Dominik Klein wrote:
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.
Yes, you are right.
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.
how about the start Guest with option "cache=none" to bypass pagecache? This should help i think.
Did your tests show something different? Maybe I did things wrong then.
I think blkio cgroup should work if "cache=none" is set. But I didn't try it, Will try it later. Thanks Gui
Regards Dominik
-- Regards Gui Jianfeng