docs/interop/prl-xml.rst: Fix minor grammar nits

Fix some minor grammar nits in the prl-xml documentation.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20240801170131.3977807-6-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2024-08-09 17:37:55 +01:00
parent 7d9fc7e74d
commit 09334420d2
1 changed files with 39 additions and 34 deletions

View File

@ -13,15 +13,15 @@ Parallels Disk Format
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
which is enough to properly work with QEMU. Nevertheless, Parallels Cloud Server
and Parallels Desktop are able to add some unspecified nodes to the 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.
uses auxiliary xml ``Snapshot.xml``, which allows storage of optional snapshot
information, but this doesn't influence open/read/write functionality. QEMU and
other software should not use fields not covered in this document or the
``Snapshot.xml`` file, and must leave them as is.
Parallels disk consists of two parts: the set of snapshots and the disk
A Parallels disk consists of two parts: the set of snapshots and the disk
descriptor file, which stores information about all files and snapshots.
Definitions
@ -29,7 +29,7 @@ Definitions
Snapshot
a record of the contents captured at a particular time, capable
of storing current state. A snapshot has UUID and parent UUID.
of storing current state. A snapshot has a UUID and a parent UUID.
Snapshot image
an overlay representing the difference between this
@ -39,13 +39,13 @@ Overlay
an image storing the different sectors between two captured states.
Root image
snapshot image with no parent, the root of snapshot tree.
a snapshot image with no parent, the root of the 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
covers a 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
@ -55,7 +55,7 @@ Storage
Description file
``DiskDescriptor.xml`` stores information about disk parameters,
snapshots, storages.
snapshots, and storages.
Top Snapshot
The overlay between actual state and some previous snapshot.
@ -70,9 +70,9 @@ 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``.
The element has only one attribute, ``Version``, which must be ``1.0``.
Schema of ``DiskDescriptor.xml``::
The schema of ``DiskDescriptor.xml``::
<Parallels_disk_image Version="1.0">
<Disk_Parameters>
@ -100,11 +100,11 @@ The ``Disk_Parameters`` element MUST contain the following child elements:
* ``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``
Limitation: The 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
use padding set to 1; however this case is not covered
by this specification. QEMU and other software should not open
such disks and should not create them.
``StorageData`` element
@ -121,20 +121,20 @@ as shown below::
</Storage>
</StorageData>
A ``Storage`` element has following child elements:
A ``Storage`` element has the 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
The cluster size for each "Compressed" (see below) image in
a parallels disk must be equal to this field. Note: the cluster
size for a Parallels Expandable Image is in the ``tracks`` field of
its header (see :doc:`parallels`).
* Several ``Image`` child elements.
Each ``Image`` element has following child elements:
Each ``Image`` element has the following child elements:
* ``GUID`` - image identifier, UUID in curly brackets.
For instance, ``{12345678-9abc-def1-2345-6789abcdef12}.``
@ -145,7 +145,7 @@ Each ``Image`` element has following child elements:
* ``Plain`` for raw files.
* ``Compressed`` for expanding disks.
* ``File`` - path to image file. Path can be relative to
* ``File`` - path to image file. The path can be relative to
``DiskDescriptor.xml`` or absolute.
``Snapshots`` element
@ -171,17 +171,22 @@ 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
The software may traverse snapshots from child to parent using the
``<ParentGUID>`` field as reference. The ``ParentGUID`` of the root
snapshot is ``{00000000-0000-0000-0000-000000000000}``.
There should be only one root snapshot.
The Top snapshot could be
described via two ways: via the ``TopGUID`` child
element of the ``Snapshots`` element, or via the 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,
the predefined GUID is interpreted as a normal GUID. All snapshot images
(except the 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.
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. The Top snapshot cannot have this GUID.