It is a common use case that nodes need some maintenance and the admin knows the maintenance window in advance. It is difficult to plan such a maintenance window(s) in the PBS now. This new feature enhances reservations in order to provide proper maintenance windows.
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- Visibility: public
- Change Control: Stable
- Synopsis: The new option allows submitting a special reservation and this reservation is allowed to 'run' on unavailable nodes.
- Details: pbs_rsub with '--hosts' option is allowed to be run only by managers and operators. The resources 'place' and 'select' are generated automatically and they are forbidden to combine with '--hosts'. Combining these resources with '--hosts' results in printing 'usage' help.
- The syntax of pbs_rsub with '--hosts' option requires list of hosts: ' <host1> <host2> <host3> ...'
- The placement of this reservation is always: '-l place=exclhost'
- The select is generated by the hosts like this: '-l select=host=<host1>:ncpus=<ncpus_host1>+host=<host2>:ncpus=<ncpus_host2>+host=<host3>:ncpus=<ncpus_host3>+...'
- The resv_nodes of this reservation is created in order to request all the ncpus of all vnodes on requested hosts.
- This reservation is confirmed immediately after submission by the pbs_rsub command and overlapping reservations are degraded and will be reconfirmed in the next scheduler iteration.
- The resv_nodes of overlapping reservations is modified and the requested vnodes are removed from the resv_nodes. This means that for running reservations no new job will start on overlapping nodes.
- Overlapping running jobs are ignored and it is up to the administrators to deal with these jobs.
- Reservation submitted with '--hosts' ignores resv_enable attribute on nodes.
- The reservation prefix is 'M', which stands for maintenance.
- Submitting this reservation will not invoke the scheduler iteration.
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