[QUOTE=fivemack;444783]The very best data-centre commissioning engineers probably arrange that at no stage in the commissioning process does the rack need to be manhandled across long damp grass.
[/QUOTE]
:davar55: Hehe... :tu:
[QUOTE]
Decidedly unfortunate news! The building I intend to install the rack in has ceiling-rafters which descend to less than 42U from the floor.[/QUOTE]Is there any room more than 42U wide in at least one direction? Then problem solved... :razz:

Pictures
 

1U servers; Rack with house for scale; back of rack showing all the free cables it came with; sad sideways rack is sad.

More relevantly to competent people, or at least people who have not decided that a 42U rack might be a sensible thing to own: whilst the spec document said "2x SFP+ Ports (82599 10 Gigabit Network Connection)" when I ordered them, there is actually only one usable SFP+ port - the metalwork has two side by side, but only one of them has a connector at the back. The spec document has now been changed and I have received a small discount for the thing not being as advertised.

This is a pity; I was hoping to connect the four machines as A-B C-D A-C B-D, which is all that linear algebra needs, and use Linux routing tables to make it possible to talk from A to D, but this obviously doesn't work with only one port per machine.

[QUOTE=fivemack;444796]1U servers; Rack with house for scale; back of rack showing all the free cables it came with; sad sideways rack is sad.[/QUOTE]Reminds me of my first full-time paid job or, rather, a year or so before I got paid.

While a grad student I worked with a small start-up in its very early stages. The company found premises in a building which had been a donkey stable. The hayloft became a large shared office and the room where the donkey lived was converted into the machine room. The expression on the DEC sales critter was wonderful when he realised that a shiny new VAX 11/750 (then about £100K list price) was to be installed in a room which then still had the drainage channels designed to keep the donkey's feet out of the donkey's excreta. There was even some straw left in odd corners. Of course, all was clean and level by the time the VAX was delivered.

[QUOTE=fivemack;444798]

This is a pity; I was hoping to connect the four machines as A-B C-D A-C B-D, which is all that linear algebra needs, and use Linux routing tables to make it possible to talk from A to D, but this obviously doesn't work with only one port per machine.[/QUOTE]

So what's your next step? Think you edited one of your messages with regards to MPI solution to adapt or I was half sleeping and read it somewhere else.

[QUOTE=fivemack;444783]Good news! The servers have arrived!
...
Decidedly unfortunate news! The building I intend to install the rack in has ceiling-rafters which descend to less than 42U from the floor.[/QUOTE]

They make "baby racks" that are a mere 14U or some variation around that. They're the type of thing you're likely to find in a utility closet or something, hosting a few switches or whatever and they didn't bother with a 2-post telco rack even.

Might find a decent used one...

Be thankful you didn't wind up with a taller 48U rack, I guess.

I hope you find some clever way of getting it upright where you planned... worst case I guess you can do it sideways but it sure takes the fun out of sliding servers in and out. Could be worse though.

[QUOTE=Madpoo;444922]They make "baby racks" that are a mere 14U or some variation around that. They're the type of thing you're likely to find in a utility closet or something, hosting a few switches or whatever and they didn't bother with a 2-post telco rack even.

Might find a decent used one...

Be thankful you didn't wind up with a taller 48U rack, I guess.

I hope you find some clever way of getting it upright where you planned... worst case I guess you can do it sideways but it sure takes the fun out of sliding servers in and out. Could be worse though.[/QUOTE]Or find someone with a hacksaw and a MIG welding kit.

[QUOTE=xilman;444929]Or find someone with a hacksaw and a MIG welding kit.[/QUOTE]

I know plenty of people with hacksaws, but I don't know hobbyist welders and it feels a bit much welding on rather thin painted steel plate to ask someone to do as a favour. My current kludge plan would be to cut it off at about 30U height, and then cut bits of sturdy timber to size and bolt them around the uprights to keep the uprights vertical and parallel; is there a fundamental flaw in that?

[QUOTE=pinhodecarlos;444845]So what's your next step? Think you edited one of your messages with regards to MPI solution to adapt or I was half sleeping and read it somewhere else.[/QUOTE]

I edited the message to suggest connecting the machines in pairs, but then realised I had returned all the SFP+ cables for a refund.

OK, now I have a new and exciting problem.

The servers don't have conventional-Ethernet hardware connected to the processor, their only network port is the 10Gbit SFP+ one and the Ethernet port at the front connects only to the (quite fancy) lights-out management server.

What do I need to attach four of them to my current 1Gbit network? My suspicion is quite an expensive switch; it seems that the 82559 10Gbit ethernet controller will [I]not[/I] step down to 1Gbit if I plug a 1Gbit SFP->1000BaseT into its SFP+ port, but that the sort of switches that Cisco sell [i]will[/i] do that, but that those switches cost more than the cluster.

Does anyone here know about enterprise networking to the point of being able to answer authoritatively whether [url]http://www.tp-link.com/en/products/details/cat-40_T1700G-28TQ.html[/url] treats the 10GE slots uniformly with the other ports, or whether it expects to route only *from* the gigabit ports *to* the 10GE SFP+ ones, rather than between the 10GE SFP+ ones and from 10GE SFP+ to gigabit?

Many inexpensive switches have two SPF+ ports. You could get two of those.

If the USB ports are USB3, you can get decent gigabit Ethernet dongles made by StarTech (I've had excellent luck with that brand in particular).