21 May
2019
21 May
'19
12:34 p.m.
I might think far more "obsolete" than "bad idea". It worked very
well
for the mainframe folks.
--
Will
On Tue, May 21, 2019 at 1:50 PM Jay West via cctalk
<cctalk at classiccmp.org> wrote:
No modern datacenter that I have seen still uses a raised floor *OTHER THAN* about 3
inches for a ground plane. There is a reason for that... the old idea of forced cooling
under the floor and mixing power & data cables there has been found to be a truly bad
idea.
Power in most any modern datacenter is via "track lighting" rails directly over
the row of racks. Ex: https://www.starlinepower.com/busway/
HVAC units are generally not inside the datacenter any longer either, nor are UPS's.
These cause access control issues with vendors doing maintenance and raises issues for
publicly traded companies that must meet certain control & accountability standards.
Not to mention locating them on the datacenter floor can cause issues with cool air
routing. So these days the hot and cold aisles are alternating, with a windsock/tube above
the racks for cold air delivery to the front and an 8 foot or so fan built in the hot
aisle wall. This is the optimum place for particle (smoke) sensors as well. That design
also lets in certain situations outside air to be used.
So to say you "definitely need a raised floor for a datacenter" is only true if
you are trying to create a period replica. A modern datacenter built that way... well...
not sure any self-respecting contractor would build one 'the old way' :)
J
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Adrian Stoness via
cctalk
Sent: Tuesday, May 21, 2019 12:03 PM
To: Patrick Finnegan <pat at vax11.net>; General Discussion: On-Topic and Off-Topic
Posts <cctalk at classiccmp.org>
Subject: Re: Pleas ID this IBM system....
all systems have their advantages disadvantages it all depends on what your doing and
designs u choose. personaly i think raised floor and tray above are best then u keep all
ur power below away from ur data lines plus but then ur setup is only as good as the
lazyest tech u get comming in running stuff.
On Tue, May 21, 2019 at 11:38 AM Patrick Finnegan via cctalk < cctalk at
classiccmp.org> wrote:
On Tue, May 21, 2019, 04:13 Christian Corti via
cctalk <
cctalk at classiccmp.org> wrote:
You definitely need a raised floor
for a data center. You need it for forced air cooling and for
running the water and condensate pipes.
Ductwork doesn't have to be below the floor. Modern co-lo facilities
that I have been in (such as Switch Supernap) don't have a raised floor.
Plumbing (unless you're doing aisle containment or RDHx) shouldn't run
through the IT space in the data center.
Cooling water to racks should be dewpoint adjusted, so you don't need
condensate drains inside the DC.
And overhead trays are much more difficult to
work with if you want to lay new cables because
you have to climb up
and down the ladder all the time, moving the ladder from here to
there and back to here...
I solved that by having multiple ladders. In my experience, it's a lot
easier than trying to reach through a cluttered raised floor under racks.
The only good reason that I have seen in this thread for a raised
floor is to match older equipment that routes cables downwards.
Pat