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8.3.2.2. Memory Backing
The optional
<memoryBacking> element may contain several elements that influence how virtual memory pages are backed by host pages.
Red Hat Enterprise Linux 6.6 and later includes support for locking a virtual machine's memory pages in the host memory with the
locked parameter.
Setting
locked prevents the host from swapping out memory pages belonging to the guest, which can cause latency. Add the following to the guest XML using the virsh edit command to lock the virtual memory pages in the host's memory:
<memoryBacking>
<locked/>
</memoryBacking>
Important
When setting
locked, a hard_limit must be set in the <memtune> element to the maximum memory configured for the guest, plus any memory consumed by the process itself.
Setting
nosharepages prevents the host from merging the same memory used among guests. To instruct the hypervisor to disable share pages for a guest, add the following to the guest's XML using the virsh edit command:
<memoryBacking>
<nosharepages/>
</memoryBacking>
