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Re: High load and iowait but no disk access

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: pgsql-performance(at)postgresql(dot)org
Cc: Rémy Beaumont <remyb(at)medrium(dot)com>
Subject: Re: High load and iowait but no disk access
Date: 2005-08-30 18:32:06
Message-ID: 200508301132.06904.josh@agliodbs.com (view raw or flat)
Thread:
Lists: pgsql-performance
Remy,

> The behavior we see is that when running queries that do random reads
> on disk, IOWAIT goes over 80% and actual disk IO falls to a crawl at a
> throughput bellow 3000kB/s (We usually average 40000 kB/s to 80000 kB/s
> on sequential read operations on the netapps)

This seems pretty low for a NetApp -- you should be able to manage up to 
180mb/s, if not higher.   Are you sure it's configured correctly?

-- 
--Josh

Josh Berkus
Aglio Database Solutions
San Francisco

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