[ovirt-users] Re: qemu-img info showed iscsi/FC lun size 0

On Fri, Feb 22, 2019 at 5:00 PM Jingjie Jiang <jingjie.jiang(a)oracle.com&gt; wrote: > What about qcow2 format? > qcow2 reports the real size regardless of the underlying storage, since

> Not for LUNs, only for images. The available formats in 4.3 are documented here: https://ovirt.org/develop/release-management/features/storage/incremental... incremental means you checked the checkbox "Enable incremental backup" when creating a disk. But note that the fact that we will create qcow2 image is implementation detail and the behavior may change in the future. For example, qemu is expected to provide a way to do incremental backup with raw volumes, and in this case we may create a raw volume instead of qcow2 volume. (actually raw data volume and qcow2 metadata volume). If you want to control the disk format, the only way is via the REST API or SDK, where you can specify the format instead of allocation policy. However even if you specify the format in the SDK the system may chose to change the format when copying the disk to another storage type. For example if you copy qcow2/sparse image from block storage to file storage the system will create a raw/sparse image. If you desire to control the format both from the UI and REST API/SDK and ensure that the system will never change the selected format please file a bug explaining the use case. On 2/21/19 5:46 PM, Nir Soffer wrote: > > > > On Thu, Feb 21, 2019, 21:48 <jingjie.jiang(a)oracle.com wrote: > >> Hi, >> Based on oVirt 4.3.0, I have data domain from FC lun, then I create new >> vm on the disk from FC data domain. >> After VM was created. According to qemu-img info, the disk size is 0. >> # qemu-img info >> /rhev/data-center/mnt/blockSD/eaa6f641-6b36-4c1d-bf99-6ba77df3156f/images/8d3b455b-1da4-49f3-ba57-8cda64aa9dc9/949fa315-3934-4038-85f2-08aec52c1e2b >> >> image: >> /rhev/data-center/mnt/blockSD/eaa6f641-6b36-4c1d-bf99-6ba77df3156f/images/8d3b455b-1da4-49f3-ba57-8cda64aa9dc9/949fa315-3934-4038-85f2-08aec52c1e2b >> file format: raw >> virtual size: 10G (10737418240 bytes) >> disk size: 0 >> >> I tried on iscsi and same result. >> >> Is the behaviour expected? >> > > It is expected in a way. Disk size is the amount of storage actually > used, and block devices has no way to tell that. > > oVirt report the size of the block device in this case, which is more > accurate than zero. > > However the real size allocated on the undrelying storage is somewhere > between zero an device size, and depends on the imlementation of the > storage. Nither qemu-img nor oVirt can tell the real size. > > Nir > > >> Thanks, >> Jingjie >> >> _______________________________________________ >> Users mailing list -- users(a)ovirt.org >> To unsubscribe send an email to users-leave(a)ovirt.org >> Privacy Statement: https://www.ovirt.org/site/privacy-policy/ >> oVirt Code of Conduct: >> https://www.ovirt.org/community/about/community-guidelines/ >> List Archives: >> https://lists.ovirt.org/archives/list/users@ovirt.org/message/TSXP7RENWIF... >> >