Steps

Disable Power Off and Auto-Start Partitions

1. Disable "Power off when the last logical partition is shut down" using the HMC properties general page for the server being upgraded.  For more information, see Systems Management for Servers in IBM Knowledge Center at https://www.ibm.com/support/knowledgecenter/8247-22L/p8ha1/systemmanagement.htm.
2. Notice whether "Service Partition" is set to "Unassigned".  After the partition is powered off, this value is set to "Unassigned".
3. Under Power On Parameters in the same properties page, set "Partition Start Policy" to "User Initiated"
4. Verify that "Power-On Side" is set to "Temporary" and "Keylock Position" is set to "Normal".  Correct these values as needed.
5. Save these settings.

Power off the server

1. Open a console for the ESS I/O server being upgraded.  If using the ESS Management Node, use the xCat rcons command (See https://xcat-docs.readthedocs.io/en/stable/guides/admin-guides/references/man1/rcons.1.html for information on rcons).  If using the HMC, use mkvterm from restricted shell or ssh (See https://www.ibm.com/support/knowledgecenter/en/POWER8/p8edm/mkvterm.html for information on mkvterm).
2. Log on to the I/O server as root.
3. Issue the command /sbin/shutdown -h now
4. Wait for the I/O server partition to power off.  This can be viewed from the HMC GUI Resources -> All Partitions.  From the EMS Management Node, rpower <nodename> status can be used in the same fashion to check the status of the partition (See https://xcat-docs.readthedocs.io/en/stable/guides/admin-guides/references/man1/rpower.1.html for information on rpower).
5. From the HMC, completely power off the I/O Server

Install the Memory

Follow instructions in IBM Knowledge Center to install the memory.  See https://www.ibm.com/support/knowledgecenter/en/5148-21L/p8han/p8han_83x_8rx_install_kickoff.htm.

Resume once the I/O server is powered up to Standby but before the I/O server partition started (Section 3, step 8 of the listed procedure).  The SSR verifies that the new memory is installed from the HMC properties->memory page.  Installed and Available matches the total new memory installed.  The SSR can also check for serviceable events that may have occurred during install as a part of verification that no problems were introduced during the installation of the new memory.

Configuring the new Memory and Activating the I/O Server Partition.

The procedure for activating I/O Server partition with additional memory assumes that the partition is configured with "All resources" which is required for Elastic Storage Server I/O Servers and the Management Server.

1. From the HMC GUI, under All Partitions, select with the checkbox the I/O Server Partition that is configured.
2. Under Actions, select Activate.
3. Change Partition Configuration from "Current Configuration" to the default profile listed.
4. Click Finish.

The I/O server can now boot with the new memory configured.  The command 'cat /proc/meminfo' can be used to verify the partitions memory accounts for new memory installed.

This ends the procedure