[libvirt] [PATCH TCK] Add a test for QCow2 files with a backing store

Daniel P. Berrange berrange at redhat.com
Wed Apr 28 15:46:43 UTC 2010


On Wed, Apr 28, 2010 at 09:42:49AM -0600, Eric Blake wrote:
> On 04/28/2010 09:31 AM, Daniel P. Berrange wrote:
> > diff --git a/scripts/qemu/150-disk-backingstore.t b/scripts/qemu/150-disk-backingstore.t
> > new file mode 100644
> > index 0000000..62d8faf
> > --- /dev/null
> > +++ b/scripts/qemu/150-disk-backingstore.t
> > @@ -0,0 +1,97 @@
> > +# -*- perl -*-
> > +#
> > +# Copyright (C) 2009-2010 Red Hat, Inc.
> 
> Just 2010 is sufficient.

This was a 90% code derivative from another test case so I
left the original copyright date.

> > +
> > +The test case validates that a guest can be booted from a
> > +qcow2 file with a backing store pointing to a physical disk.
> > +This verifies that SELinux labelling, uid/gid changes and
> 
> s/labelling/labeling/
> 
> > +    diag "Creating pool $poolXML";
> > +    lives_ok(sub { $pool = $conn->create_storage_pool($poolXML) }, "pool created");
> > +
> > +
> > +    my $volXML = Sys::Virt::TCK::StorageVolBuilder->new(name => "demo.qcow2")
> > +	->capacity(1024*1024*1024)
> > +	->format("qcow2")
> > +	->backing_store($dev)
> > +	->as_xml();
> 
> That 1GB capacity at odds with the statement in conf/default.cfg that
> block devices need only be 512 MB.  Can we get by with a smaller qcow
> image here, or does the config file minimum size limit need to be
> raised?  Also, it would still be nice to follow through with the idea
> that host_block_devices in the config file list both device name and
> size, to avoid unintentionally trashing the wrong device.

The 512 MB in the config refers to actual disk usage. The 1 GB here is 
the logical qcow2 image size. The actual usage for this will be a few 
10's of KB only, since qcow2 is a grow-on-demand format.


Regards,
Daniel
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