mirror of
https://github.com/qemu/qemu.git
synced 2024-12-06 02:03:38 +08:00
324b2298fe
Apart from targets.rst, which was written by hand, this is an automated conversion obtained with the following command: makeinfo --force -o - --docbook \ -D 'qemu_system_x86 QEMU_SYSTEM_X86_MACRO' \ -D 'qemu_system QEMU_SYSTEM_MACRO' \ $texi | pandoc -f docbook -t rst+smart | perl -e ' $/=undef; $_ = <>; s/^- − /- /gm; s/QEMU_SYSTEM_MACRO/|qemu_system|/g; s/QEMU_SYSTEM_X86_MACRO/|qemu_system_x86|/g; s/(?=::\n\n +\|qemu)/.. parsed-literal/g; s/:\n\n::$/::/gm; print' > $rst In addition, the following changes were made manually: - target-i386.rst and target-mips.rst: replace CPU model documentation with an include directive - monitor.rst: replace the command section with a comment - images.rst: add toctree - target-arm.rst: Replace use of :math: (which Sphinx complains about) with :sup:, and hide it behind |I2C| and |I2C| substitutions. Content that is not @included remains exclusive to qemu-doc.texi. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 20200228153619.9906-20-peter.maydell@linaro.org Message-id: 20200226113034.6741-19-pbonzini@redhat.com [PMM: Fixed target-arm.rst use of :math:; remove out of date note about images.rst from commit message; fixed expansion of |qemu_system_x86|; use parsed-literal in invocation.rst when we want to use |qemu_system_x86|; fix incorrect subsection level for "OS requirements" in target-i386.rst; fix incorrect syntax for making links to other sections of the manual] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
86 lines
3.1 KiB
ReStructuredText
86 lines
3.1 KiB
ReStructuredText
.. _disk_005fimages:
|
|
|
|
Disk Images
|
|
-----------
|
|
|
|
QEMU supports many disk image formats, including growable disk images
|
|
(their size increase as non empty sectors are written), compressed and
|
|
encrypted disk images.
|
|
|
|
.. _disk_005fimages_005fquickstart:
|
|
|
|
Quick start for disk image creation
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
You can create a disk image with the command::
|
|
|
|
qemu-img create myimage.img mysize
|
|
|
|
where myimage.img is the disk image filename and mysize is its size in
|
|
kilobytes. You can add an ``M`` suffix to give the size in megabytes and
|
|
a ``G`` suffix for gigabytes.
|
|
|
|
See the qemu-img invocation documentation for more information.
|
|
|
|
.. _disk_005fimages_005fsnapshot_005fmode:
|
|
|
|
Snapshot mode
|
|
~~~~~~~~~~~~~
|
|
|
|
If you use the option ``-snapshot``, all disk images are considered as
|
|
read only. When sectors in written, they are written in a temporary file
|
|
created in ``/tmp``. You can however force the write back to the raw
|
|
disk images by using the ``commit`` monitor command (or C-a s in the
|
|
serial console).
|
|
|
|
.. _vm_005fsnapshots:
|
|
|
|
VM snapshots
|
|
~~~~~~~~~~~~
|
|
|
|
VM snapshots are snapshots of the complete virtual machine including CPU
|
|
state, RAM, device state and the content of all the writable disks. In
|
|
order to use VM snapshots, you must have at least one non removable and
|
|
writable block device using the ``qcow2`` disk image format. Normally
|
|
this device is the first virtual hard drive.
|
|
|
|
Use the monitor command ``savevm`` to create a new VM snapshot or
|
|
replace an existing one. A human readable name can be assigned to each
|
|
snapshot in addition to its numerical ID.
|
|
|
|
Use ``loadvm`` to restore a VM snapshot and ``delvm`` to remove a VM
|
|
snapshot. ``info snapshots`` lists the available snapshots with their
|
|
associated information::
|
|
|
|
(qemu) info snapshots
|
|
Snapshot devices: hda
|
|
Snapshot list (from hda):
|
|
ID TAG VM SIZE DATE VM CLOCK
|
|
1 start 41M 2006-08-06 12:38:02 00:00:14.954
|
|
2 40M 2006-08-06 12:43:29 00:00:18.633
|
|
3 msys 40M 2006-08-06 12:44:04 00:00:23.514
|
|
|
|
A VM snapshot is made of a VM state info (its size is shown in
|
|
``info snapshots``) and a snapshot of every writable disk image. The VM
|
|
state info is stored in the first ``qcow2`` non removable and writable
|
|
block device. The disk image snapshots are stored in every disk image.
|
|
The size of a snapshot in a disk image is difficult to evaluate and is
|
|
not shown by ``info snapshots`` because the associated disk sectors are
|
|
shared among all the snapshots to save disk space (otherwise each
|
|
snapshot would need a full copy of all the disk images).
|
|
|
|
When using the (unrelated) ``-snapshot`` option
|
|
(:ref:`disk_005fimages_005fsnapshot_005fmode`),
|
|
you can always make VM snapshots, but they are deleted as soon as you
|
|
exit QEMU.
|
|
|
|
VM snapshots currently have the following known limitations:
|
|
|
|
- They cannot cope with removable devices if they are removed or
|
|
inserted after a snapshot is done.
|
|
|
|
- A few device drivers still have incomplete snapshot support so their
|
|
state is not saved or restored properly (in particular USB).
|
|
|
|
.. include:: qemu-block-drivers.rst.inc
|