diff options
| author | John Snow <jsnow@redhat.com> | 2017-07-17 20:34:22 -0400 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2017-07-18 15:27:37 +0200 |
| commit | 6e6e55f5c2e5b520d6506c2716287ba3b5d1bbc8 (patch) | |
| tree | ed30613055c350d84000cd205b35bd6ffc441054 /qemu-img.texi | |
| parent | 2a32c6e82ed24d837ce7af346ffc93113f0164b5 (diff) | |
qemu-img: Check for backing image if specified during create
Or, rather, force the open of a backing image if one was specified
for creation. Using a similar -unsafe option as rebase, allow qemu-img
to ignore the backing file validation if possible.
It may not always be possible, as in the existing case when a filesize
for the new image was not specified.
This is accomplished by shifting around the conditionals in
bdrv_img_create, such that a backing file is always opened unless we
provide BDRV_O_NO_BACKING. qemu-img is adjusted to pass this new flag
when -u is provided to create.
Sorry for the heinous looking diffstat, but it's mostly whitespace.
Inspired by: https://bugzilla.redhat.com/show_bug.cgi?id=1213786
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'qemu-img.texi')
| -rw-r--r-- | qemu-img.texi | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/qemu-img.texi b/qemu-img.texi index f11f6036ad..72dabd6b3e 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -233,7 +233,7 @@ If @code{-r} is specified, exit codes representing the image state refer to the state after (the attempt at) repairing it. That is, a successful @code{-r all} will yield the exit code 0, independently of the image state before. -@item create [-f @var{fmt}] [-b @var{backing_file}] [-F @var{backing_fmt}] [-o @var{options}] @var{filename} [@var{size}] +@item create [-f @var{fmt}] [-b @var{backing_file}] [-F @var{backing_fmt}] [-u] [-o @var{options}] @var{filename} [@var{size}] Create the new disk image @var{filename} of size @var{size} and format @var{fmt}. Depending on the file format, you can add one or more @var{options} @@ -244,6 +244,13 @@ only the differences from @var{backing_file}. No size needs to be specified in this case. @var{backing_file} will never be modified unless you use the @code{commit} monitor command (or qemu-img commit). +Note that a given backing file will be opened to check that it is valid. Use +the @code{-u} option to enable unsafe backing file mode, which means that the +image will be created even if the associated backing file cannot be opened. A +matching backing file must be created or additional options be used to make the +backing file specification valid when you want to use an image created this +way. + 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. |