How can I oversubscribe processors?


Question: How can I oversubscribe processors?



The information presented here applies to Moab 9.1.1/9.1.2 and Torque

One can enter more processors in the nodes table than physically exist on a node. For example, given that node "compute00" physically has 4 processors, one can enter the following line in file /var/spool/torque/server_priv/nodes:

compute00 np=8

Upon restarting pbs_server, eventually Moab will recognize 8 procs on compute00. This is not immediate; however, restarting moab after pbs_server will cause the change to appear immediately.

Commands such as mdiag -n will show that there are 8 procs on compute00.

However, if Torque is compiled with cgroups enabled, moab/torque will not allow more than 4 jobs to be run on compute00.

If Torque is compiled without cgroups, then 8 jobs can be run on compute00 thus oversubscribing compute00 with respect to processors.



Last update:
2018-03-05 23:13
William Groves
Average rating:0 (0 Votes)

You cannot comment on this entry

Chuck Norris has counted to infinity. Twice.

Records in this category