Words

Racks :

-noun

1. a framework of bars, wires, or pegs on which articles are arranged or deposited: a clothes rack; a luggage rack.

2. a fixture containing several tiered shelves, often affixed to a wall: a book rack; a spice rack.

http://dictionary.reference.com/browse/+racks+

Until :

-Conjunction

1. up to the time that or when; till: He read until his guests arrived.

2. before (usually used in negative constructions): They did not come until the meeting was half over.

http://dictionary.reference.com/browse/until

Datacenters:

–noun

1. A facility equipped with or connected to one or more computers, used for processing or transmitting data.

http://dictionary.reference.com/browse/datacenter