You can run the optmem command from the Hardware Management Console (HMC) command line on POWER7® processor-based servers with firmware at level 7.6, or later, to start a Dynamic Platform Optimizer (DPO) operation or stop a DPO operation that is currently running.

1. From the HMC command line, type the following command to start a DPO operation:

    optmem -m managed-system -o start -t affinity [-p partition-names | --id partition-IDs] 
   [-x partition-names | --xid partition-IDs]

   Where:
   • -x partition-names or --xid partition-IDs specifies the list of logical partitions or logical partition IDs that must not be affected by the optimization operation.
   • -p partition-names or --id partition-IDs specifies the list of logical partitions or logical partition IDs that must be optimized
2. To stop a currently running DPO operation, complete the following steps:
   1. From the HMC command line, type the following command to list the DPO operation that is currently running:

      lsmemopt -m managed-system

   2. From the HMC command line, type the following command to stop the DPO operation:

       optmem -m managed-system -o stop [--optid ID]

      Where:
      • --optid is an optional parameter that identifies the DPO operation to be canceled.
      • ID is the value returned by the lsmemopt command.
      Attention: Stopping a DPO operation before completion might worsen the affinity state of the system as compared to the affinity state of the system when the DPO operation was started.