diff options
Diffstat (limited to 'qemu-img.texi')
| -rw-r--r-- | qemu-img.texi | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/qemu-img.texi b/qemu-img.texi index 43430fbea1..69f1bda6ae 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -84,6 +84,18 @@ deletes a snapshot lists all snapshots in the given image @end table +Parameters to compare subcommand: + +@table @option + +@item -f +First image format +@item -F +Second image format +@item -s +Strict mode - fail on on different image size or sector allocation +@end table + Command description: @table @option @@ -118,6 +130,47 @@ it doesn't need to be specified separately in this case. Commit the changes recorded in @var{filename} in its base image. +@item compare [-f @var{fmt}] [-F @var{fmt}] [-p] [-s] [-q] @var{filename1} @var{filename2} + +Check if two images have the same content. You can compare images with +different format or settings. + +The format is probed unless you specify it by @var{-f} (used for +@var{filename1}) and/or @var{-F} (used for @var{filename2}) option. + +By default, images with different size are considered identical if the larger +image contains only unallocated and/or zeroed sectors in the area after the end +of the other image. In addition, if any sector is not allocated in one image +and contains only zero bytes in the second one, it is evaluated as equal. You +can use Strict mode by specifying the @var{-s} option. When compare runs in +Strict mode, it fails in case image size differs or a sector is allocated in +one image and is not allocated in the second one. + +By default, compare prints out a result message. This message displays +information that both images are same or the position of the first different +byte. In addition, result message can report different image size in case +Strict mode is used. + +Compare exits with @code{0} in case the images are equal and with @code{1} +in case the images differ. Other exit codes mean an error occurred during +execution and standard error output should contain an error message. +The following table sumarizes all exit codes of the compare subcommand: + +@table @option + +@item 0 +Images are identical +@item 1 +Images differ +@item 2 +Error on opening an image +@item 3 +Error on checking a sector allocation +@item 4 +Error on reading data + +@end table + @item convert [-c] [-p] [-f @var{fmt}] [-t @var{cache}] [-O @var{output_fmt}] [-o @var{options}] [-s @var{snapshot_name}] [-S @var{sparse_size}] @var{filename} [@var{filename2} [...]] @var{output_filename} Convert the disk image @var{filename} or a snapshot @var{snapshot_name} to disk image @var{output_filename} |