>
>
> 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.
So have I, at least with large datacenters (several people on this
list can confirm this); I'm not about to drill holes in the floors
of my house to mount racks.
> 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
In a roundabout way this can be a significant factor. For one
example, picture having to install ~190 Lucent TNTs, each with 720
modems (672 active + 48 hot spares), and you'll get the idea. Even
using relay racks presents significant challenges. It's way worse
when using cabinets; your costs will be considerably higher when
you also take into account footprint costs.
> cab can run from about $1200 up to nearly $3K.
If you buy in small quantities, yes.
> That said, regardless of how they are secured, for any equipment with any
> weight or size at all, IMO a cabinet is required.
Sorry, but I disagree. My experience says otherwise.
Also, note that I specifically pointed out "when properly secured".
This in part means that you also have to make provision for strong
support for the top of the racks as well.
>
> Ask the shuttle booster engineers. Just cause you got away with something
> once or twice does not make it a Good Idea (tm).
Significantly different application.
BTW every computer facility I've seen specifically designed to
maintain service during earthquakes do *not* use cabinets; they use
racks that have significant support from above. The theory behind
the design is that floor mounts will break away and the racks themselves
have some ability to sway during a major earthquake.
BTW, in reference to the comment someone else made re: harvard.net, they
aren't exactly a good example of how to build a good datacenter, unless you
want to learn about how to build one on the cheap.
> 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.
Rock, hard place. When fully populated they're furnaces.
(So are M160's, you have to wire them for 70A @ 48VDC.)
If you use cabinets you're risking other problems.
> 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.
As I mentioned above, rock, hard place. If you're dealing with
high densities of gear or high-wattage equipment you're risking
problems if you use cabinets.
> That's true of cabinets as well, though not nearly as widely observed as
> it should be.
Absolutely correct, but this wasn't brought up previously so
I'm not touching on it.
> 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.
No offense taken, none meant either. My experience obviously
differs from yours but there's no need for us to throw darts
at one another.
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