On Tue, May 01, 2018 at 12:35:05PM +0200, Gianluca Cecchi wrote: > On Tue, May 1, 2018 at 10:45 AM, Daniel P. Berrangé <berrange@xxxxxxxxxx> > wrote: > > > On Tue, Jan 30, 2018 at 01:17:21PM +0100, Gionatan Danti wrote: > > > Hi all, > > > on a fully patched CentOS 7.4 x86-64, I see the following behavior: > > > > > > - when creating a new volumes using vol-create-as, the resulting file is > > a > > > qcow2 version 2 (compat=0.10) file. Example: > > > > > > [root@gdanti-lenovo vmimages]# virsh vol-create-as default zzz.qcow2 > > > 8589934592 --format=qcow2 --backing-vol /mnt/vmimages/centos6.img > > > Vol zzz.qcow2 created > > > > Yes, for sake of backcompat we default to v2 unless something > > requires v3. You can't use vol-create-as to create a v3 image, > > you need to use the XML input. > > > > > BTW: in virt-manager of CentOS 7.4 by default qcow2 disks (see below for > zzz3.qcow2) are created with compatibility 1.1 (probably indirectly because > of its lazy refcounts feature enabled, as Daniel wrote): Yes, virt-manager explicitly turns on lazy refcounts if it sees a new enough QEMU, so will get v3 Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
