Re: [Qemu-devel] [PATCH 2/2] block: qemu-iotests for vhdx, read sample dynamic imagee

[Kevin Wolf]

Am 20.09.2013 um 11:10 hat Alex Bennée geschrieben:
> 
> address@hidden writes:
> 
> > This adds the VHDX format to the qemu-iotests format, and adds
> > a read test.  The test reads from an existing sample image, that
> > was created with Hyper-V under Windwos Server 2012.
> >
> > The image file is a 1GB dynamic image, with 32MB blocks.
> >
> > The pattern 0xa5 exists from 0MB-33MB (past a block size boundary)
> >
> > The pattern 0x96 exists from 33MB-66MB (past another block boundary,
> > and leaving a partial blank block)
> >
> > From 66MB-1024MB, all reads should return 0.
> >
> > Although 1GB dynamic image with 66MB of data, the bzip2'ed image
> > file size is only 874 bytes.
> 
> I take it there is additional meta-data in there generated by Windows
> Server itself? Otherwise I would be tempted to write a tool to generate
> the image on demand so it could be used to trigger other edge cases when
> found.
> 
> Having said that 874 bytes certainly isn't to heavy a burden for the
> repository ;-)

Eventually, qemu-img will be able to create VHDX images, but I think the
point is that we compare against real Hyper-V VHDX images to ensure that
we're really reading the spec the same way as they do.

> I'm currently pondering what the best way of supporting system images
> (i.e. kernel+rootfs) would be to make system regression testing easier.
> Unfortunately those images would be far too large to carry in the repo
> although there may be some sub-module annex type thing I could try.

Sounds like you're looking for qemu-tests?

    http://git.qemu.org/?p=qemu-test.git;a=summary

Kevin