Description of problem:
Created a file in the snapshot and committed the changes in the backing file. Disk size of snapshot is unchanged.
Version-Release number of selected component (if applicable):
qemu-kvm-1.5.3-141.el7
How reproducible:
4/4
Steps to Reproduce:
1. Create snapshot and boot the snapshot with below options.
#qemu-img create -f qcow2 -b base.qcow2 sn.qcow2
qemu options:
-device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pci.0,addr=0x3 \
-drive id=drive_image1,if=none,snapshot=off,aio=native,cache=none,format=qcow2,file=/home/testrun/diskfile/sn.qcow2 \
-device scsi-hd,id=image1,drive=drive_image1,bootindex=1 \
2. Create a file in the snapshot
#dd if=/dev/urandom of=sn bs=1M count=2048
#md5sum sn > md5.sn
3. Shutdown the guest and Get the image info of backing file and snapshot
# qemu-img info base.qcow2
image: base.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 3.4G
cluster_size: 65536
Format specific information:
compat: 1.1
lazy refcounts: false
# qemu-img info sn.qcow2
image: sn.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 1.0G ----> 1G
cluster_size: 65536
backing file: base.qcow2
Format specific information:
compat: 1.1
lazy refcounts: false
4. commit the changes.
#qemu-img commit -f qcow2 sn.qcow2
5. Get the image info backing file and snapshot
# qemu-img info base.qcow2
image: base.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 5.4G
cluster_size: 65536
Format specific information:
compat: 1.1
lazy refcounts: false
# qemu-img info sn.qcow2
image: sn.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 1.0G ----> 1G
cluster_size: 65536
backing file: base.qcow2
Format specific information:
compat: 1.1
lazy refcounts: false
Actual results:
Disk size of snapshot is unchanged after commit the changes
Expected results:
Disk size of snapshot should be resized.
Additional info:
Reproduce the issue with qemu-kvm-1.5.3-126.el7 and qemu-kvm-1.5.3-130.el7.
Cannot reproduce the issue with qemu-kvm-rhev-2.9.0-7.el7
# qemu-img info base.qcow2
image: base.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 2.6G
cluster_size: 65536
Format specific information:
compat: 1.1
lazy refcounts: false
refcount bits: 16
corrupt: false
# qemu-img info sn.qcow2
image: sn.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 2.0G ----> 2G
cluster_size: 65536
backing file: base.qcow2
Format specific information:
compat: 1.1
lazy refcounts: false
refcount bits: 16
corrupt: false
# qemu-img commit -f qcow2 sn.qcow2
Image committed.
# qemu-img info base.qcow2
image: base.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 4.6G
cluster_size: 65536
Format specific information:
compat: 1.1
lazy refcounts: false
refcount bits: 16
corrupt: false
# qemu-img info sn.qcow2
image: sn.qcow2
file format: qcow2
virtual size: 20G (21474836480 bytes)
disk size: 256K ----> disk size is resized
cluster_size: 65536
backing file: base.qcow2
Format specific information:
compat: 1.1
lazy refcounts: false
refcount bits: 16
corrupt: false