Re: Block size recommendation for Red Hat Linux 7.2

Thanks Scott.
Please suggest the OS block sizes for Linux redhat 7.2, where as default
Linux block size is 4k.

If we keep 8k block size at OS level is it improves PostgreSQL performance?
Please suggest what is the suggestible default OS block size for Linux
systems to install PostgreSQL.

Thanks,
Chiru

On Mon, Apr 24, 2017 at 12:29 PM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>
wrote:

> On Mon, Apr 24, 2017 at 9:41 AM, chiru r <chirupg(at)gmail(dot)com> wrote:
> > Hello,
> >
> > I am building new server to run PostgreSQL 9.5.4 version on it. Please
> > provide the recommended Block size for Linux systems.
> >
> > We are using PostgreSQL blocks size is 8k default one.
> >
> > postgres=# show block_size ;
> > block_size
> > ------------
> > 8192
> > (1 row)
> >
> > Is there any recommendation for separate block sizes on OS level for
> > Pg_xlog, pg_log and Actual data files to improve the performance for
> > reads/Writes?.
>
> Unless you've done some testing to show some other block size is
> better, it's best to stick to 8k block size. Keep in mind that while
> it is configurable at compile time, it doesn't get much testing at
> other sizes and you could run into corner cases where there are
> problems and the only acceptable fix is to compile with 8k blocks and
> reload your whole db etc.
>
> tl;dr: Stick to 8k blocks.
>
> --
> To understand recursion, one must first understand recursion.
>