[ale] Server room issues

[Bob Toxen]

On Thu, Apr 22, 2004 at 02:37:21AM -0400, Dow Hurst wrote:
> Here is a not so condensed listing of some advice from the list and others. 
> Read this as a rundown of a particular installation with some thoughts 
> injected.  I'd appreciate comments or advice if you want to add anything. 
> Names were blacked out to protect someone:
...

> 1.  A/C issues

>   3 separate systems, each with 0.5 needed capacity to cool server room, so 
>   1 can fail and be repaired w/out downtime on servers.  No redundant piping
> of coolant so that is a point of failure.  Two window units (if windows
> available) are installed as extra cooling capacity to handle either extra 
> heat
> load or main unit failure for only a short time.  The window units make use 
> of
> the window space which would have been a leak point for the A/C anyway.
I agree.

> Think of A/C and Power supply as a fixed capacity that is set when the room 
> is
> built.  No more A/C or Power will be added due to the expense.  So, plan for
> future heat load and power load for the next 5-10 years.
I agree.

> An ale.org member, Jonathon Glass, said this:
> "You should really look at the IBM e325 series (Opterons) for cooling.  I 
> have
> 4 of them (demo units) in a cluster.  I felt the cases while running a demo,
> and they were cool, if not cold, to the touch.  IBM has spent a lot of money
> on making these machines rack-ready, and cool running, and it has paid off."
I would not pay for name brand equipment.  You're just paying for the name.
Do buy quality power supplies, though.  For critical nodes use dual
power supplies, each fed from a different circuit.  Get competitive quotes.

> Also he said:
> "How big are the Opteron nodes?  Are they 1,2,4U?  How big are the power
> supplies?  What is the maximum draw you expect?  Convert that number to 
> figure
> out how much heat dissipation you'll need to handle.
*I'm* not impressed with IBM's quality.  We had a problem with them at
a well-known client's systems at Mindsproing's Colo site where the one
non-redundant component in each of several boxes failed within a short time
and took down their site.  Because it was non-standard equipment, I could
not simply go to MicroCenter or Monarch and buy a replacement.  They were
down for almost 12 hours.  Very bad.  IBM *was* good about delivering
a technician and replacement parts within that 12 hours and replacing at
no cost to the client.

> 2.  Power issues

> 3.  Fire Detection versus Suppression

>   XXXXX felt suppression systems might endanger the life of someone in the
> server room when actuated, so a fire detection system was installed.  This
> detection system is wired into the A/C and power so can turn them off if 
> fire
> is present.  The logic is that the A/C would be the primary point for a fire
> to start or a overheating circuit so cutting power to A/C and servers would 
> be
> most likely to stop the problem.
Fire suppression isn't really risky.  If the place is on fire it's time to
get the bleep out anyway.

The reason for the fire detection/suppression system to shut off the
A/C and computers is to stop their fans from supplying more oxygen to
the fire.  Statistically, the fire is far more likely to start from one
of the many computer devices than from one of the three A/C units.

> 4.  Room Location Caveats

>   Don't be far from the loading dock to ease the movement of equipment into
> the server room.  Elevators, stairs, tight turns, doorways, and 
> possibilities
> of flooding and corrosive gases are not obstacles we want our room to be 
> near.
Yup.

> __________________________________________________________
> Dow Hurst                  Office: 770-499-3428            *
> Systems Support Specialist    Fax: 770-423-6744            *
> 1000 Chastain Rd. Bldg. 12                                 *
> Chemistry Department SC428  Email:   dhurst at kennesaw.edu   *
> Kennesaw State University         Dow.Hurst at mindspring.com *
> Kennesaw, GA 30144                                         *
> ************************************************************
Bob