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

Eric Blake
Tue, 24 Jun 2014 19:45:46 -0000

On 06/24/2014 02:24 AM, coperd wrote:

>
> It is supposed that the VM’s disk “rd_bytes" and “wr_bytes"
should
never exceed the value of the physical disk respectively, right ?

That's a question for the qemu folks.

> Doesn’t
> libvirt virDomainBlockStats read disk information from “proc” ?

No, libvirt reads it from the qemu QMP command query-blockstats.  Beyond
that, you'll have to investigate how qemu comes up with that number.


--
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org