Re: [Qemu-devel] is there a limit on the number of in-flight I/O operations?

[Paolo Bonzini]

Il 19/07/2014 00:48, Chris Friesen ha scritto:
>>>
>>
>> I forgot about "-drive ...,iops_max=NNN". :)
> 
> I'm not sure it's actually useful though, since it specifies the max IO
> operations per second, not the maximum number of in-flight operations.

No, that's "-drive iops=NNN".  QEMU implements a leaky bucket algorithm,
where "iops_max" gives the size of the bucket and "iops" gives the
refill rate.

Paolo

> If the far end can't keep up with the requested rate of operations, then
> the number of in-flight operations is going to grow even if you throttle
> the number of operations per second.