the head node
comes up you can boot the slaves using etherwake.

Regards,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech