On 12/16/2014 08:11 AM, Peter Krempa wrote:
On 12/16/14 09:04, Eric Blake wrote:
This patch introduces access to allocation information about a backing chain of a live domain. While querying storage volumes for read-only disks could provide some of the details, there is one case where we have to rely on qemu: when doing a block commit into a backing file, where that file is stored in qcow2 format on a host block device, we want to know the current highest write offset into that image, in order to know if the disk must be resized larger. qemu-img does not (currently) show this information, and none of the earlier block APIs were extensible enough to expose it. But virDomainListGetStats is perfect for the job!
* block device. + * "block.<num>.backingIndex" - unsigned int giving the <backingStore> index, + * when backing images are listed.
You add the field to this help, but ...
-I<--block> returns: +I<--block> returns information about disks associated with each +domain. Using the I<--backing> flag extends this information to +cover all resources in the backing chain, rather than the default +of limiting information to the active layer for each guest disk. +Information listed includes: "block.count" - number of block devices on this domain, "block.<num>.name" - name of the target of the block device <num>, "block.<num>.path" - file source of block device <num>, if it is a
... not to the manpage.
ACK with ^^.
Fixed and pushed. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org