Am 06.12.2010 17:07, schrieb Stefan Hajnoczi: > For a changelog against v5, see below. > > QEMU Enhanced Disk format is a disk image format that forgoes features > found in qcow2 in favor of better levels of performance and data > integrity. Due to its simpler on-disk layout, it is possible to safely > perform metadata updates more efficiently. > > Installations, suspend-to-disk, and other allocation-heavy I/O workloads > will see increased performance due to fewer I/Os and syncs. Workloads > that do not cause new clusters to be allocated will perform similar to > raw images due to in-memory metadata caching. > > The format supports sparse disk images. It does not rely on the host > filesystem holes feature, making it a good choice for sparse disk images > that need to be transferred over channels where holes are not supported. > > Backing files are supported so only deltas against a base image can be > stored. The base image may be smaller than the image file. > > The file format is extensible so that additional features can be added > later with graceful compatibility handling. A specification for the file > format is included in this patchset. > > Internal snapshots are not supported. This eliminates the need for > additional metadata to track copy-on-write clusters. > > Compression and encryption are not supported. They add complexity and can be > implemented at other layers in the stack (i.e. inside the guest or on the > host). Encryption has been identified as a potential future extension and the > file format allows for this. > > Signed-off-by: Anthony Liguori <aligu...@us.ibm.com> > Signed-off-by: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com>
Thanks, reluctantly applied to the block branch. ;-) Kevin