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| author | Max Reitz <mreitz@redhat.com> | 2014-10-24 15:57:40 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-11-03 11:41:48 +0000 |
| commit | 1b22bffd829ee3db4ddcfbd7e66c7a7921123f3e (patch) | |
| tree | 101b205f2b3bfe9fa3f8a9d1dc801f7799ba4fca /qemu-img.texi | |
| parent | 687fa1d83013d56f7c7f9c008c956f4c26d8ba5c (diff) | |
qemu-img: Specify backing file for commit
Introduce a new parameter for qemu-img commit which may be used to
explicitly specify the backing file into which an image should be
committed if the backing chain has more than a single layer.
[Applied Eric Blake's qemu-img.texi documentation rewording
--Stefan]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1414159063-25977-12-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'qemu-img.texi')
| -rw-r--r-- | qemu-img.texi | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/qemu-img.texi b/qemu-img.texi index f82d1b4923..078851adb6 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -167,7 +167,7 @@ this case. @var{backing_file} will never be modified unless you use the The size can also be specified using the @var{size} option with @code{-o}, it doesn't need to be specified separately in this case. -@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-d] [-p] @var{filename} +@item commit [-q] [-f @var{fmt}] [-t @var{cache}] [-b @var{base}] [-d] [-p] @var{filename} Commit the changes recorded in @var{filename} in its base image or backing file. If the backing file is smaller than the snapshot, then the backing file will be @@ -180,6 +180,16 @@ The image @var{filename} is emptied after the operation has succeeded. If you do not need @var{filename} afterwards and intend to drop it, you may skip emptying @var{filename} by specifying the @code{-d} flag. +If the backing chain of the given image file @var{filename} has more than one +layer, the backing file into which the changes will be committed may be +specified as @var{base} (which has to be part of @var{filename}'s backing +chain). If @var{base} is not specified, the immediate backing file of the top +image (which is @var{filename}) will be used. For reasons of consistency, +explicitly specifying @var{base} will always imply @code{-d} (since emptying an +image after committing to an indirect backing file would lead to different data +being read from the image due to content in the intermediate backing chain +overruling the commit target). + @item compare [-f @var{fmt}] [-F @var{fmt}] [-T @var{src_cache}] [-p] [-s] [-q] @var{filename1} @var{filename2} Check if two images have the same content. You can compare images with |