qemu-img.texi

   1 @example
   2 @c man begin SYNOPSIS
   3 usage: qemu-img command [command options]
   4 @c man end
   5 @end example
   6
   7 @c man begin OPTIONS
   8
   9 The following commands are supported:
  10
  11 @include qemu-img-cmds.texi
  12
  13 Command parameters:
  14 @table @var
  15 @item filename
  16  is a disk image filename
  17 @item fmt
  18 is the disk image format. It is guessed automatically in most cases. See below
  19 for a description of the supported disk formats.
  20
  21 @item size
  22 is the disk image size in bytes. Optional suffixes @code{k} or @code{K}
  23 (kilobyte, 1024) @code{M} (megabyte, 1024k) and @code{G} (gigabyte, 1024M)
  24 and T (terabyte, 1024G) are supported.  @code{b} is ignored.
  25
  26 @item output_filename
  27 is the destination disk image filename
  28
  29 @item output_fmt
  30  is the destination format
  31 @item options
  32 is a comma separated list of format specific options in a
  33 name=value format. Use @code{-o ?} for an overview of the options supported
  34 by the used format
  35
  36
  37 @item -c
  38 indicates that target image must be compressed (qcow format only)
  39 @item -h
  40 with or without a command shows help and lists the supported formats
  41 @end table
  42
  43 Parameters to snapshot subcommand:
  44
  45 @table @option
  46
  47 @item snapshot
  48 is the name of the snapshot to create, apply or delete
  49 @item -a
  50 applies a snapshot (revert disk to saved state)
  51 @item -c
  52 creates a snapshot
  53 @item -d
  54 deletes a snapshot
  55 @item -l
  56 lists all snapshots in the given image
  57 @end table
  58
  59 Command description:
  60
  61 @table @option
  62 @item create [-f @var{fmt}] [-o @var{options}] @var{filename} [@var{size}]
  63
  64 Create the new disk image @var{filename} of size @var{size} and format
  65 @var{fmt}. Depending on the file format, you can add one or more @var{options}
  66 that enable additional features of this format.
  67
  68 If the option @var{backing_file} is specified, then the image will record
  69 only the differences from @var{backing_file}. No size needs to be specified in
  70 this case. @var{backing_file} will never be modified unless you use the
  71 @code{commit} monitor command (or qemu-img commit).
  72
  73 The size can also be specified using the @var{size} option with @code{-o},
  74 it doesn't need to be specified separately in this case.
  75
  76 @item commit [-f @var{fmt}] @var{filename}
  77
  78 Commit the changes recorded in @var{filename} in its base image.
  79
  80 @item convert [-c] [-f @var{fmt}] [-O @var{output_fmt}] [-o @var{options}] @var{filename} [@var{filename2} [...]] @var{output_filename}
  81
  82 Convert the disk image @var{filename} to disk image @var{output_filename}
  83 using format @var{output_fmt}. It can be optionally compressed (@code{-c}
  84 option) or use any format specific options like encryption (@code{-o} option).
  85
  86 Only the formats @code{qcow} and @code{qcow2} support compression. The
  87 compression is read-only. It means that if a compressed sector is
  88 rewritten, then it is rewritten as uncompressed data.
  89
  90 Image conversion is also useful to get smaller image when using a
  91 growable format such as @code{qcow} or @code{cow}: the empty sectors
  92 are detected and suppressed from the destination image.
  93
  94 You can use the @var{backing_file} option to force the output image to be
  95 created as a copy on write image of the specified base image; the
  96 @var{backing_file} should have the same content as the input's base image,
  97 however the path, image format, etc may differ.
  98
  99 @item info [-f @var{fmt}] @var{filename}
 100
 101 Give information about the disk image @var{filename}. Use it in
 102 particular to know the size reserved on disk which can be different
 103 from the displayed size. If VM snapshots are stored in the disk image,
 104 they are displayed too.
 105
 106 @item snapshot [-l | -a @var{snapshot} | -c @var{snapshot} | -d @var{snapshot} ] @var{filename}
 107
 108 List, apply, create or delete snapshots in image @var{filename}.
 109 @end table
 110
 111 Supported image file formats:
 112
 113 @table @option
 114 @item raw
 115
 116 Raw disk image format (default). This format has the advantage of
 117 being simple and easily exportable to all other emulators. If your
 118 file system supports @emph{holes} (for example in ext2 or ext3 on
 119 Linux or NTFS on Windows), then only the written sectors will reserve
 120 space. Use @code{qemu-img info} to know the real size used by the
 121 image or @code{ls -ls} on Unix/Linux.
 122
 123 @item host_device
 124
 125 Host device format. This format should be used instead of raw when
 126 converting to block devices or other devices where "holes" are not
 127 supported.
 128
 129 @item qcow2
 130 QEMU image format, the most versatile format. Use it to have smaller
 131 images (useful if your filesystem does not supports holes, for example
 132 on Windows), optional AES encryption, zlib based compression and
 133 support of multiple VM snapshots.
 134
 135 Encryption uses the AES format which is very secure (128 bit keys). Use
 136 a long password (16 characters) to get maximum protection.
 137 @item qcow
 138 Old QEMU image format. Left for compatibility.
 139 @item cow
 140 User Mode Linux Copy On Write image format. Used to be the only growable
 141 image format in QEMU. It is supported only for compatibility with
 142 previous versions. It does not work on win32.
 143 @item vdi
 144 VirtualBox 1.1 compatible image format.
 145 @item vmdk
 146 VMware 3 and 4 compatible image format.
 147 @item cloop
 148 Linux Compressed Loop image, useful only to reuse directly compressed
 149 CD-ROM images present for example in the Knoppix CD-ROMs.
 150 @end table
 151
 152
 153 @c man end
 154
 155 @ignore
 156
 157 @setfilename qemu-img
 158 @settitle QEMU disk image utility
 159
 160 @c man begin SEEALSO
 161 The HTML documentation of QEMU for more precise information and Linux
 162 user mode emulator invocation.
 163 @c man end
 164
 165 @c man begin AUTHOR
 166 Fabrice Bellard
 167 @c man end
 168
 169 @end ignore