High rate of NFS cache misses after upgrading from 10.3-prerelease to 11.1-release

[Eugene Grosbein]

15.04.2018 19:58, Rick Macklem wrote:

> Niels Kobschaetzki wrote:
> [stuff snipped]
>> It is a website with quite some traffic handles by three webservers behind a pair >of loadbalancers.
>> We see a loss of 20% in speed(TTFB reduced by 100ms; sounds not a lot but >Google et al doesn’t like it at all) after upgrading to 11.1 with a combined upgrade >to php7.1. On another server without NFS that upgrade improved performance >considerably (I was told ca 30% by the front end-dev)
> One thing you could try is booting the 11.1 kernel on an 10.3 system. Newer
> FreeBSD kernels should work with older userland.

Though one should remember that some important system utilities
may and probably will not work with newer kernel, like /sbin/ipfw, route,
ifconfig, netstat etc.

> This would tell you if it is kernel changes or userland changes that are causing
> the higher miss rate.