On Wed, Aug 09, 2006 at 04:24:55PM -0700, Dave C. Fisk wrote: > Hi Eric, > > Thanks for the information. > > I am aware of the recsize option and its intended use. However, when I > was exploring it to confirm the expected behavior, what I found was the > opposite! > > The test case was build 38, Solaris 11, a 2 GB file, initially created > with 1 MB SW, and a recsize of 8 KB, on a pool with two raid-z 5+1, > accessed with 24 threads of 8 KB RW, for 500,000 ops or 40 seconds which > ever came first. The result at the pool level was 78% of the operations > were RR, all overhead. For the same test, with a 128 KB recsize (the > default), the pool access was pure SW, beautiful.
I'm not sure what RR means, but you should re-try your tests on build 42 or later. Earlier builds have bug 6424554 "full block re-writes need not read data in" which will cause a lot more data to be read than is necessary, when overwriting entire blocks. --matt _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
