Extensibility to tackle current and future storage virtualization challenges.Fully QCOW2 backwards-compatible feature set.Near-raw performance, competitive with QED.Version number should be used (and therefore, which features should be So it's an option to continue letting users know the format as "qcow2", just with anĪdditional flag that can be set on image creation and specifies which
Internally, QEMU will have a single driver for both QCOW2 and QCOW3 images, Unchanged, so that a single codebase will be enough for working with Strictly an extension of QCOW2 and keeps the fundamental structure Increase in order to introduce some incompatible features, however it's The proposal for QCOW3 is different: It includes a version number Implementations and the two versions actually are exposed as twoĭifferent image formats ("qcow" and "qcow2") to the user. QCOW1 and QCOW2 have two completely different driver When this version number was changed from QCOW1 to QCOW2, the format was Qemu versions can't read the image any more. The QCOW image format includes a version number to allow introducing newįeatures that change the format in an incompatible way, so that older qemu-img amend can be used to upgrade or downgrade existing images. A compatibility level of 1.1 means that the new format is in use. qemu-img info displays the compatibility level of an image. When creating images, use the -o compat= option to create an image in the non-default format version. The proposed image format change was introduced in QEMU 1.1 and became the default for image creation with QEMU 1.7. This page is mostly of historical interest.
#QEMU IMG CREATE QCOW2 UPDATE#