assuming /data/ is an NFS mount point already, enable it as storage for vdisks and configs
virsh pool-list
virsh pool-dumpxml default > pool.xml
virsh pool-destroy default
vi pool.xml
<path>/data/guests</path>
mkdir -p /data/guests/
virsh pool-create pool.xml
virsh pool-list
mkdir -p /data/guests/ ifconfig virbr0
and install some guests
to be able to talk to the other hypervisors and enable the farm, you will have to share a few SSH keys.
to migrate a guest, make sure the machine type is compatible on both ends,
kvm -M ?
and fix it (DO NOT USE the pc alias that is pointing to different latest versions depending on the hypervisors – choose the latest available on all hypervisors e.g. pc-i440fx-2.5) if required,
virsh shutdown GUESTNAME
virsh edit GUESTNAME
<os>
<type arch='x86_64' machine='pc-i440fx-2.5'>hvm</type>
<boot dev='hd'/>
</os>
the available virtual network devices can be displayed as such,
qemu-system-x86_64 -net nic,model=? /dev/null
e.g.,
qemu: Supported NIC models: ne2k_pci,i82551,i82557b,i82559er,rtl8139,e1000,pcnet,virtio
replacing rtl8139 with virtio,
<interface type='bridge'>
<mac address='xx:xx:xx:xx:xx:xx'/>
<source bridge='xenbr0'/>
<model type='virtio'/>
<driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5' rx_queue_size='256' tx_queue_size='256'>
<host csum='off' gso='off' tso4='off' tso6='off' ecn='off' ufo='off' mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off' ecn='off' ufo='off'/>
</driver>
</interface>
you may also have to disable caching on the virtual drive,
<driver name='qemu' type='qcow2' cache='none'/>
refs https://access.redhat.com/solutions/158363
you will then be able to live-migrate,
virsh -c qemu+ssh://ANOTHER-KVM-SRV/system list virsh migrate GUESTNAME qemu+ssh://ANOTHER-KVM-SRV/system
http://ask.xmodulo.com/change-default-location-libvirt-vm-images.html
https://mike42.me/blog/libvirt-migrate-a-vm-from-qemusession-to-qemusystem
https://wiki.libvirt.org/page/Failed_to_connect_to_the_hypervisor
http://blog.programster.org/kvm-offline-migration
https://libvirt.org/migration.html
https://libvirt.org/formatdomain.html
https://libvirt.org/formatdomain.html#elementsNICS
https://wiki.ubuntu.com/QemuKVMMigration
https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1617214
https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1637438
https://www.linux-kvm.org/page/Management_Tools
https://www.linux-kvm.org/page/Networking
https://www.redhat.com/archives/libvirt-users/2015-February/msg00024.html
https://access.redhat.com/errata/RHSA-2016:2577