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1 @example |
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2 @c man begin SYNOPSIS |
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3 usage: qemu-img command [command options] |
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4 @c man end |
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5 @end example |
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6 |
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7 @c man begin OPTIONS |
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8 |
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9 The following commands are supported: |
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10 @table @option |
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11 @item create [-e] [-6] [-b @var{base_image}] [-f @var{fmt}] @var{filename} [@var{size}] |
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12 @item commit [-f @var{fmt}] @var{filename} |
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13 @item convert [-c] [-e] [-6] [-f @var{fmt}] [-O @var{output_fmt}] [-B @var{output_base_image}] @var{filename} [@var{filename2} [...]] @var{output_filename} |
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14 @item info [-f @var{fmt}] @var{filename} |
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15 @end table |
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16 |
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17 Command parameters: |
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18 @table @var |
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19 @item filename |
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20 is a disk image filename |
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21 @item base_image |
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22 is the read-only disk image which is used as base for a copy on |
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23 write image; the copy on write image only stores the modified data |
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24 @item output_base_image |
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25 forces the output image to be created as a copy on write |
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26 image of the specified base image; @code{output_base_image} should have the same |
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27 content as the input's base image, however the path, image format, etc may |
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28 differ |
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29 @item fmt |
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30 is the disk image format. It is guessed automatically in most cases. The following formats are supported: |
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31 |
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32 @table @code |
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33 @item raw |
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34 |
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35 Raw disk image format (default). This format has the advantage of |
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36 being simple and easily exportable to all other emulators. If your |
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37 file system supports @emph{holes} (for example in ext2 or ext3 on |
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38 Linux or NTFS on Windows), then only the written sectors will reserve |
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39 space. Use @code{qemu-img info} to know the real size used by the |
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40 image or @code{ls -ls} on Unix/Linux. |
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41 |
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42 @item qcow2 |
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43 QEMU image format, the most versatile format. Use it to have smaller |
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44 images (useful if your filesystem does not supports holes, for example |
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45 on Windows), optional AES encryption, zlib based compression and |
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46 support of multiple VM snapshots. |
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47 @item qcow |
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48 Old QEMU image format. Left for compatibility. |
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49 @item cow |
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50 User Mode Linux Copy On Write image format. Used to be the only growable |
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51 image format in QEMU. It is supported only for compatibility with |
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52 previous versions. It does not work on win32. |
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53 @item vmdk |
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54 VMware 3 and 4 compatible image format. |
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55 @item cloop |
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56 Linux Compressed Loop image, useful only to reuse directly compressed |
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57 CD-ROM images present for example in the Knoppix CD-ROMs. |
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58 @end table |
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59 |
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60 @item size |
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61 is the disk image size in kilobytes. Optional suffixes @code{M} |
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62 (megabyte) and @code{G} (gigabyte) are supported |
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63 |
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64 @item output_filename |
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65 is the destination disk image filename |
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66 |
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67 @item output_fmt |
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68 is the destination format |
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69 |
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70 @item -c |
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71 indicates that target image must be compressed (qcow format only) |
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72 @item -e |
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73 indicates that the target image must be encrypted (qcow format only) |
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74 @item -6 |
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75 indicates that the target image must use compatibility level 6 (vmdk format only) |
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76 @end table |
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77 |
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78 Command description: |
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79 |
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80 @table @option |
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81 @item create [-6] [-e] [-b @var{base_image}] [-f @var{fmt}] @var{filename} [@var{size}] |
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82 |
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83 Create the new disk image @var{filename} of size @var{size} and format |
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84 @var{fmt}. |
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85 |
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86 If @var{base_image} is specified, then the image will record only the |
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87 differences from @var{base_image}. No size needs to be specified in |
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88 this case. @var{base_image} will never be modified unless you use the |
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89 @code{commit} monitor command. |
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90 |
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91 @item commit [-f @var{fmt}] @var{filename} |
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92 |
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93 Commit the changes recorded in @var{filename} in its base image. |
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94 |
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95 @item convert [-c] [-e] [-f @var{fmt}] @var{filename} [-O @var{output_fmt}] @var{output_filename} |
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96 |
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97 Convert the disk image @var{filename} to disk image @var{output_filename} |
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98 using format @var{output_fmt}. It can be optionally encrypted |
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99 (@code{-e} option) or compressed (@code{-c} option). |
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100 |
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101 Only the format @code{qcow} supports encryption or compression. The |
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102 compression is read-only. It means that if a compressed sector is |
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103 rewritten, then it is rewritten as uncompressed data. |
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104 |
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105 Encryption uses the AES format which is very secure (128 bit keys). Use |
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106 a long password (16 characters) to get maximum protection. |
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107 |
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108 Image conversion is also useful to get smaller image when using a |
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109 growable format such as @code{qcow} or @code{cow}: the empty sectors |
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110 are detected and suppressed from the destination image. |
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111 |
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112 @item info [-f @var{fmt}] @var{filename} |
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113 |
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114 Give information about the disk image @var{filename}. Use it in |
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115 particular to know the size reserved on disk which can be different |
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116 from the displayed size. If VM snapshots are stored in the disk image, |
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117 they are displayed too. |
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118 @end table |
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119 |
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120 @c man end |
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121 |
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122 @ignore |
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123 |
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124 @setfilename qemu-img |
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125 @settitle QEMU disk image utility |
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126 |
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127 @c man begin SEEALSO |
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128 The HTML documentation of QEMU for more precise information and Linux |
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129 user mode emulator invocation. |
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130 @c man end |
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131 |
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132 @c man begin AUTHOR |
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133 Fabrice Bellard |
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134 @c man end |
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135 |
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136 @end ignore |