From: Tomas Vondra <tv@fuzzy.cz>
To: Lucas Mocellin <lucasmocellin@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: PostgreSQL perform poorly on VMware ESXi
Date: Mon, 7 Nov 2011 11:54:02 +0100
Message-ID: <c56c4518ff0622adb27deaf29417fd77.squirrel@sq.gransy.com> (raw)
In-Reply-To: <CAFsUHaZysBW4qBfEdQkuYJY7wJ0Z_oQi9WFwANebGcP=G7poFg@mail.gmail.com>
References: <CAFsUHaZysBW4qBfEdQkuYJY7wJ0Z_oQi9WFwANebGcP=G7poFg@mail.gmail.com>
On 7 Listopad 2011, 11:36, Lucas Mocellin wrote:
> Hi everybody,
>
> I'm having some issues with PostgreSQL 9.03 running on FreeBSD 8.2 on top
> of VMware ESXi 4.1 U1.
>
> The problem is query are taking too long, and some times one query
> "blocks"
> everybody else to use the DB as well.
>
> I'm a network administrator, not a DBA, so many things here can be
> "newbie"
> for you guys, so please be patient. :)
>
> Clonning this database to another machine not virtualized, any "crap"
> machine, it runs a way fastar, I've measured one specific "SELECT" and at
> the virtualized system (4GB RAM, 4 processors, SATA disk, virtualized), it
> took 15minutes!, in the crap machine (2GB RAM, 1 processor, SATA disk, NOT
> virtualized), it took only 2!!!
What is this "cloning" thing? Dump/restore? Something at the
filesystem-device level?
My wild guess is that the autovacuum is not working, thus the database is
bloated and the cloning removes the bloat.
Post EXPLAIN ANALYZE output of the query for both machines (use
explain.depesz.com).
Have you done any benchmarking on the virtualized machine to check the
basic I/O performance? A simple "dd test", bonnie?
Tomas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: tv@fuzzy.cz, lucasmocellin@gmail.com
Subject: Re: PostgreSQL perform poorly on VMware ESXi
In-Reply-To: <c56c4518ff0622adb27deaf29417fd77.squirrel@sq.gransy.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox