[libvirt] [PATCH 0/6 v3] Add blkio cgroup support
Dominik Klein
dk at in-telegence.net
Fri Feb 18 09:08:30 UTC 2011
>> 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.
whew :)
>> 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.
I will read up on where to set that and give it a try. Thanks for the hint.
>>
>> 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.
Please let us know what you found out during your tests.
Regards
Dominik
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