On Thu, 5 Sep 2002, Larry Beaulieu wrote:
>
> > Single post racks as you call them are often called relay racks. They
> > aren't for mounting equipment in they are for mounting patch panels and
> > stuff like that. Machines are too big to mount in them. Also you
> > should securly mount the relay racks to the ground.
> >
> > You should use cabinets for gear not relay racks.
>
> The issue with typical cabinets is with cooling; you have to
.... Lots of absolutely correct information about thermal issues in
equipment cabinets deleted.
...
> There usually aren't significant problems using relay racks as long as
A and B deleted, as relevent to both relay racks and cabinets.
> c) the front rails/ears on the equipment are strong enough to safely
> hold it on its own. When properly secured you can easily and
> safely mount even larger equipment like Cisco 12016's and Juniper
> M160s (been there, done that more than once). A lot of the rack-mount
> Sun gear also racks up OK.
Whoa Nellie!
Here I agree with John. Having worked with both cabs and relay racks, in
large datacenters and my basement, I have to disagree pretty strenuously.
The only reason I can see to favor relay racks over cabinets for anything
but patch panels is $$$. A relay rack costs less than $200, and a good
cab can run from about $1200 up to nearly $3K.
That said, regardless of how they are secured, for any equipment with any
weight or size at all, IMO a cabinet is required.
Ask the shuttle booster engineers. Just cause you got away with something
once or twice does not make it a Good Idea (tm).
The thermal issues, power, total cab weight, room between racks etc can
all be dealt with, but the reason to use a cabinet trumps them all: Safety
Relay racks are not designed to hold anything wider than their feet,
typically 12 inches, and that has to be centered on the legs.
Rackmounting Cisco routers (depth between 15 and 23 inches) in a
relay rack, using the mounting kit designed for a cabinet leaves the
entire weight of the unit extended beyond the center of balance of the
rack. How you secure it is unimportant here.
Any time you do mount something that big in a relay rack, it has to be on
a shelf, to keep the center of mass in line with the rack verticals.
You may get away with it once, or even for a while, but you're playing
beyond the bounds of good sense and sooner or later it will bite you, or
worse yet, someone else.
> It's also true that relay racks need to be properly secured, either
> directly bolted to the floor, or in the case of raised floor,
> using hardware to ultimately secure them to the subfloor.
That's true of cabinets as well, though not nearly as widely observed as
it should be.
No offense, but I if I have a choice, it always goes in a cab. If I
don't, well I have to start thinking about other choices.
- Mark
Mark Lamourine <[EMAIL PROTECTED]>
http://home.attbi.com/~mlamourine
17 Forest Street, Billerica, MA 01821
+1 978 671 9263
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