[slurm-users] About x11 support

[Mahmood Naderan]

I think I know what is going wrong. Actually the bug is not related to
slurm or rocks itself. It is a result of some mismatches due to the update
of softwares including ssh, centos, rocks and slurm.

Recently, I have updated my rocks using "yum update". The result was
fetching the latest packages of Centos 7 (1804). I hit a problem that I was
unable to ssh to the nodes while passwordless ssh was working before the
update. See my discussion at [1].
With the help of Trevor [2], I was able to fix the problem. Please see the
technical comment from him in the post.

So, I am *guessing* that the latest version of slurm is not compatible with
1804 from Centos. In other word, something has been added/fixed in the ssh
library which is now causing some mismatches.




>and do you have in ~/.ssh/ and an ssh key named "id_rsa" and is
passwordless ?

Actually there is no id_rsa in my home for host based authentication.

[mahmood at rocks7 ~]$ cat .ssh/known_hosts
localhost ecdsa-sha2-nistp256
AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBNLjMdBkI636zSWU1N/dns3qHqc7Dr8JH/ulb2xryFM39Rk8p/4DIbkaV05fMpS6nXeJUjSY2X7U14bPRoiEeU4=
[mahmood at rocks7 ~]$ ls .ssh/
known_hosts
[mahmood at rocks7 ~]$ ssh compute-0-3 -Y
Last login: Tue Nov 20 16:45:13 2018 from rocks7.local
Rocks Compute Node
Rocks 7.0 (Manzanita)
Profile built 10:57 15-Nov-2018

Kickstarted 11:17 15-Nov-2018
[mahmood at compute-0-3 ~]$ xclock
^C




>So that looks like for some reason your display is set to :0 (or similar).
Are
>you by some chance trying to run this on an X server on the console of
rocks7?

>That also looks like an error you should look into fixing first.


I think that is caused by the issue that I described above.



[1]
https://lists.sdsc.edu/pipermail/npaci-rocks-discussion/2018-November/072367.html
[2]
https://lists.sdsc.edu/pipermail/npaci-rocks-discussion/2018-November/072380.html



Regards,
Mahmood




On Tue, Nov 20, 2018 at 2:58 PM Chris Samuel <chris at csamuel.org> wrote:

> On Tuesday, 20 November 2018 2:51:26 AM AEDT Mahmood Naderan wrote:
>
> > With and without --x11, I am not able to see xclock on a compute node.
> >
> > [mahmood at rocks7 ~]$ srun --x11 --nodelist=compute-0-3 -n 1 -c 6
> --mem=8G -A
> > y8 -p RUBY xclock
> > srun: error: Cannot forward to local display. Can only use X11 forwarding
> > with network displays.
>
> So that looks like for some reason your display is set to :0 (or similar).
> Are
> you by some chance trying to run this on an X server on the console of
> rocks7?
>
> > [mahmood at rocks7 ~]$ rocks run host compute-0-3 "yum list libssh2-devel"
> > Warning: untrusted X11 forwarding setup failed: xauth key data not
> generated
>
> That also looks like an error you should look into fixing first.
>
> All the best,
> Chris
> --
>  Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC
>
>
>
>
>
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