Il 2022-11-26 10:36 Gionatan Danti ha scritto:
Il 2022-11-21 10:30 Peter Krempa ha scritto:
In regards to the 'compat' option in terms of snapshots/blockcopy, we
don't set it and thus use the qemu default. Since both operations
create
a new image with an existing qemu instance, the default new qemu
format
is okay.
Hi, some idea on why creating a qcow2 volume and snapshotting it via a
backing file results in two qcow2 files with different format (v2 vs
v3)? Example below:
# volume creation
[root@whitehole ~]# virsh vol-create-as default zzz.qcow2 1G --format
qcow2
Vol zzz.qcow2 created
[root@whitehole ~]# qemu-img info /var/lib/libvirt/images/zzz.qcow2
image: /var/lib/libvirt/images/zzz.qcow2
file format: qcow2
virtual size: 1 GiB (1073741824 bytes)
disk size: 16.5 KiB
cluster_size: 65536
Format specific information:
compat: 0.10
compression type: zlib
refcount bits: 16
[root@whitehole ~]# file /var/lib/libvirt/images/zzz.qcow2
/var/lib/libvirt/images/zzz.qcow2: QEMU QCOW2 Image (v2), 1073741824
bytes
# snapshot creation
[root@whitehole ~]# virsh snapshot-create-as zzz --name zsnap1
--disk-only
Domain snapshot zsnap1 created
[root@whitehole ~]# qemu-img info /var/lib/libvirt/images/zzz.zsnap1
image: /var/lib/libvirt/images/zzz.zsnap1
file format: qcow2
virtual size: 1 GiB (1073741824 bytes)
disk size: 16.5 KiB
cluster_size: 65536
backing file: /var/lib/libvirt/images/zzz.qcow2
backing file format: qcow2
Format specific information:
compat: 1.1
compression type: zlib
lazy refcounts: false
refcount bits: 16
corrupt: false
extended l2: false
[root@whitehole ~]# file /var/lib/libvirt/images/zzz.zsnap1
/var/lib/libvirt/images/zzz.zsnap1: QEMU QCOW2 Image (v3), has backing
file (path /var/lib/libvirt/images/zzz.qcow2), 1073741824 bytes
Regards.
Hi all,
anyone with some ideas/suggestions?
Regards.
--
Danti Gionatan
Supporto Tecnico
Assyoma S.r.l. - www.assyoma.it
email: g.danti@xxxxxxxxxx - info@xxxxxxxxxx
GPG public key ID: FF5F32A8
