Red Hat Bugzilla – Bug 888008
RFE: qemu-img should be able to report the amount of space used by a qcow2 image stored on a block device
Last modified: 2015-02-25 08:11:39 EST
Description of problem: qemu-img should be able to report the amount of space used by a qcow2 image on a block device. Version-Release number of selected component (if applicable): qemu-img-0.12.1.2-2.295.el6_3.4.x86_64 Steps to Reproduce: # vgcreate testvg01 /dev/mapper/1IET_00010001 # lvcreate -n lvtest01 -L 1G testvg01 # qemu-img create -f qcow2 /dev/testvg01/lvtest01 20G Formatting '/dev/testvg01/lvtest01', fmt=qcow2 size=21474836480 encryption=off cluster_size=65536 # qemu-img info /dev/testvg01/lvtest01 image: /dev/testvg01/lvtest01 file format: qcow2 virtual size: 20G (21474836480 bytes) disk size: 0 cluster_size: 65536 Actual results: There is no command reporting how much space of /dev/testvg01/lvtest01 is in use by the qcow2 image. Expected results: qemu-img should provide a way to report the amount of space used. Additional info: A patch has been proposed upstream: http://lists.gnu.org/archive/html/qemu-devel/2012-12/msg01153.html which provides such functionality through the "check" command: # qemu-img check /dev/testvg01/lvtest01 No errors were found on the image. Highest offset in use: 262144
This request was not resolved in time for the current release. Red Hat invites you to ask your support representative to propose this request, if still desired, for consideration in the next release of Red Hat Enterprise Linux.
Discuss with kwolf in IRC that 'Highest offset in use' has been renamed to 'Image end offset' during patch review. And i did not reproduce this issue with qemu-kvm-360 and qemu-kvm-355, both of them were ok. kwolf said that he git checkout qemu-kvm-0.12.1.2-2.360.el6. Verify this issue on qemu-kvm-0.12.1.2-2.376.el6.x86_64. host info: # uname -r && rpm -q qemu-kvm 2.6.32-392.el6.x86_64 qemu-kvm-0.12.1.2-2.376.el6.x86_64 Steps and results: 1.create a lvm. # pvcreate /dev/sdb Physical volume "/dev/sdb" successfully created # vgcreate vg-90.100-sluo /dev/sdb Volume group "vg-90.100-sluo" successfully created # lvcreate -L 20G -n lv-90-100-sluo /dev/vg-90.100-sluo Logical volume "lv-90-100-sluo" created 2.create qcow2 to the lvm. # qemu-img create -f qcow2 /dev/vg-90.100-sluo/lv-90-100-sluo 20G Formatting '/dev/vg-90.100-sluo/lv-90-100-sluo', fmt=qcow2 size=21474836480 encryption=off cluster_size=65536 lazy_refcounts=off 3.check the image info. # qemu-img info /dev/vg-90.100-sluo/lv-90-100-sluo image: /dev/vg-90.100-sluo/lv-90-100-sluo file format: qcow2 virtual size: 20G (21474836480 bytes) disk size: 0 cluster_size: 65536 # qemu-img check /dev/vg-90.100-sluo/lv-90-100-sluo No errors were found on the image. Image end offset: 262144 4.check if it's there with --output=json # qemu-img check /dev/vg-90.100-sluo/lv-90-100-sluo --output=json { "image-end-offset": 262144, "total-clusters": 327680, "check-errors": 0, "filename": "/dev/vg-90.100-sluo/lv-90-100-sluo", "format": "qcow2" } Base on above, this issue has been fixed correctly, set verified status. please correct me if any mistake. Best Regards, sluo
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHSA-2013-1553.html