Installation guide

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VMware ESX Server Administration Guide
An example output is:
The preceding output indicates that the virtual machine, with the specified ID,
occupies 51MB of memory on node 0, and no memory on node 1.
Note: In this preceding example, the memory affinity is set so that only pages
associated with node 0 are allocated for this virtual machine
(sched.mem.affinity = 0). If memory affinity had not been set, then typically
the output would have shown a more even distribution of memory between nodes 0
and 1. For more information, see Associating Future Virtual Machine Memory
Allocations with a NUMA Node on page 422.
Automatic NUMA Optimizations
By default, ESX Server balances virtual machines and their related data between the
available NUMA nodes. ESX Server attempts to maximize use of “local memory,” that
lies on the same NUMA node as the virtual machine that is running.
ESX Server automatically assigns each virtual machine to a temporary “home” NUMA
node. The virtual machine only runs on CPUs in the home node, with access to its
“local memory.”
Periodically, ESX Server compares the utilization levels of all NUMA nodes and
attempts to “rebalance” the nodes if one node has a higher utilization level than the
other nodes. ESX Server rebalances the nodes by changing a virtual machine’s “home”
NUMA node from the overutilized node to an underutilized node.
When the NUMA nodes are balanced, ESX Server again attempts to maximize use of
“local memory.” For additional information on this process refer to the numa man
page.
You may also set affinity manually as described in the next section. If you do so, then
ESX Server won’t automatically rebalance the nodes, and you must balance the NUMA
nodes to avoid overloading any single node.
Manual NUMA Optimizations
If you have applications that use a lot of memory or have a small number of virtual
machines, then you may want to optimize performance by setting your NUMA
optimizations manually. However, for most users, ESX Server’s automatic NUMA
optimizations, as described in the previous section, should provide you with good
performance.
Node# Pages/MB
0 13250/51
10/0