Re: Best suiting OS - Mailing list pgsql-performance

On 10/01/2009 03:44 PM, 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.

Lots of conflicting opinions and results in this thread. Also, a lot of
hand waving and speculation. :-)

RHEL and CentOS are particular bad *right now*. See here:
     http://en.wikipedia.org/wiki/RHEL
     http://en.wikipedia.org/wiki/CentOS

For RHEL, look down to "Release History" and RHEL 5.3 based on
Linux-2.6.18, released March, 2007. On the CentOS page you'll see it is
dated April, 2007. CentOS is identical to RHEL on purpose, but always 1
to 6 months after the RHEL, since they take the RHEL source, re-build
it, and then re-test it.

Linux is up to Linux-2.6.31.1 right now:
     http://www.kernel.org/

So any comparisons between operating system *distributions* should be
fair. Comparing a 2007 release to a 2009 release, for example, is not
fair. RHEL / CentOS are basically out of the running right now, because
they are so old. However, RHEL 6.0 should be out in January or February,
2010, at which point it will be relevant again.

Personally, I use Fedora, and my servers have been quite stable. One of
our main web servers running Fedora:

[mark@bambi]~% uptime
  09:45:41 up 236 days, 10:07,  1 user,  load average: 0.02, 0.04, 0.08

It was last rebooted as a scheduled reboot, not a crash. This isn't to
say Fedora will be stable for you - however, having used both RHEL and
Fedora, in many different configurations, I find RHEL being 2+ years
behind in terms of being patch-current means that it is NOT as stable on
modern hardware. Most recently, I installed RHEL on a 10 machine cluster
of HP nodes, and RHEL would not detect the SATA controller out of the
box and reverted to some base PIO mode yielding 2 Mbyte/s disk speed.
Fedora was able to achieve 112 Mbyte/s on the same disks. Some twiddling
of grub.conf allowed RHEL to achieve the same speed, but the point is
that there are two ways to de-stabilize a kernel. One is to use the
leading edge, the other is to use the trailing edge. Using an operating
system designed for 2007 on hardware designed in 2009 is a bad idea.
Using an operating system designed for 2009 on 2007 hardware might also
be a bad idea. Using a modern operating system on modern hardware that
the operating system was designed for will give you the best performance
potential. In this case, Fedora 11 with Linux 2.6.30.8 is almost
guaranteed to out-perform RHEL 5.3 with Linux 2.6.18. Where Fedora is
within 1 to 6 months of the leading edge, Ubuntu is within 3 to 9 months
of the leading edge, so Ubuntu will perform more similar to Fedora than
RHEL.

I've given up on the OS war. People use what they are comfortable with.
Comfort lasts until the operating systems screws a person over, at which
point they "hate" it, and switch to something else. It's about passion -
not about actual metrics, capability, reliability, or any of these other
supposed criteria. In my case, I'm comfortable with RedHat, because I've
used it since the '90s, and because I've seen how they hire some of the
best open source developers, and contribute quality releases back to the
community, specifically including our very own Tom Lane and until
recently Alan Cox. Many of their employees have high fame in the open
source / Linux arena. As a result, my passion is for RedHat-based
releases. As I describe earlier, RHEL is too old right now - and I am
looking forward to RHEL 6.0 catching up to the rest of the world again.
I've found Fedora to be a great alternative when I do need to be on the
leading edge.

So - use what you want - but try not to pretend this isn't about
passion. Even between BSD and Linux, I understand they re-use drivers,
or at least knowledge. It's software that runs your computer. If one OS
can give you +2% performance over another for a 3 month period - big
deal - the available hardware can get a lot better than that +2% by
spending a tiny bit more money, or just waiting 3 months. In the case of
RHEL, waiting about 4 months will give you RHEL 6.0 which will be within
3 to 9 months of the leading edge. If you are planning a new deployment
- this might be something to consider. I suggest not going with RHEL 5
at this time...

Cheers,
mark

--
Mark Mielke<mark@mielke.cc>