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@example |
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@c man begin SYNOPSIS |
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usage: qemu-img command [command options] |
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@c man end |
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@end example |
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|
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@c man begin OPTIONS |
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|
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The following commands are supported: |
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@table @option |
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@item create [-e] [-b @var{base_image}] [-f @var{fmt}] @var{filename} [@var{size}] |
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@item commit [-f @var{fmt}] @var{filename} |
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@item convert [-c] [-e] [-f @var{fmt}] @var{filename} [-O @var{output_fmt}] @var{output_filename} |
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@item info [-f @var{fmt}] @var{filename} |
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@end table |
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|
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Command parameters: |
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@table @var |
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@item filename |
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is a disk image filename |
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@item base_image |
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is the read-only disk image which is used as base for a copy on |
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write image; the copy on write image only stores the modified data |
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|
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@item fmt |
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is the disk image format. It is guessed automatically in most cases. The following formats are supported: |
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|
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@table @code |
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@item raw |
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|
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Raw disk image format (default). This format has the advantage of |
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being simple and easily exportable to all other emulators. If your |
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file system supports @emph{holes} (for example in ext2 or ext3 on |
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Linux or NTFS on Windows), then only the written sectors will reserve |
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space. Use @code{qemu-img info} to know the real size used by the |
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image or @code{ls -ls} on Unix/Linux. |
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|
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@item qcow2 |
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QEMU image format, the most versatile format. Use it to have smaller |
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images (useful if your filesystem does not supports holes, for example |
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on Windows), optional AES encryption, zlib based compression and |
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support of multiple VM snapshots. |
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@item qcow |
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Old QEMU image format. Left for compatibility. |
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@item cow |
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User Mode Linux Copy On Write image format. Used to be the only growable |
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image format in QEMU. It is supported only for compatibility with |
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previous versions. It does not work on win32. |
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@item vmdk |
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VMware 3 and 4 compatible image format. |
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@item cloop |
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Linux Compressed Loop image, useful only to reuse directly compressed |
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CD-ROM images present for example in the Knoppix CD-ROMs. |
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@end table |
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|
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@item size |
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is the disk image size in kilobytes. Optional suffixes @code{M} |
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(megabyte) and @code{G} (gigabyte) are supported |
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|
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@item output_filename |
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is the destination disk image filename |
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|
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@item output_fmt |
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is the destination format |
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|
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@item -c |
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indicates that target image must be compressed (qcow format only) |
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@item -e |
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indicates that the target image must be encrypted (qcow format only) |
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@end table |
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|
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Command description: |
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|
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@table @option |
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@item create [-e] [-b @var{base_image}] [-f @var{fmt}] @var{filename} [@var{size}] |
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|
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Create the new disk image @var{filename} of size @var{size} and format |
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@var{fmt}. |
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|
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If @var{base_image} is specified, then the image will record only the |
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differences from @var{base_image}. No size needs to be specified in |
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this case. @var{base_image} will never be modified unless you use the |
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@code{commit} monitor command. |
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|
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@item commit [-f @var{fmt}] @var{filename} |
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|
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Commit the changes recorded in @var{filename} in its base image. |
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|
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@item convert [-c] [-e] [-f @var{fmt}] @var{filename} [-O @var{output_fmt}] @var{output_filename} |
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|
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Convert the disk image @var{filename} to disk image @var{output_filename} |
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using format @var{output_fmt}. It can be optionnaly encrypted |
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(@code{-e} option) or compressed (@code{-c} option). |
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|
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Only the format @code{qcow} supports encryption or compression. The |
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compression is read-only. It means that if a compressed sector is |
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rewritten, then it is rewritten as uncompressed data. |
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|
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Encryption uses the AES format which is very secure (128 bit keys). Use |
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a long password (16 characters) to get maximum protection. |
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|
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Image conversion is also useful to get smaller image when using a |
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growable format such as @code{qcow} or @code{cow}: the empty sectors |
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are detected and suppressed from the destination image. |
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|
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@item info [-f @var{fmt}] @var{filename} |
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|
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Give information about the disk image @var{filename}. Use it in |
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particular to know the size reserved on disk which can be different |
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from the displayed size. If VM snapshots are stored in the disk image, |
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they are displayed too. |
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@end table |
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|
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@c man end |
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|
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@ignore |
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|
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@setfilename qemu-img |
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@settitle QEMU disk image utility |
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|
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@c man begin SEEALSO |
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The HTML documentation of QEMU for more precise information and Linux |
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user mode emulator invocation. |
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@c man end |
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|
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@c man begin AUTHOR |
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Fabrice Bellard |
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@c man end |
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|
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@end ignore |