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diff --git a/docs/interop/prl-xml.txt b/docs/interop/prl-xml.txt deleted file mode 100644 index cf9b3fba26..0000000000 --- a/docs/interop/prl-xml.txt +++ /dev/null @@ -1,158 +0,0 @@ -= License = - -Copyright (c) 2015-2017, Virtuozzo, Inc. -Authors: - 2015 Denis Lunev <den@openvz.org> - 2015 Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> - 2016-2017 Klim Kireev <klim.kireev@virtuozzo.com> - 2016-2017 Edgar Kaziakhmedov <edgar.kaziakhmedov@virtuozzo.com> - -This work is licensed under the terms of the GNU GPL, version 2 or later. -See the COPYING file in the top-level directory. - -This specification contains minimal information about Parallels Disk Format, -which is enough to proper work with QEMU. Nevertheless, Parallels Cloud Server -and Parallels Desktop are able to add some unspecified nodes to xml and use -them, but they are for internal work and don't affect functionality. Also it -uses auxiliary xml "Snapshot.xml", which allows to store optional snapshot -information, but it doesn't influence open/read/write functionality. QEMU and -other software should not use fields not covered in this document and -Snapshot.xml file and must leave them as is. - -= Parallels Disk Format = - -Parallels disk consists of two parts: the set of snapshots and the disk -descriptor file, which stores information about all files and snapshots. - -== Definitions == - Snapshot a record of the contents captured at a particular time, - capable of storing current state. A snapshot has UUID and - parent UUID. - - Snapshot image an overlay representing the difference between this - snapshot and some earlier snapshot. - - Overlay an image storing the different sectors between two captured - states. - - Root image snapshot image with no parent, the root of snapshot tree. - - Storage the backing storage for a subset of the virtual disk. When - there is more than one storage in a Parallels disk then that - is referred to as a split image. In this case every storage - covers specific address space area of the disk and has its - particular root image. Split images are not considered here - and are not supported. Each storage consists of disk - parameters and a list of images. The list of images always - contains a root image and may also contain overlays. The - root image can be an expandable Parallels image file or - plain. Overlays must be expandable. - - Description DiskDescriptor.xml stores information about disk parameters, - file snapshots, storages. - - Top The overlay between actual state and some previous snapshot. - Snapshot It is not a snapshot in the classical sense because it - serves as the active image that the guest writes to. - - Sector a 512-byte data chunk. - -== Description file == -All information is placed in a single XML element Parallels_disk_image. -The element has only one attribute "Version", that must be 1.0. -Schema of DiskDescriptor.xml: - -<Parallels_disk_image Version="1.0"> - <Disk_Parameters> - ... - </Disk_Parameters> - <StorageData> - ... - </StorageData> - <Snapshots> - ... - </Snapshots> -</Parallels_disk_image> - -== Disk_Parameters element == -The Disk_Parameters element describes the physical layout of the virtual disk -and some general settings. - -The Disk_Parameters element MUST contain the following child elements: - * Disk_size - number of sectors in the disk, - desired size of the disk. - * Cylinders - number of the disk cylinders. - * Heads - number of the disk heads. - * Sectors - number of the disk sectors per cylinder - (sector size is 512 bytes) - Limitation: Product of the Heads, Sectors and Cylinders - values MUST be equal to the value of the Disk_size parameter. - * Padding - must be 0. Parallels Cloud Server and Parallels Desktop may - use padding set to 1, however this case is not covered - by this spec, QEMU and other software should not open - such disks and should not create them. - -== StorageData element == -This element of the file describes the root image and all snapshot images. - -The StorageData element consists of the Storage child element, as shown below: -<StorageData> - <Storage> - ... - </Storage> -</StorageData> - -A Storage element has following child elements: - * Start - start sector of the storage, in case of non split storage - equals to 0. - * End - number of sector following the last sector, in case of non - split storage equals to Disk_size. - * Blocksize - storage cluster size, number of sectors per one cluster. - Cluster size for each "Compressed" (see below) image in - parallels disk must be equal to this field. Note: cluster - size for Parallels Expandable Image is in 'tracks' field of - its header (see docs/interop/parallels.txt). - * Several Image child elements. - -Each Image element has following child elements: - * GUID - image identifier, UUID in curly brackets. - For instance, {12345678-9abc-def1-2345-6789abcdef12}. - The GUID is used by the Snapshots element to reference images - (see below) - * Type - image type of the element. It can be: - "Plain" for raw files. - "Compressed" for expanding disks. - * File - path to image file. Path can be relative to DiskDescriptor.xml or - absolute. - -== Snapshots element == -The Snapshots element describes the snapshot relations with the snapshot tree. - -The element contains the set of Shot child elements, as shown below: -<Snapshots> - <TopGUID> ... </TopGUID> /* Optional child element */ - <Shot> - ... - </Shot> - <Shot> - ... - </Shot> - ... -</Snapshots> - -Each Shot element contains the following child elements: - * GUID - an image GUID. - * ParentGUID - GUID of the image of the parent snapshot. - -The software may traverse snapshots from child to parent using <ParentGUID> -field as reference. ParentGUID of root snapshot is -{00000000-0000-0000-0000-000000000000}. There should be only one root -snapshot. Top snapshot could be described via two ways: via TopGUID child -element of the Snapshots element or via predefined GUID -{5fbaabe3-6958-40ff-92a7-860e329aab41}. If TopGUID is defined, predefined GUID is -interpreted as usual GUID. All snapshot images (except Top Snapshot) should be -opened read-only. There is another predefined GUID, -BackupID = {704718e1-2314-44c8-9087-d78ed36b0f4e}, which is used by original and -some third-party software for backup, QEMU and other software may operate with -images with GUID = BackupID as usual, however, it is not recommended to use this -GUID for new disks. Top snapshot cannot have this GUID. |