On Mon, Oct 8, 2012 at 6:10 AM, Steve Dickson <SteveD@xxxxxxxxxx> wrote: > On 05/10/12 13:57, Quentin Barnes wrote: [...] >> Since for our work, for other reasons, we've switched over to >> using NFSv3 TCP mounts, so I can't justify spending a lot of time >> debugging this UDP/RPC problem. However, for example if someone >> wants me to try something out and gather some new test results or >> a patch to test, I can squeeze that in. [...] > > I think there probably has been a steady decline in UPD performance > over the years. In my data, after the initial big hit between RHEL4 and RHEL5, NFSv3/UDP performance went back up peaking with 2.6.31, then declined with 2.6.32 and RHEL6, and has then held steady ever since. Now I have seen a significant dip my NFSv3/TCP performance data after 3.3 with 3.6 (I don't have data points for 3.4 & 3.5), but didn't want to get into that here and I hadn't looked into it hard enough yet to verify it. > The main reason is that nobody uses it since TCP is a > much better transport to use with NFS... I disagree somewhat, at least for my particular configuration and networks. With my testing and tuning with FreeBSD and 2.6.9 and earlier Linux kernels, NFSv3/UDP overall performance is generally 10%-15% better than NFSv3/TCP. > Why are you still using UDP as your transport? We're not. See my above quoted paragraph. I still measure and monitor NFSv3/UDP's performance as part of my kernel development work improving the kernel's NFS performance for our needs, but since no one uses UDP mounts in house currently, I can't justify the time to find and fix the bug. > steved. Quentin -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
