The change Dan refers to merged in Kilo. I assume that if you actually found this problem then you're using an earlier OpenStack, so it's worth noting that there's an outstanding backport: https://review.openstack.org/#/c/176768/
Matthew On Wed, May 20, 2015 at 3:21 AM, Daniel P. Berrange <berra...@redhat.com> wrote: > On Wed, May 20, 2015 at 06:11:26PM +0800, Luo Gangyi wrote: >> Hi devs, >> >> >> I find a serious problem when I try to live migrate a hybrid instance >> (instance based on local disk and cinder volume attached) . >> >> >> In current nova, such operation is allowed. >> >> >> But I don't think libvirt can deal with such condition correctly. >> >> >> When block migration of a hybird intance is triggered, nova will initiate >> a new connection to the volume in destination compute node and then >> call libvirt to do the block migration. >> >> However, libvirt doesn't distinguish local disk and a network volume, >> it may copy both local disk and cinder volume from source to destination. >> >> It is dangerous to write the same volume simutaneously on source and >> destination!! and apparently there is no need to do this! >> >> I believe we should do something to correct this, maybe patch libvirt? >> or just forbid user do such operation? > > Both. Nova now forbids this > > commit d667b6a63e80b2f8d6311c2cf224ba32628eed84 > Author: Chris St. Pierre <stpie...@metacloud.com> > Date: Wed Dec 3 16:16:34 2014 -0600 > > libvirt: Fail when live block migrating instance with volumes > > This raises an exception when attempting to live block migrate (nova > live-migration --block-migrate) an instance with attached volumes. > libvirt copies these volumes from themselves to themselves. At a > minimum, this is horribly slow and de-sparses a sparse volume; at > worst, this could cause massive data corruption. > > Closes-Bug: 1398999 > Change-Id: Ibcd423976bb9fea46e3e1cb23cc8e5cd944d8fc2 > > And work is being done to allow libvirt to be told to skip cinder > volumes when migrating: > > https://www.redhat.com/archives/libvir-list/2015-May/msg00345.html > > Regards, > Daniel > -- > |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| > |: http://libvirt.org -o- http://virt-manager.org :| > |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| > |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev