Re: Best suiting OS

On 10/3/09 7:35 PM, "Karl Denninger" <karl(at)denninger(dot)net> wrote:

> Denis Lussier wrote:
>> I'm a BSD license fan, but, I don't know much about *BSD otherwise (except
>> that many advocates say it runs PG very nicely).
>>
>>
>>
>> On the Linux side, unless your a dweeb, go with a newer, popular & well
>> supported release for Production. IMHO, that's RHEL 5.x or CentOS 5.x. Of
>> course the latest SLES & UBuntu schtuff are also fine.
>>
>>
>>
>>
>> In other words, unless you've got a really good reason for it, stay away from
>> Fedora & OpenSuse for production usage.
>>
>>
>>
>> On Thu, Oct 1, 2009 at 3:10 PM, <david(at)lang(dot)hm> wrote:
>>
>>> On Thu, 1 Oct 2009, S Arvind wrote:
>>>
>>>
>>>> Hi everyone,
>>>> What is the best Linux flavor for server which runs postgres alone.
>>>> The postgres must handle greater number of database around 200+.
>>>> Performance
>>>> on speed is the vital factor.
>>>> Is it FreeBSD, CentOS, Fedora, Redhat xxx??
>>>>
>>>
>>> as noted by others *BSD is not linux
>>>
>>> among the linux options, the best option is the one that you as a company
>>> are most comfortable with (and have the support/upgrade processes in place
>>> for)
>>>
>>> in general, the newer the kernel the better things will work, but it's far
>>> better to have an 'old' system that your sysadmins understand well and can
>>> support easily than a 'new' system that they don't know well and therefor
>>> have trouble supporting.
>>>
>>> David Lang
>>>
>>
>>
>>
> I am a particular fan of FreeBSD, and in some benchmarking I did between it
> and CentOS FreeBSD 7.x literally wiped the floor with the CentOS release I
> tried on IDENTICAL hardware.
> I also like the 3ware raid coprocessors - they work well, are fast, and I've
> had zero trouble with them.
>
> -- Karl
>

With CentOS 5.x, I have to do quite a bit of tuning to get it to perform
well. I often get almost 2x the performance after tuning.

For I/O --
Deadline scheduler + reasonably large block device read-ahead + XFS
configured with large 'allocsize' settings (8MB to 80MB) make a huge
difference.

Furthermore, the 3ware 35xx and 36xx (I think) I tried performed
particularly badly out of the box without tuning on CentOS.

So, Identical hardware or not, both have to be tuned well to really compare
anyway.

However, I have certainly seen some inefficiencies with Linux and large use
of shared memory -- and I wouldn't be surprised if these problems don't
exist on FreeBSD or OpenSolaris.