Re: High CPU usage / load average after upgrading to Ubuntu 12.04

On 02/14/2013 08:47 PM, Scott Marlowe wrote:
> If you run your benchmarks for more than a few minutes I highly
> recommend enabling sysstat service data collection, then you can look
> at it after the fact with sar.  VERY useful stuff both for
> benchmarking and post mortem on live servers.

Well, background sar, by default on Linux, only collects every 30min.
For a benchmark run, you want to generate your own sar file, for example:

sar -o hddrun2.sar -A 10 90 &

which says "collect all stats every 10 seconds and write them to the
file hddrun2.sar for 15 minutes"


-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com