[mpich-discuss] Problems with running make

[Gus Correa]

On 03/03/2014 04:36 PM, Ron Palmer wrote:
> Thanks Reuti for your comments. I will peruse that FAQ detail.
>
> I just thought of the fact that each of these rack computers have 4
> ethernet sockets, eth0 - eth3... I could connect the cluster on a
> separate ethernet sockets via an extra switch not connected to the
> internet or any other computers, and accept all communication among
> them, and keep iptables up on the ethx connected to the outside world. I
> guess I would have to set up routing tables or something. Ah, more
> reading :-)
>
> Thanks for your help.
> Ron
>
Hi Ron

If those extra interfaces are not in use,
and if you have a spare switch,
you can setup a separate private subnet exclusively for MPI.
You need to configure the interfaces consistently (IP, subnet mask,
perhaps a gateway). Configuring them statically is easy:

https://access.redhat.com/site/documentation//en-US/Red_Hat_Enterprise_Linux/6/html-single/Deployment_Guide/index.html#s2-networkscripts-interfaces-eth0

Use a subnet that doesn't intersect the existent/original IP range.

http://en.wikipedia.org/wiki/Private_network

You could also create host names associated to those IPs (say
node01, node02, node02), resolve them via /etc/hosts on each computer,
set passwordless ssh across these newly named "hosts".
This may simpler/safer than messing with the iptables.

[Actually, the IP addresses you showed 192.168.X.Y, sound as a private
subnet already, not Internet, but that may be the subnet for your
organization/school/department already. So, you may set up a different
one on these three computers for MPI and very-local access.]

OpenMPI allows you to choose the interface that it will use,
so you can direct it to your very-local subnet:

http://www.open-mpi.org/faq/?category=tcp#tcp-selection

I hope this helps,
Gus


> On 4/03/2014 00:13, Reuti wrote:
>> Am 03.03.2014 um 01:34 schrieb Ron Palmer:
>>
>>> Gus,
>>> I have just replied with the details of the success, but I will
>>> clarify your questions here, if it helps next time.
>>>
>>> Re the actual application to be run, 'inversion', I have only
>>> received binaries. I used to run them on gainsborough (without mpi)
>>> and that worked fine.
>>>
>>> Home directories are not nfs shared, they are individual and
>>> separate, only the name is repeated.
>>>
>>> I had tried password free ssh in all directions and permutations.
>>>
>>> I had iptables down on sargeant and up on the other two.
>>>
>>> Yes, I installed the gcc-gfortran.x86_64 AFTER I took those
>>> screnshots, and the post install output was identical to the top one
>>> (sargeant).
>>>
>>> I am unsure about cpi and fortran...
>>>
>>> Stuff remaining to get sorted out:
>>> 1. Get that hyperthreading set up - what is your suggestions? Disable
>>> and let mpi manage the cores?
>> It depends on your applications, whether you can make use of it. Test
>> it with HT switched off, switched on and increase the number of
>> processes, until you see that any process is no longer running at 100%
>> and you judge that you don't tolerate this slow down.
>>
>> It's not uncommon to see an improvement up to 150% with HT turned on,
>> but not 200% (depending on the workload).
>>
>>
>>> 2. run mpiexec with iptables up, need to figure out what traffic to
>>> allow.
>> https://wiki.mpich.org/mpich/index.php/Frequently_Asked_Questions#Q:_How_do_I_control_which_ports_MPICH_uses.3F
>>
>>
>> -- Reuti
>>
>>
>>> Great many thanks to all, and Gus, Reuti and Rajeev in particular.
>>>
>>> Cheers,
>>> Ron
>>>
>>> On 3/03/2014 10:09, Gustavo Correa wrote:
>>>> Hi Ron
>>>>
>
>
>
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