On Tue, Apr 27, 2010 at 04:16:24PM -0600, Eric Blake wrote:
On 04/27/2010 01:34 PM, Daniel P. Berrange wrote:
Some applications need to be able to query a guest's disk info, even for paths not managed by the storage pool APIs. This adds a very simple API to get this information, modelled on the virStorageVolGetInfo API, but with an extra field 'physical'. Normally 'physical' and 'allocation' will be identical, but in the case of a qcow2-like file stored inside a block device 'physical' will give the block device size, while 'allocation' will give the qcow2 image size
ACK, and thanks for the examples in the comments.
+ * - Fully allocated raw file in filesystem: + * * capacity, allocation, physical: All the same
Actually, might it be possible that allocation/physical might be slightly higher than capacity, to account for inode overhead and rounding up to block size? But I don't see the need to clutter this documentation with that level of detail.
Yeah, there's a tiny difference, but if you squint with your eyes they are the same :-P Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|