Adding a memory module

When the CPU usage of the ACOS cluster is low and there are sufficient idle storage resources but limited allocatable memory, it is recommended to increase the memory by adding a memory module to the host in the cluster.

Preparation

Before you shut down the node and increase the memory, check the status of the memory module to be installed and the cluster as follows to ensure proper preparation.

• Check the memory module in use and the memory module to be installed. Ensure that both the model and clock speed of the two memory modules are the same.

• For ACOS (VMware ESXi) clusters, refer to the official VMware documentation to manually migrate all virtual machines from the ESXi host whose memory is to be increased to other ESXi hosts.

Operation recommendation

Taking snapshots will disable the agile recovery mechanism when the host is in maintenance mode. Therefore, it is recommended to increase the memory at a time when no snapshot operations are being performed to avoid triggering a snapshot during host maintenance.

If special circumstances require adding a memory module during a snapshot operation, make sure you understand the risk described above before proceeding.

Procedure

1. Log in to AOC and set the node whose memory is to be increased to maintenance mode.

2. Shut down the node in AOC.

3. Install the new memory module onto the server and record the slot location, and then power on the server.

4. Log in to the IPMI console of the node and verify that the newly added memory module has been recognized by the IPMI console.

5. Log in to AOC and exit maintenance mode for this node.

6. Log in to this node using SSH and run the following command to check whether all services are running properly.

   sudo /usr/share/tuna/script/control_all_services.sh --action=status --group=role

7. Log in to AOC, go to the Overview page of the host, and check the Memory field under Host information to confirm that the memory capacity has been increased.