The hypervisor means the layer that manages a virtual environment, like VMware, XEN or VirtualBox.
So the steal field, should be an interesting field to monitor, to detect problems or oversubscription of a virtualised environment. The field itself means the time the VM CPU has to wait for others VMs (virtual machines) finishing their turn (slice), or for a task of the hypervisor itself.
The st field is present in the
However, this thread confirms the steal field is not supported in VmWare VMs (I tested it in VMware 5.5 and I corroborate it). VirtualBox doesn't provide CPU steal time data also. It is supported by Xen and KVM virtual environments.
vmstat also has the same field in the CPU area, but only after Debian 8.
sar to work
sysstat data collection has to be enabled.
st: Time stolen from a virtual machine. Prior to Linux 2.6.11,
Related thread Tools for Monitoring Steal Time (st)
Further reading: CPU Time stolen from a virtual machine?
It’s the time the hypervisor scheduled something else to run instead
of something within your VM. This might be time for another VM, or for
the Hypervisor host itself. If no time were stolen, this time would be
used to run your CPU workload or your idle thread.