[slurm-users] How to delay the start of slurmd until Infiniband/OPA network is fully up?

[Max Rutkowski]

Hi Ward,

Am 10.11.2023 um 19:45 schrieb Ward Poelmans:
> Hi Ole,
>
> On 10/11/2023 15:04, Ole Holm Nielsen wrote:
>> On 11/5/23 21:32, Ward Poelmans wrote:
>>> Yes, it's very similar. I've put our systemd unit file also online 
>>> on https://gist.github.com/wpoely86/cf88e8e41ee885677082a7b08e12ae11
>>
>> This might disturb the logic in waitforib.sh, or at least cause some 
>> confusion?
>
> I had never heard of these cards. But if they behave like infiniband 
> cards, is there also an .../ports/1/state file present in /sys with 
> the state? In that case it should work just as well.
>
> We could also change the glob '/sys/class/infiniband/*/ports/*/state' 
> to only look at devices starting with mlx. I have no clue how much 
> diversity is out there, we only have Mellanox cards (or rebrands of 
> those).
>
>> IMHO, this seems quite confusing.
>
> Yes, I agree.
>
>> Regarding the slurmd service:
>
>> An alternative to this extra service would be like Max's service file 
>> https://github.com/maxlxl/network.target_wait-for-interfaces/blob/main/wait-for-interfaces.service 
>> which has:
>> Before=network-online.target
>>
>> What do you think of these considerations?
>
> I think Max his approach is the better one. We only do it for slurmd 
> while his is completely general for everything that waits on network. 
> The downside is probably that if you have issue with your IB network, 
> this will make it worse ;)
That's why we do have a limit in there which will allow the boot to 
complete even without the network coming up. In case we need to log in 
and check the server. The script is made to delay it up until a timeout 
is reached. And yes, we used a more general approach since our issue 
actually was the network not coming up fast enough for our NFS mounts 
which are also used by Slurmd at our site.
>
> Ward