Building a pacemaker cluster to manage Xen domU virtual machines the sysadm can choose between to different resource agents:
- the dedicated Xen resource agent (ocf:heartbeat:Xen)
- the libvirt based resource agent (ocf:heartbeat:VirtualDomain)
Both will support the usual start/stop operations and live migration between running nodes. The Xen ra implements the monitor action by running xm list (which I do know can be really slow sometime, leading to problems if the monitor timeout is set too low), the libvirt one uses virsh domstate (which I don’t know how it is implemented).
Overall, the two RA seem to be nearly identical in features.
Is there any reason to prefer one resource type over the other when planning and implementing a new cluster?
libvirt is a programming API allowing for developing applications that manage hypervisors. It is completely hypervisor-independent, meaning it can manage Xen, KVM, VMware, Hyper-V, etc., through the same API.
So if you want to build a system that is hypervisor-agonstic, or you’re running different types of hypervisors, you would want to use libvirt to manage them. This way you use the same code to perform an operation regardless of whether the underlying hypervisor is Xen, Hyper-V, KVM, VMware, or something else.
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