UPS recommendations

[Dan Christensen]

We're in the planning stages for preparing a room to house a small
cluster, consisting of roughly 8 to 10 dual-cpu nodes to begin with.
We are planning to use two or three 20A 120V circuits.  (Two should be
enough, but three will give us room for future expansion.)

We are wondering what kind of UPS to get.  Is it standard to get
one UPS per circuit, or are there affordable UPS units that will
manage several circuits?  ("Affordable" is a key word.)  Most outages
are short, so we just need between 30 and 60 minutes of battery
backup.  Also, I've heard that some UPS's can monitor the room
temperature and shut down the machines if it gets too hot.  This
would be useful.

So, any advice about what we should get?  

I'm also curious about monitoring the UPS's.  If there are several
of them, does one usually monitor all of them using the head node,
or split this task up?

Thanks,

Dan

-- 
Dan Christensen
jdc at uwo.ca