[rescue] Deciding how to place machines in a rack...

[Earl Baugh]

I'm to the point where I'm starting to assemble my new rack, and placing
machines in it... but I've got some questions regarding how to space them.

I've got a 420R, 220R, a Lightspeed KVM (think that's the name) for 5 Sun
monitors, 4 rack mount PCs (1 1U, and 3 4U)  a shelf for some
switches and a DSL router, and a shelf for 2 Sparc 10's.    The old rack was
just an open 4 post system (actually 2 2-post systems mounted to a common
base
with no sides or back).   The new rack has side panels, nice cable guides on
the sides, a front and back door, and a top.   I installed 2 2-fan
assemblies on to the
top this weekend.   It's a full 3 foot+ deep rack (I don't have the actual
distance, it's 39-40 or some such deep... the 420 and 220 will fit in with
the doors closed, with
cables installed, if the experience with the 420 is any indicator.

I was thinking the 420R and 220R on the bottom.  I've got them I think, a
"tad" too high in the old rack... didn't quite get killed putting them in,
and while it IS handy to have
them slide out on their rails at waist height or higher (no bending to put
stuff in them), I am thinking for safety, it's better to put them in the
bottom.

The FEH says I need 63% or some such air intake.. they say leave front and
back doors off or open...  Is this really necessary?

I am probably going to leave the back door off, but I did want to put on the
front door, since it has the cool dark plexiglass which will look cool with
LED and
other lights behind it...(just for cool geek factor).  Also was thinking
with the top fans to maximize the air flow I should have it somewhat
closed...

In general, is it best to put the largest heat generating systems at the top
or bottom of a somewhat closed rack?  I'm thinking top is best, if it's
"safe" weight wise.. but
didn't know if it's a requirement, etc.  Also any reason to leave any space
between the systems on the rack?  Does that improve air flow?  Cause dead
air areas?

Any suggestions, help, recommendations greatly appreciated!!

Earl