[libvirt-users] virsh migrate --copy-storage-inc

Paul van der Vlis paul at vandervlis.nl
Sun Feb 10 11:11:42 UTC 2019


I use libvirt on machines without shared storage. My VM's have all one
qcow2-disk, with the same name as the VM.

When I want to migrate a VM, I check if there is an qcow2 image on the
other host with that name. When that's not the case, I copy the image
using rsync first. If the image excist, I don't do that, and I think
that "--copy-storage-inc" will do it.

But I don't know how intelligent "--copy-storage-inc" is. I use LVM
inside the VM's, and it's possible that I have changed the size of a
volume for example.

My questions:
Is "--copy-storage-inc" intelligent enough for such tasks?
Is there documentation what is done during migration? Is it using rsync?
Is it possible to make the migration process more verbose?
Is what I do a good way?

With regards,
Paul van der Vlis

BTW: this is what I do, sometimes the lines are broken wrong:
# Rsync image when not on the other host:
if test `ssh $other "if test -e /data/$vm.qcow2; then echo ja; else echo
nee; fi"` = "nee"; then
  echo "rsync..."
  rsync /data/$vm.qcow2 $other://data/$vm.qcow2
  if test $? = 0; then echo "gelukt"; else echo "niet gelukt"; exit; fi

# migrate
echo "migrate..."
virsh migrate --live --p2p --tunnelled --copy-storage-inc --persistent
--undefinesource --verbose $vm qemu+ssh://$other/system
if test $? = 0; then echo "gelukt"; else echo "niet gelukt"; exit; fi

Paul van der Vlis Linux systeembeheer Groningen

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