Interactive jobs

The timeshare queue is always available to run a job, since it uses "job packing" (it can place multiple jobs on the same node). Because of this, it is an ideal queue to use for running interactive sessions, since they will start immediately.

To start an interactive session in the timeshare queue, simply type the command interact on an Oscar login node.

By default, this will create an interactive session that reserves 1 core, 4GB of memory, and 1 hour of runtime. 

You can change these default limits with the following command line options:

usage: interact [-n cores] [-t walltime] [-m memory] [-q queue] [hostname]

  Starts an interactive job in the 'timeshare' queue. This script wraps the
  'qsub -I' command.

options:
  -n cores     (default: 1)
  -t walltime  as hh:mm:ss (default: 1:00:00)
  -m memory    as #[k|m|g] (default: 4g)
  -q queue     (default: timeshare)
  hostname     only run on this hostname (default: none, use any available node)

For instance, to create a session with 8 cores and 64GB of memory for 4 hours, use:

interact -n 8 -m 64g -t 4:00:00

If you previously used a specific node for your calculations, and would like to use that same node, you can specify its hostname. For example, to run a session like above on the node 'smp8' use:

interact -n 8 -m 64g -t 4:00:00 smp8

Note, however, that specifying a node prevents the batch system from choosing the node in the timeshare queue that has the most available resources.

Finally, you can use a different queue with the -q option. However, you may experience long wait times if you use a queue other than timeshare or debug, since those queues are designed to have fast turn-around.