Re: [libvirt-users] data monitored by "virDomainBlockStats" API not consistent with ones reading from /proc/[pid]/io, and corrugated with /proc/diskstats

On 06/25/2014 05:11 AM, coperd wrote: [please don't top-post on technical lists] Bear in mind that for some file formats, such as qcow2, qemu must read (and write) additional I/O to manage the metadata of the file in comparison to the amount of read and writes performed on behalf of the guest; the qemu numbers are reported from the guest perspective, not what qemu asked the host kernel to do. So seeing /proc/NN/io have larger numbers than qemu makes total sense. I'm still not clear how you are getting vcpu PID numbers for reading from /proc; it's not something that libvirt is currently advertising. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org