A job reservation can be used to place a hold on the user's account before a job starts to ensure that the credits will be there when it completes.
To create a job reservation use the command greserve:
greserve [-u user_name] [-p project_name] [-m machine_name] [-o organization] [-C queue_name] [-Q quality_of_service] [-P processors] [-N nodes] [-M memory] [-D disk] [-n job_name] [--application application] [-t wallclock_duration] [-s start_time] [-e end_time] [-T job_type] [-d reservation_description] [-X | --extension property=value...] [--debug] [-? | --help] [--man] [--quiet] [-v | --verbose] [-V | --version] [[-J] job_id]
Example 7. Creating a reservation
$ greserve -J PBS.1234.0 -p chemistry -u amy -m colony -P 2 -t 3600 Successfully reserved 7200 credits for job PBS.1234.0
|It is possible to establish a system default machine, project or user to be used in job functions (charge, reserve or quote) when left unspecified (see Server Configuration).|