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path: root/docs/specs/qcow2.txt
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2012-05-02docs: fix one issue in qcow2 specsZhi Yong Wu
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20Specification for qcow2 version 3Kevin Wolf
This updates the qcow2 specification to cover version 3. It contains the following changes: - Added compatible/incompatible/auto-clear feature bits plus an optional feature name table to allow useful error messages even if an older version doesn't know some feature at all. - Configurable refcount width. If you don't want to use internal snapshots, make refcounts one bit and save cache space and I/O. - Zero cluster flags. This allows discard even with a backing file that doesn't contain zeros. It is also useful for copy-on-read/image streaming, as you'll want to keep sparseness without accessing the remote image for an unallocated cluster all the time. - Fixed internal snapshot metadata to use 64 bit VM state size. You can't save a snapshot of a VM with >= 4 GB RAM today. - Extended internal snapshot metadata to contain the disk size, so that resizing images that have snapshots can be allowed in the future. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15qcow2: Allow >4 GB VM stateKevin Wolf
This is a compatible extension to the snapshot header format that allows saving a 64 bit VM state size. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28qcow2: fix some errors and typo in qcow2.txtZhi Yong Wu
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-03-16Add qcow2 documentationKevin Wolf
This adds a description of the qcow2 file format to the docs/ directory. Besides documenting what's there, which is never wrong, the document should provide a good basis for the discussion of format extensions (called "qcow3" in previous discussions) Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>