[slurm-users] x11 forwarding not available?

[Olivier Sallou]

On 10/16/2018 03:04 PM, Jeffrey Frey wrote:
> Make sure you're using RSA keys in users' accounts -- we'd started setting-up ECDSA on-cluster keys as we built our latest cluster but libssh at that point didn't support them.  And since the Slurm X11 plugin is hard-coded to only use ~/.ssh/id_rsa, that further tied us to RSA.  It would be nice for the host and user key files to be configurable options; more configurable options for that plugin in general would be useful.

and rsa key needs to be password-less (a shame...)
>
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>> On Oct 16, 2018, at 4:47 AM, Tina Friedrich <tina.friedrich at it.ox.ac.uk> wrote:
>>
>> I had an issue getting x11 forwarding via SLURM (srun/sbatch) to work; ssh 
>> worked fine. Tracked it down to the host name setting on the nodes; as per 
>> RedHat/CentOS default, the hostname was set to the fully qualified. Turns out 
>> SLURMs X11 forwarding doesn't work with that; setting the hostnames to the 
>> short hostname made it all magically work. 
>>
>> Tina
>>
>> On Tuesday, 16 October 2018 09:29:01 BST Olivier Sallou wrote:
>>> On 10/16/2018 01:07 AM, Dave Botsch wrote:
>>>> Hi.
>>>>
>>>> X11 forwarding is enabled and works for normal ssh.
>>> I faced same issue, with ssh x11 working as expected on compute nodes,
>>> but not with slurm -x11.
>>>
>>> I patched slurm locally to make it work.
>>>
>>> what you can try to see if it is the same issue:
>>>
>>>
>>> srun -n1 --pty --x11 --pty bash
>>>
>>>
>>> # xterm
>>> // you should have an authorization failure error
>>>
>>> // on connected node
>>> # xauth list
>>>
>>> you will have a list of MAGIC COOKIE like
>>>
>>> myslurmmaster/unix:10  MIT-MAGIC-COOKIE-1  YYYYYY
>>> myslurmnode/unix:52  MIT-MAGIC-COOKIE-1  XXXXXX
>>>
>>> # echo $DISPLAY
>>> localhost:52.0
>>>
>>>
>>> To make it work manually I did (of course adapting node names and
>>> display port number):
>>>
>>> xauth remove myslurmnode/unix:52
>>> xauth add localhost:52.0
>>>
>>> then xterm (for example) worked.
>>>
>>> If this is the same problem, slurm can be easilly patched to work (can
>>> give you how)
>>>
>>> Olivier
>>>
>>>> Thanks.
>>>>
>>>> On Mon, Oct 15, 2018 at 09:55:59PM +0000, Rhian Resnick wrote:
>>>>> Double check /etc/ssh/sshd_config allows X11 forwarding on the node as it
>>>>> is disable by default. (I think)
>>>>>
>>>>>
>>>>> X11Forwarding yes
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Rhian Resnick
>>>>>
>>>>> Associate Director Research Computing
>>>>>
>>>>> Enterprise Systems
>>>>>
>>>>> Office of Information Technology
>>>>>
>>>>>
>>>>> Florida Atlantic University
>>>>>
>>>>> 777 Glades Road, CM22, Rm 173B
>>>>>
>>>>> Boca Raton, FL 33431
>>>>>
>>>>> Phone 561.297.2647
>>>>>
>>>>> Fax 561.297.0222
>>>>>
>>>>> [image] <https://hpc.fau.edu/wp-content/uploads/2015/01/image.jpg>
>>>>>
>>>>> ________________________________
>>>>> From: slurm-users <slurm-users-bounces at lists.schedmd.com> on behalf of
>>>>> Dave Botsch <botsch at cnf.cornell.edu> Sent: Monday, October 15, 2018 5:51
>>>>> PM
>>>>> To: slurm-users at lists.schedmd.com
>>>>> Subject: [slurm-users] x11 forwarding not available?
>>>>>
>>>>>
>>>>>
>>>>> Wanted to test X11 forwarding. X11 forwarding works as a normal user
>>>>> just ssh'ing to a node and running xterm/etc.
>>>>>
>>>>> With srun, however:
>>>>>
>>>>> srun -n1 --pty --x11 xterm
>>>>> srun: error: Unable to allocate resources: X11 forwarding not available
>>>>>
>>>>> So, what am I missing?
>>>>>
>>>>> Thanks.
>>>>>
>>>>> PS
>>>>>
>>>>> srun --version
>>>>> slurm 17.11.7
>>>>>
>>>>> rpm -qa |grep slurm
>>>>> ohpc-slurm-server-1.3.5-8.1.x86_64
>>>>> ...
>>>>>
>>>>>
>>>>> --
>>>>> ********************************
>>>>> David William Botsch
>>>>> Programmer/Analyst
>>>>> @CNFComputing
>>>>> botsch at cnf.cornell.edu
>>>>> ********************************
>>>>> --
>>>>> ********************************
>>>>> David William Botsch
>>>>> Programmer/Analyst
>>>>> @CNFComputing
>>>>> botsch at cnf.cornell.edu
>>>>> ********************************
>>
>> -- 
>> Tina Friedrich, Snr HPC Systems Administrator, Advanced Research Computing
>> Research Computing and Support Services, Academic IT 
>> IT Services, University of Oxford 
>> http://www.arc.ox.ac.uk
>>
>
> ::::::::::::::::::::::::::::::::::::::::::::::::::::::
> Jeffrey T. Frey, Ph.D.
> Systems Programmer V / HPC Management
> Network & Systems Services / College of Engineering
> University of Delaware, Newark DE  19716
> Office: (302) 831-6034  Mobile: (302) 419-4976
> ::::::::::::::::::::::::::::::::::::::::::::::::::::::
>
>
>
>
>

-- 
Olivier Sallou
Univ Rennes, Inria, CNRS, IRISA
Irisa, Campus de Beaulieu
F-35042 RENNES - FRANCE
Tel: 02.99.84.71.95

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