What is the industry standard for the amount of power provided for a
42u rack at a typical datacenter? 20 amps, 60 amps?  Is power
typically redundant at the point it enters the rack or do customers
typically have to purchase redundant power in order to be assured 100%
uptime?  If typical power provided is 20 ams, what is the typical cost
to upgrade to 30 ams or more?  Do datacenters use power as a way to up
an othewise low monthly rack fee?  In one of our datacenters, our rack
appearently comes with a 20 amp power connection (which doesn't seem
to be enough to support even 1/2 of the computers we plan to put into
the rack) and they want an additional $150 per month to upgrade to 30
ams, is all of this within normal industry standards?

Dear legalspan,

20 amps is indeed typical for a 42u rack. Although this is not enough
for a maxed-out rack, it suffices for many data-center customers. A
power upgrade will usually cost $25 to $50 per month for each
additional 20 amps, so I do have to question the $150 upgrade your
data center is asking.

On the other hand, you may be overestimating the amount of power you
really need. Bear in mind that you won't be able to stuff anywhere
near 42 servers into a 42u rack. After subtracting the unusable bottom
slot and the space needed for switching, routing, cooling,
administration, and spares, you'll most likely end up with 25 to 35
server units in the rack. When you consider that your modern 1u server
draws about 0.75 amp during normal operation, 30 amps should suffice
for up to 40 servers. The only time a server draws anywhere near its
maximum power rating is during bootup, so you'll want to make sure any
mass booting is staggered such that no more than a quarter of your
machines are starting up at any one time.

Your data center should take care of all power backup needs to ensure
an uninterrupted supply of juice at all times. If an outfit expects
you to haul in your own UPS units, it's evidence that you're dealing
with a corner-cutting operation that probably isn't worthy of your
business.

Executive summary: 20 amps normal, $150/month for a 10 amp upgrade not
normal. Redundant power is normal and expected. It doesn't surprise me
that a data center would bait-and-switch by jacking up the basic price
with costly upgrades, nor should it surprise them when you take your
business elsewhere. If I were in your shoes, I would definitely seek
quotes from other data centers in the neighborhood.

Regards,

leapinglizard