If established KVM session is being interrupted unexpectedly - it can remain in active state from the system point of view. In case when KVM session timeout is not set
in the system further attempts to connect to KVM console fail with the following message:
There are two ways listed in troubleshooting guide to fix the issue.
1. Connect to the server iBMC through SOL, and clear other users by restarting the iBMC
2. Restart the CMC.
(Also we can use a "shared" mode in this case, which has a limit of two simultaneous connections, but in case of multiple broken sessions it can also fail)
But there are situations when these two ways are useless, for example, if the system is on remote site and only one management module is connected to network. Then,
there is no physical access to connect through SOL. Also we can't remove the management module otherwise it will hot swap with spare one, which is not connected.
In such case, we can use the following method.
1. connect to the system via CLI
2. run the following command: smmset -d kvmtimeout -v partitionId 1
where "partitionID" is the ID of required partition. This command will set the timeout for inactive KVM sessions to that partition to one minute.
3. wait for more than one minute.
4. run the following command in CLI: smmset -d kvmtimeout -v partitionId time
where "time" is time interval in minutes, to set the timeout to a more usable value, like one hour or whatever.
After these steps all active KVM sessions to the selected partition will be cleared, and we will be able to open a new one.
The root cause of this issue is zero (which means no timeout) or very long timeout for inactive KVM sessions.
To fix the issue we have to set the KVM session timeout to 1 minute and wait, after 1 minute all active sessios will be cleared.
To avoid such problems it is recommended to set this timeout to a reasonable value.