9.0-RELEASE success

[Matt Connor]

On 2012-01-19 18:18, Michael MacLeod wrote:
> On Thu, Jan 19, 2012 at 9:06 PM, Matt Connor <bsd at xerq.net [5]> 
> wrote:
>
>> On 2012-01-19 15 [3]:19, Xin Li wrote:
>>
>>> -----BEGIN PGP SIGNED MESSAGE-----
>>> Hash: SHA1
>>>
>>> On 01/19/12 13:22, Matt Connor wrote:
>>>
>>>> On 19.01.2012 13:15, Nick Sayer wrote:
>>>>
>>>>> I have a VPS at rootbsd.net [1], and have been running
>>>>> 8.2-RELEASE
>>>>> with a XENHVM kernel with a patch to fix the do something
>>>>> smart
>>>>> panic in if_xn. I fetched the 9.0-RELEASE source tree and
>>>>> built a
>>>>> kernel to try and it worked without any muss or fuss. I did
>>>>> the
>>>>> rest of the upgrade and its working just fine, so far as I
>>>>> can
>>>>> tell.
>>>>>
>>>>> And there was much
>>>>> rejoicing._______________________________________________
>>>>
>>>> Same here at ssdnodes.com [2] - we pulled the new source tree,
>>>> rebuilt
>>>> with our modified XENHVM and havent had any issues so far.
>>>>
>>>> We had many tweaks in /etc/sysctl.conf to improve throughput
>>>> for
>>>> the 8.2-RELEASE, the 9.0-RELEASE systems still remained snappy
>>>> after the tweaks were removed.
>>>
>>> What kinds of tweaks are needed?  (i.e. should we make them the
>>> defaults?)
>>
>> The tweaks were only "needed" because we were trying to achieve a
>> specific network throughput in our particular workload (read:
>> turning the knob all the way until it broke off). These values are
>> no longer in production on version 9.0-RELEASE, I highly recommend
>> these never become default.
>>
>> For your amusement, Ive included the values below:
>>
>> <<<...SNIP...>>>
>
> Any of these recommended for those of us who arent rushing to leave
> 8.2 yet?
>
> Links:
> ------
> [1] http://rootbsd.net
> [2] http://ssdnodes.com


It honestly depends on what you're trying to accomplish, I can't give 
any blanket advice that will cover all the various workloads. Ours in 
particular was serving a combination of many small image files and a few 
large files that were being constantly hit between 150-300Mbps. After a 
month or two of benchmarking, we found these values to help 
considerably.

If your workload is similar (or you're feeling particularly sadistic 
today), I would suggest doing rigorous benchmarks on your current 
system, then changing the sysctl values one-by-one and making note of 
the changes in performance. Unfortunately you cannot do the same with 
the /boot/loader.conf values (these actually require a reboot).