Denied reservation


My environment:

  • OpenPBS version: 20.0.0
  • Queues with distinct priority levels: LowPriorityQ, workq, HighPriorityQ
  • Execution hosts with: 1, 2 or 3 gpus (ngpu)
  • Attributes:
    resv_enable = True
    acl_resv_host_enable = False
    acl_resv_group_enable = False
    acl_resv_user_enable = False
    resv_enable = True

LowPriorityQ has a large number of jobs requiring ngpu=1 and workq has one queued job that requires ngpu=3 and this job never run.

Possible solution:
Create a reservation for ngpu=3 to run the job, but PBS deny the reservation submission:
pbs_rsub -R 202205271600.00 -D 24:00:00 -W delete_idle_time=60 -l select=ngpus=3 -I 10
R5.cgpusub DENIED

Why the reservation submission was denied?

Thannk you in advance!

Nodes cannot be in use by other jobs to be reserved. If you want you can convert your difficult job into an asap reservation using pbs_rsub -Wqmove.

If you don’t like the time of the corresponding reservation then nodes are hogged by jobs with overly long wall time limits.

BTW: if you make all your ‘easy’ jobs topjob_ineligible and set strict_ordering and backfill enabled and have a decent backfill depth the system will on each cycle calendar the N top jobs to avoid pushing them into the future, I.e. it will make such asap reservations during each cycle. But it relies on a decent job sort order and realistic wall time (or soft wall time) limits.

Hi Alexis,

The strict order with backfill solution worked great for me!

Thank you for your help!