TrueNAS k3s-server uses more than 10% CPU

The k3s supposed to be the lightweight k8s, but it used more than 10% when no container running. The problem was reported when TrueNAS running as VM.

This issue also caused high disk utilization, which caused whole system slow, huge IO wait.

Unset Pool

There is a zpool called ix-applications created for k3s. To stop k3s process, needs to unset pool in Apps => Settings => Unset Pool.

After Unset Pool, the CPU utilization dropped from 70% to 5%.

When changing CPU type for VM via Virtual Machine Manager, following error occurred,

Error changing VM configuration: unsupported configuration: Attribute migratable is only allowed for host-passthrough CPU

To solve this issue, I had to delete the VM then create it again using the same disk image.