Appendix E: Considerations Before Upgrading
TORQUE is flexible in regards to how it can be upgraded.  In most cases, a TORQUE shutdown followed by a configure, make, make install procedure as documented in the TORQUE Administrator's Guide is all that is required. This process will preserve existing configuration and in most cases, existing workload.
  A few considerations are included below:
  
    - If upgrading from OpenPBS, PBSPro, or TORQUE 1.0.3 or earlier, queued jobs whether active or idle will be lost.  In such situations, job queues should be completely drained of all jobs.
- If not using the pbs_mom -r or -p flag, running jobs may be lost. In such cases, running jobs should be allowed to completed or should be requeued before upgrading TORQUE.
- pbs_mom and pbs_server daemons of differing versions may be run together.  However, not all combinations have been tested and unexpected failures may occur.
Upgrade Steps
  
    - Build new release (do not install)
- Stop all TORQUE daemons - See qterm and momctl -s
- Install new TORQUE - use make install
- Start all TORQUE daemons
E.1 Rolling Upgrade
  
the enablemomrestart option causes a MOM to check if its binary has been updated and will restart itself at a safe point when no jobs are running, making upgrades easier. This can be enabled in the MOM config file, but it is recommended to enable it with momctl.
  
    - Prepare the new version MOM package
- Install the MOM package on the compute nodes
- Run momctl -q enablemomrestart=1 -h :ALL