Re: Block size recommendation for Red Hat Linux 7.2

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.

--
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