You reported your issue on commit rather than copy as in the RH bug.
So looking into that more specific.
$ virsh snapshot-create-as --domain testguest snap1 --diskspec vda,file=/var/lib/uvtool/libvirt/images/vda-snap1.qcow2 --disk-only --atomic --no-metadata
# touch a file in guest
$ virsh snapshot-create-as --domain testguest snap2 --diskspec vda,file=/var/lib/uvtool/libvirt/images/vda-snap2.qcow2 --disk-only --atomic --no-metadata
# touch a file in guest
This gave me a two stage snapshot list
$ sudo qemu-img info --backing-chain /var/lib/uvtool/libvirt/images/vda-snap2.qcow2
image: /var/lib/uvtool/libvirt/images/vda-snap2.qcow2
[...]
backing file: /var/lib/uvtool/libvirt/images/vda-snap1.qcow2
[...]
image: /var/lib/uvtool/libvirt/images/vda-snap1.qcow2
[...]
backing file: /var/lib/uvtool/libvirt/images/testguest-clone5.qcow
backing file format: qcow2
[...]
image: /var/lib/uvtool/libvirt/images/testguest-clone5.qcow
In "virsh domblklist testguest" this moved me back from:
vda /var/lib/uvtool/libvirt/images/vda-snap1.qcow2
to
vda /var/lib/uvtool/libvirt/images/testguest-clone5.qcow
You reported your issue on commit rather than copy as in the RH bug.
So looking into that more specific.
$ virsh snapshot-create-as --domain testguest snap1 --diskspec vda,file= /var/lib/ uvtool/ libvirt/ images/ vda-snap1. qcow2 --disk-only --atomic --no-metadata /var/lib/ uvtool/ libvirt/ images/ vda-snap2. qcow2 --disk-only --atomic --no-metadata
# touch a file in guest
$ virsh snapshot-create-as --domain testguest snap2 --diskspec vda,file=
# touch a file in guest
This gave me a two stage snapshot list uvtool/ libvirt/ images/ vda-snap2. qcow2 uvtool/ libvirt/ images/ vda-snap2. qcow2 uvtool/ libvirt/ images/ vda-snap1. qcow2 uvtool/ libvirt/ images/ vda-snap1. qcow2 uvtool/ libvirt/ images/ testguest- clone5. qcow uvtool/ libvirt/ images/ testguest- clone5. qcow
$ sudo qemu-img info --backing-chain /var/lib/
image: /var/lib/
[...]
backing file: /var/lib/
[...]
image: /var/lib/
[...]
backing file: /var/lib/
backing file format: qcow2
[...]
image: /var/lib/
Committing those onto the base worked as well:
virsh blockcommit testguest vda --active --verbose --pivot
Block commit: [100 %]
Successfully pivoted
In "virsh domblklist testguest" this moved me back from: uvtool/ libvirt/ images/ vda-snap1. qcow2 uvtool/ libvirt/ images/ testguest- clone5. qcow
vda /var/lib/
to
vda /var/lib/