[libvirt] [PATCH 0/6 v3] Add blkio cgroup support

[Dominik Klein]

> Hmm.. "blkio.weight" is used to control the Minimal Maximal Bandwidth. If you'd like
> to control Max bandwidth to let your guests become I/O hungery. "blkio.throttle.*"
> should helps. But these tunables aren't supported by blkiotune for the time being.
> I'm considering to implement them in the future.

Hm, maybe I was not clear then. Let me try to rephrase.

As far as I understand, and as far as I saw during my tests, the blkio
controller only works for sync I/O requests (eg dd with oflag=direct).
Buffered I/O is not part of the control.

And since a VM's I/O is most likely buffered in some fashion, this does
not have any effect. That's what my tests showed.

Did your tests show something different? Maybe I did things wrong then.

Regards
Dominik