[Libvir] Reopening the old discussion about virDomainBlockPeek

Virt-df[1] has now gained the ability to fully parse LVM2 partitions, thus: # virt-df -c qemu:///system -h Filesystem Size Used Available Type rhel51x32kvm:hda1 96.8 MiB 14.6 MiB 82.2 MiB Linux ext2/3 rhel51x32kvm:VolGroup00/LogVol00 6.4 GiB 3.6 GiB 2.8 GiB Linux ext2/3 rhel51x32kvm:VolGroup00/LogVol01 992.0 MiB Linux swap However it still has to do it by opening the local partitions / files, which means it isn't using a "proper" part of libvirt and more importantly it cannot run remotely. I'd like to find out whether the time has come for us to look again at a virDomainBlockPeek call for libvirt. Here is the original thread plus patch from 7 months ago: http://www.redhat.com/archives/libvir-list/2007-October/thread.html#00089 (I've attached an updated patch against current CVS). I appreciate that some cases might not be simple (iSCSI?), but the same argument applies to block device statistics too, and we make those available where possible. I think a best-effort call allowing callers to peek into the block devices of guests would be very useful. Rich. [1] http://hg.et.redhat.com/applications/virt/applications/virt-df--devel -- Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://et.redhat.com/~rjones/virt-top