NFS server bottlenecks

[Ivan Voras]

On 20 October 2012 13:42, Nikolay Denev <ndenev at gmail.com> wrote:

> Here are the results from testing both patches : http://home.totalterror.net/freebsd/nfstest/results.html
> Both tests ran for about 14 hours ( a bit too much, but I wanted to compare different zfs recordsize settings ),
> and were done first after a fresh reboot.
> The only noticeable difference seems to be much more context switches with Ivan's patch.

Thank you very much for your extensive testing!

I don't know how to interpret the rise in context switches; as this is
kernel code, I'd expect no context switches. I hope someone else can
explain.

But, you have also shown that my patch doesn't do any better than
Rick's even on a fairly large configuration, so I don't think there's
value in adding the extra complexity, and Rick knows NFS much better
than I do.

But there are a few things other than that I'm interested in: like why
does your load average spike almost to 20-ties, and how come that with
24 drives in RAID-10 you only push through 600 MBit/s through the 10
GBit/s Ethernet. Have you tested your drive setup locally (AESNI
shouldn't be a bottleneck, you should be able to encrypt well into
Gbyte/s range) and the network?

If you have the time, could you repeat the tests but with a recent
Samba server and a CIFS mount on the client side? This is probably not
important, but I'm just curious of how would it perform on your
machine.