Previously, VDSM uses a high number of system threads, and caused high resource usage making the system slow. With this update, a new option, cpu_affinity, in vdsm.conf was added so users can tune the CPU affinity. The option is disabled by default.
To enable the new option, edit the vdsm.conf file. Under [vars] section, edit the 'cpu_affinity' option. It accepts a comma separated whitelist of CPU cores on which VDSM is allowed to run. The default is "", meaning VDSM can be scheduled by the operating system to run on any core. Some valid examples include: "1", "0,1", "0,2,3".
The resource usage of VDSM dramatically improves when the cpu_affinity is enabled. It is recommended to enable the cpu_affinity option if VDSM uses too much CPU. It is also recommended to set the affinity to one CPU only and to avoid cpu #0, because other system task may default to that CPU.