drive_mirror crashes on full disk copy of a resized disk with a backing file
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
QEMU |
Fix Released
|
Undecided
|
Vish Ishaya |
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/vishvanan
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/
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/vishvanan
qemu-img resize /home/vishvanan
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
summary: |
- drive_mirror broken on full disk copy of a resized disk with a backing + drive_mirror crashes on full disk copy of a resized disk with a backing file |
Changed in qemu: | |
status: | New → In Progress |
assignee: | nobody → Vish Ishaya (vishvananda) |
separated the final size issue into a separate bug here:
https:/ /bugs.launchpad .net/qemu/ +bug/1103903