On 03/22/2010 10:44 AM, Raghavendra G wrote:
As we can see, there is not much difference in Rewrite performance with/without io-cache. Hence if there are writes to the same offsets from which reads have been done, data will always be read from back-end and overhead of io-cache can be significant. In these scenarios io-cache is not recommended. However for other cases, such as mostly read-only operations, performance boost from io-cache can be significant.
Thanks for the follow-up. It certainly lines up with what should hypothetically happen (which is a good thing).
Ultimately what all of these exercises have shown is that performance tuning needs to be done on a per-instance basis, and that there is absolutely no « one size fits all » solution.
-- Daniel Maher <dma+gluster AT witbe DOT net>
