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@example
@c man begin SYNOPSIS
usage: qemu-img command [command options]
@c man end
@end example
@c man begin OPTIONS
The following commands are supported:
@include qemu-img-cmds.texi
Command parameters:
@table @var
@item filename
is a disk image filename
@item fmt
is the disk image format. It is guessed automatically in most cases. See below
for a description of the supported disk formats.
@item size
is the disk image size in bytes. Optional suffixes @code{k} or @code{K}
(kilobyte, 1024) @code{M} (megabyte, 1024k) and @code{G} (gigabyte, 1024M)
and T (terabyte, 1024G) are supported. @code{b} is ignored.
@item output_filename
is the destination disk image filename
@item output_fmt
is the destination format
@item options
is a comma separated list of format specific options in a
name=value format. Use @code{-o ?} for an overview of the options supported
by the used format
@item -c
indicates that target image must be compressed (qcow format only)
@item -h
with or without a command shows help and lists the supported formats
@end table
Parameters to snapshot subcommand:
@table @option
@item snapshot
is the name of the snapshot to create, apply or delete
@item -a
applies a snapshot (revert disk to saved state)
@item -c
creates a snapshot
@item -d
deletes a snapshot
@item -l
lists all snapshots in the given image
@end table
Command description:
@table @option
@item create [-f @var{fmt}] [-o @var{options}] @var{filename} [@var{size}]
Create the new disk image @var{filename} of size @var{size} and format
@var{fmt}. Depending on the file format, you can add one or more @var{options}
that enable additional features of this format.
If the option @var{backing_file} is specified, then the image will record
only the differences from @var{backing_file}. No size needs to be specified in
this case. @var{backing_file} will never be modified unless you use the
@code{commit} monitor command (or qemu-img commit).
The size can also be specified using the @var{size} option with @code{-o},
it doesn't need to be specified separately in this case.
@item commit [-f @var{fmt}] @var{filename}
Commit the changes recorded in @var{filename} in its base image.
@item convert [-c] [-f @var{fmt}] [-O @var{output_fmt}] [-o @var{options}] @var{filename} [@var{filename2} [...]] @var{output_filename}
Convert the disk image @var{filename} to disk image @var{output_filename}
using format @var{output_fmt}. It can be optionally compressed (@code{-c}
option) or use any format specific options like encryption (@code{-o} option).
Only the formats @code{qcow} and @code{qcow2} support compression. The
compression is read-only. It means that if a compressed sector is
rewritten, then it is rewritten as uncompressed data.
Image conversion is also useful to get smaller image when using a
growable format such as @code{qcow} or @code{cow}: the empty sectors
are detected and suppressed from the destination image.
You can use the @var{backing_file} option to force the output image to be
created as a copy on write image of the specified base image; the
@var{backing_file} should have the same content as the input's base image,
however the path, image format, etc may differ.
@item info [-f @var{fmt}] @var{filename}
Give information about the disk image @var{filename}. Use it in
particular to know the size reserved on disk which can be different
from the displayed size. If VM snapshots are stored in the disk image,
they are displayed too.
@item snapshot [-l | -a @var{snapshot} | -c @var{snapshot} | -d @var{snapshot} ] @var{filename}
List, apply, create or delete snapshots in image @var{filename}.
@end table
Supported image file formats:
@table @option
@item raw
Raw disk image format (default). This format has the advantage of
being simple and easily exportable to all other emulators. If your
file system supports @emph{holes} (for example in ext2 or ext3 on
Linux or NTFS on Windows), then only the written sectors will reserve
space. Use @code{qemu-img info} to know the real size used by the
image or @code{ls -ls} on Unix/Linux.
@item host_device
Host device format. This format should be used instead of raw when
converting to block devices or other devices where "holes" are not
supported.
@item qcow2
QEMU image format, the most versatile format. Use it to have smaller
images (useful if your filesystem does not supports holes, for example
on Windows), optional AES encryption, zlib based compression and
support of multiple VM snapshots.
Encryption uses the AES format which is very secure (128 bit keys). Use
a long password (16 characters) to get maximum protection.
@item qcow
Old QEMU image format. Left for compatibility.
@item cow
User Mode Linux Copy On Write image format. Used to be the only growable
image format in QEMU. It is supported only for compatibility with
previous versions. It does not work on win32.
@item vdi
VirtualBox 1.1 compatible image format.
@item vmdk
VMware 3 and 4 compatible image format.
@item cloop
Linux Compressed Loop image, useful only to reuse directly compressed
CD-ROM images present for example in the Knoppix CD-ROMs.
@end table
@c man end
@ignore
@setfilename qemu-img
@settitle QEMU disk image utility
@c man begin SEEALSO
The HTML documentation of QEMU for more precise information and Linux
user mode emulator invocation.
@c man end
@c man begin AUTHOR
Fabrice Bellard
@c man end
@end ignore
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