RMC communication to VIOS is busy or timed out

There are several issues that can cause Resource Monitoring and Control (RMC) connection problems.

RMC communication issue
Performing many concurrent migrations causes RMC to shut down

RMC communication issue

If you are getting error messages in PowerVC while an RMC connection runs on Virtual I/O Servers, then there might be a configuration issue. You might see error messages that indicate the following information: RMC communication timed out on the Virtual I/O Servers, Virtual I/O servers are too busy to process the request, or RMC is in a busy state.

Explanation

Network Configuration: If the wrong DNS or host lookup information is provided, then it can cause the Virtual I/O Servers to have a slow response.
Fibre Channel Configuration: If the Fibre Channel port connection is not configured properly, then the lsnports command on the Virtual I/O Servers can take a long time. When the lsnports command delays, it can potentially cause other requests to time out.

Resolution

To resolve this issue, validate your VIOS network and storage configuration.

Performing many concurrent migrations causes RMC to shut down

Performing many concurrent migrations can cause the RMC connection to be moved to Inactive state. In that case, the deployed virtual machines will also be in Inactive state in PowerVC. Additionally, other operations that rely on the RMC connection will fail.

Explanation

This is a known problems in HMC versions earlier than 8.5.0.

Resolution

The RMC connection should start running again when the activity slows. At that point, the virtual machines should come out of Inactive state.