Re: Linux vs FreeBSD

On Thu, Apr 3, 2014 at 11:03 PM, François Beausoleil
<francois(at)teksol(dot)info> wrote:
> Hi all!
>
> Does PG perform that much better on FreeBSD? I have some performance issues on a Ubuntu 12.04 which I'd like to resolve. iowait varies a lot, between 5 and 50%. Does FreeBSD better schedule I/O, which could alleviate some of the issues, or not at all? I have no experience administering FreeBSD, but I'm willing to learn if I'll get some performance enhancements out of the switch.
>
> $ uname -a
> Linux munn.ca.seevibes.com 3.2.0-58-generic #88-Ubuntu SMP Tue Dec 3 17:37:58 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

From the research I've done online, this is likely your issue. Kernel
3.2.0 has some issues that directly and severely impact I/O wait times
for PostgreSQL. The suggested fixes (that seem to have worked for
most people reporting in) are to revert the OS to Ubuntu Server 10.04
or to install one of the HWE (HardWare Enablement) kernels into the
12.04 system (this would be one of the kernels from a later release of
Ubuntu provided in the 12.04 repositories).

--
Chris

"If you wish to make an apple pie from scratch, you must first invent
the Universe." -- Carl Sagan