Note
Notes:
- Nodes with CPUs from different vendors, e.g. Intel and AMD, cannot be added to same CPU pools.
- Before adding nodes to a pool stop all virtual machines and containers on the node.
The easiest way to add a node to a CPU pool is to run the following command on it:
# cpupools join
The node will be added to a default CPU pool.
Default pools have the following features and limitations:
-
The naming pattern is
default_{intel|amd}N, e.g.,default_intel0,default_amd0, etc. - A preset, unchangeable basic CPU mask provides maximum hardware compatibility at the expense of advanced CPU features. Different CPU features masks are used for different CPU vendors.
-
Nodes which do not support the basic CPU features mask are placed in different default CPU pools, e.g.,
default_intel1,default_amd2, etc. - Nodes cannot be added to specific default CPU pools on purpose.
To make sure that as many common CPU features as possible are enabled for nodes in a pool for best performance, you can move the required nodes to a custom CPU pool. To do this:
-
On each node to be added, run the cpupools move command. For example:
# cpupools move mypoolThe node will be moved to the CPU pool
mypool. If the CPU pool does not exist, it will be created. -
On any node in the new pool, run the
cpupools recalccommand to update the CPU features mask and make sure that as many common CPU features as possible are enabled. For example:# cpupools recalc mypoolNote
Note: Custom CPU pools are created with the same basic CPU features mask as default pools.
The general recommendation is to group nodes with CPUs of the similar microarchitecture, generation, or family as they have similar features. This way most of the CPU features will remain available for nodes after applying the CPU features mask to the pool. This approach will help ensure the best possible performance for nodes and at the same time guarantee live migration compatibility.
