Installation guide

Chapter 24. Miscellaneous administration tasks
186
Identifying CPU and NUMA topology
The first step in deciding what policy to apply is to determine the host’s memory and CPU topology.
The virsh nodeinfo command provides information about how many sockets, cores and
hyperthreads there are attached a host.
# virsh nodeinfo
CPU model: x86_64
CPU(s): 8
CPU frequency: 1000 MHz
CPU socket(s): 2
Core(s) per socket: 4
Thread(s) per core: 1
NUMA cell(s): 1
Memory size: 8179176 kB
This system has eight CPUs, in two sockets, each processor has four cores.
The output shows that that the system has a NUMA architecture. NUMA is more complex and requires
more data to accurately interpret. Use the virsh capabilities to get additional output data on the
CPU configuration.
# virsh capabilities
<capabilities>
<host>
<cpu>
<arch>x86_64</arch>
</cpu>
<migration_features>
<live/>
<uri_transports>
<uri_transport>tcp</uri_transport>
</uri_transports>
</migration_features>
<topology>
<cells num='2'>
<cell id='0'>
<cpus num='4'>
<cpu id='0'/>
<cpu id='1'/>
<cpu id='2'/>
<cpu id='3'/>
</cpus>
</cell>
<cell id='1'>
<cpus num='4'>
<cpu id='4'/>
<cpu id='5'/>
<cpu id='6'/>
<cpu id='7'/>
</cpus>
</cell>
</cells>
</topology>
<secmodel>
<model>selinux</model>
<doi>0</doi>
</secmodel>
</host>
[ Additional XML removed ]
</capabilities>