Alan, On 11/23/05 2:00 PM, "Alan Stange" <stange@xxxxxxxxxx> wrote: > Luke Lonergan wrote: >> Why not contribute something - put up proof of your stated 8KB versus >> 32KB page size improvement. > > I did observe that 32KB block sizes were a significant win "for our > usage patterns". It might be a win for any of the following reasons: > (* big snip *) Though all of what you relate is interesting, it seems irrelevant to your earlier statement here: >> Alan Stange <stange@xxxxxxxxxx> writes: >> If your goal is sequential IO, then one must use larger block sizes. >> No one would use 8KB IO for achieving high sequential IO rates. Simply >> put, read() is about the slowest way to get 8KB of data. Switching >> to 32KB blocks reduces all the system call overhead by a large margin. >> Larger blocks would be better still, up to the stripe size of your >> mirror. (Of course, you're using a mirror and not raid5 if you care >> about performance.) And I am interested in seeing if your statement is correct. Do you have any proof of this to share? - Luke
