Patchwork [v7,4/4] Add qemu-img compare documentation

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Submitter Miroslav Rezanina
Date Dec. 17, 2012, 1:39 p.m.
Message ID <1355751593-31535-5-git-send-email-mrezanin@redhat.com>
Download mbox | patch
Permalink /patch/206873/
State New
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Comments

Miroslav Rezanina - Dec. 17, 2012, 1:39 p.m.
From: Miroslav Rezanina <mrezanin@redhat.com>

Adding documentation for new qemu-img subcommand compare.

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 qemu-img.c    |  7 ++++++-
 qemu-img.texi | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)
Eric Blake - Dec. 19, 2012, 6:15 p.m.
On 12/17/2012 06:39 AM, mrezanin@redhat.com wrote:
> From: Miroslav Rezanina <mrezanin@redhat.com>
> 
> Adding documentation for new qemu-img subcommand compare.
> 
> Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
> ---
>  qemu-img.c    |  7 ++++++-
>  qemu-img.texi | 32 ++++++++++++++++++++++++++++++++
>  2 files changed, 38 insertions(+), 1 deletion(-)
> 
> diff --git a/qemu-img.c b/qemu-img.c
> index 8b4f01f..a185e9e 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -103,7 +103,12 @@ static void help(void)
>             "  '-a' applies a snapshot (revert disk to saved state)\n"
>             "  '-c' creates a snapshot\n"
>             "  '-d' deletes a snapshot\n"
> -           "  '-l' lists all snapshots in the given image\n";
> +           "  '-l' lists all snapshots in the given image\n"
> +           "\n"
> +           "Parameters to compare subcommand:\n"
> +           "  '-f' First image format\n"
> +           "  '-F' Second image format\n"
> +           "  '-s' Strict mode - fail on different image size or sector allocation\n";

s/First/first/; s/Second/second/; s/Strict/strict/ for consistent
appearance of starting description with lower case

>  @table @option
> @@ -117,6 +129,26 @@ 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.

Wrap this long line.
Miroslav Rezanina - Dec. 20, 2012, 7:46 p.m.
----- Original Message -----
> From: "Eric Blake" <eblake@redhat.com>
> To: mrezanin@redhat.com
> Cc: qemu-devel@nongnu.org, kwolf@redhat.com, pbonzini@redhat.com, stefanha@redhat.com
> Sent: Wednesday, December 19, 2012 7:15:11 PM
> Subject: Re: [Qemu-devel] [PATCH v7 4/4] Add qemu-img compare documentation
> 
> On 12/17/2012 06:39 AM, mrezanin@redhat.com wrote:
> > From: Miroslav Rezanina <mrezanin@redhat.com>
> > 
> > Adding documentation for new qemu-img subcommand compare.
> > 
> > Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
> > ---
> >  qemu-img.c    |  7 ++++++-
> >  qemu-img.texi | 32 ++++++++++++++++++++++++++++++++
> >  2 files changed, 38 insertions(+), 1 deletion(-)
> > 
> > diff --git a/qemu-img.c b/qemu-img.c
> > index 8b4f01f..a185e9e 100644
> > --- a/qemu-img.c
> > +++ b/qemu-img.c
> > @@ -103,7 +103,12 @@ static void help(void)
> >             "  '-a' applies a snapshot (revert disk to saved
> >             state)\n"
> >             "  '-c' creates a snapshot\n"
> >             "  '-d' deletes a snapshot\n"
> > -           "  '-l' lists all snapshots in the given image\n";
> > +           "  '-l' lists all snapshots in the given image\n"
> > +           "\n"
> > +           "Parameters to compare subcommand:\n"
> > +           "  '-f' First image format\n"
> > +           "  '-F' Second image format\n"
> > +           "  '-s' Strict mode - fail on different image size or
> > sector allocation\n";
> 
> s/First/first/; s/Second/second/; s/Strict/strict/ for consistent
> appearance of starting description with lower case

Yes for First and Second, but Strict mode is same case as Quiet mode
in patch 02 - it's always capital S not because it's start of description.

> 
> >  @table @option
> > @@ -117,6 +129,26 @@ 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.
> 
> Wrap this long line.

None of the long lines is wraped in qemu-img.c in this part of code so I did not wrap it intentionally. 
> 
> --
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
> 
> 
Miroslav Rezanina

Patch

diff --git a/qemu-img.c b/qemu-img.c
index 8b4f01f..a185e9e 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -103,7 +103,12 @@  static void help(void)
            "  '-a' applies a snapshot (revert disk to saved state)\n"
            "  '-c' creates a snapshot\n"
            "  '-d' deletes a snapshot\n"
-           "  '-l' lists all snapshots in the given image\n";
+           "  '-l' lists all snapshots in the given image\n"
+           "\n"
+           "Parameters to compare subcommand:\n"
+           "  '-f' First image format\n"
+           "  '-F' Second image format\n"
+           "  '-s' Strict mode - fail on different image size or sector allocation\n";
 
     printf("%s\nSupported formats:", help_msg);
     bdrv_iterate_format(format_print, NULL);
diff --git a/qemu-img.texi b/qemu-img.texi
index bb82a3d..7eb1934 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
@@ -117,6 +129,26 @@  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.
+
 @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}