On Tuesday August 16, djani22@xxxxxxxxxxxxx wrote: > Hello list, > > I have performance problem. (again) :-) > > What chunk size is better in raid5, and raid0? > The lot of small chunks, or some bigger? This is highly dependant one workload and hardware performance. The best thing to do is develop a test that simulates your real workload and run it with various stripe sizes, and see which one wins. I suspect there would be very little gain in going to very small chunk sizes (<16k). Anywhere between there and 1Meg is worth trying. mdadm uses a default of 64k which is probably not too bad for most situations, but I cannot promise it being optimal for any. Sorry I cannot be more helpful. Your performance problem may not be chunk-size related. Maybe increasing the readahead (with blockdev) would help... NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
