The Fair scheduler distributes CPU resources among the VEs, and controls CPU resource management.
It is a two-level implementation of fair-share scheduling strategy.
On the first level the scheduler decides which VE to give CPU time slice to, based on per-VE cpuunits values. On the second level the standard Linux scheduler decides which process to run in that container, using standard Linux process priorities and such.
OpenVZ administrator can set up different values of cpuunits for different containers, and the CPU time will be given to those proportionally.
Also there is a way to limit CPU time, e.g. say that this container is limited to, say, 10% of CPU time available.
...Stay tuned for more info...
Monitoring
The scheduler can be monitored by using the /proc/vz/vestat file.