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authorMiroslav Rezanina <mrezanin@redhat.com>2013-02-13 09:09:41 +0100
committerKevin Wolf <kwolf@redhat.com>2013-02-22 21:21:10 +0100
commitd14ed18c8d10a936e6f8b55f56afb4b75c305e10 (patch)
tree36f8fbe4ad74ab8f3d2bd89510d17eb7cd6d6945 /qemu-img.texi
parentf382d43a9180ed20c671dc058d5452c2df7d3c61 (diff)
downloadqemu-arm-d14ed18c8d10a936e6f8b55f56afb4b75c305e10.tar.gz
qemu-img: Add compare subcommand
This patch adds new qemu-img subcommand that compares content of two disk images. Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'qemu-img.texi')
-rw-r--r--qemu-img.texi53
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}