<snip other discussion which i have not addressed>
>
> The disk cache throughput should be measured against network
> throughput, not against some arbitrary ideal. I'd argue that it
> shouldn't be disabling itself based on one bad result either, which is
> what is happening here.
Eventually I will add the network fetch bandwidth measurement, however
as has been discovered it was hard enough to manage this in the
backing store code so I have not done this yet.
However I have changed the disabling test to be scheduled 100 time
quanta in the future when a single write goes slow and then check
against the overall write bandwidth so the low bandwidth writes must
occur over a substantial time period before we disable the cache now
instead of just a single event.
Hope that addresses the "lumpy" nature of writeouts causing spurious
backing store disables.
--
Regards Vincent
http://www.kyllikki.org/
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