[HTCondor-users] Removing / disabling GPUs without stopping jobs

[Joan Josep Piles-Contreras <jpiles@xxxxxxxxxxxxxxxx>]

Hi,

In a partitionable slot, is there any way to disable a given GPU without 
restarting the startd, or in any case to prevent it from being assigned 
to new jobs? In short, what `OFFLINE_MACHINE_RESOURCE_<name>` already 
does, just without restarting the startd (i.e. without stopping already 
running jobs).

We have some nodes with multiple GPUs, and from time to time one of the 
GPUs crashes and ends up in some unstable state. The node then becomes a 
"black hole" because it keeps accepting jobs that then just crash.

We can already detect it, but fixing it usually requires a reboot 
(trying to reset the card doesn't always do the trick, we already tried).

What we ideally would want is to prevent the non-working card from being 
assigned to new jobs until we can find the right spot to reboot the 
node, because some jobs need a long time to run, and we want to make it 
as little intrusive as possible.

With static slots it would be easy to just set START to false in the 
slot, but would it be possible to do something equivalent with dynamic 
slots?

I fear the system will be very confused if we make the START expression 
conditional on the assigned GPU...

Best,

Joan

--
Dr. Joan Josep Piles-Contreras
ZWE Scientific Computing
Max Planck Institute for Intelligent Systems
(p) +49 7071 601 1750