Changing the amount of allocated memory or the number of CPUs can be done either by editing the XML definition for the VM or using the libvirt toolset. In this recipe, we are going to look at examples of changing both the memory and the CPU count for a KVM instance.
For this recipe, we are going to need the following:
- A running KVM instance with 1 GB of memory, 1 CPU allocated, and console access
- The
libvirtpackage - A guest OS with at least 4 GB of available memory and minimum of 4 CPUs
To inspect and update the memory and CPU resources assigned to a virtual machine follow the process outlined here:
- Get memory statistics for the running instance:
root@kvm:~# virsh dommemstat kvm1 actual 1048576 swap_in 0 rss 333644 root@kvm:~#
- Update the available memory for the VM to 2 GB:
root@kvm:~# virsh setmem kvm1 --size 1049000 root@kvm:~#
- Stop the running instance:
root@kvm:~# virsh destroy kvm1 Domain kvm1 destroyed root@kvm:~#
- Set the...