separated the final size issue into a separate bug here: https://bugs.launchpad.net/qemu/+bug/1103903
-- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1103868 Title: drive_mirror crashes on full disk copy of a resized disk with a backing file Status in QEMU: New Bug description: This bug was discovered using libvirt on ubuntu with a build of qemu 1.3 but it is trivailly reproducible with the curent git version. Repro steps: qemu-img create -f qcow2 base 32M qemu-img create -f qcow2 -o backing_file=base disk qemu-img resize /home/vishvananda/disk 64M qemu-system-x86_64 -drive file=disk,id=vda -vnc :1 -monitor stdio QEMU 1.3.0 monitor - type 'help' for more information (qemu) drive_mirror -f vda test Formatting 'test', fmt=qcow2 size=67108864 encryption=off cluster_size=65536 lazy_refcounts=off qemu-system-x86_64: /build/buildd/qemu-1.3.0+dfsg/block/mirror.c:129: mirror_run: Assertion `n > 0' failed. Aborted Note that the command works just fine if the front image is not resized: qemu-img create -f qcow2 base 32M qemu-img create -f qcow2 -o backing_file=base disk qemu-system-x86_64 -drive file=disk,id=vda -vnc :1 -monitor stdio or if the backing file is resized as well: qemu-img create -f qcow2 base 32M qemu-img create -f qcow2 -o backing_file=base disk qemu-img resize /home/vishvananda/disk 64M qemu-img resize /home/vishvananda/base 64M qemu-system-x86_64 -drive file=disk,id=vda -vnc :1 -monitor stdio or if we don't use -f when creating the mirror: QEMU 1.3.0 monitor - type 'help' for more information (qemu) drive_mirror vda test Formatting 'test', fmt=qcow2 size=33554432 backing_file='base' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off although in this final case the mirror is created the same size as the backing file which seems wrong: qemu-img info test image: test file format: qcow2 virtual size: 32M (33554432 bytes) disk size: 196K cluster_size: 65536 backing file: base backing file format: qcow2 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1103868/+subscriptions
