||The Distributed ASCI Supercomputer 3||
About the name...
preserve - Reserve compute nodes from cluster to run job
SYNOPSISpreserve [option] -# ncpus time
DESCRIPTIONpreserve is part of a reservation system, which users generally invoke via prun(1). There are several situations where users directly call preserve:
preserve and prun build on a reservation system that is partly based on goodwill: compute node reservation is implemented, but generally not strictly enforced. However, users sidestepping the reservation mechanism and accessing compute nodes directly will incur the wrath of both fellow users and the system administrators.
preserve reserves a number of cpus or nodes during the requested time (in seconds), by default 900 seconds (15 minutes), which is also the maximum allowed reservation during daytime. If no start time is specified explicitly, the reservation is allocated as soon as the requested number of processors is available. The users are themselves responsible to honor the required execution limits, or request an exception by email to the system administrators.
If cpus are requested (instead of nodes), preserve by default rounds the requested number of cpus upwards to a multiple of the number of cpus per node, i.e., 2 for DAS-2 and DAS-3. This ensures that there are no other jobs on the reserved nodes (from the same or another user) that might interfere.
Frank J. Seinstra -
Kees Verstoep - email@example.com