Re: Data write speed - Mailing list pgsql-performance

From Josh Berkus
Subject Re: Data write speed
Date
Msg-id web-2846264@davinci.ethosmedia.com
Whole thread Raw
In response to Re: Data write speed  (Kevin Brown <kevin@sysexperts.com>)
Responses Re: Data write speed
List pgsql-performance
Kevin,

> That does seem low.  What rate do you get with software RAID (of the
> same type, of course) to the same disks (might have to be through a
> standard SCSI controller to be meaningful) with roughly the same
> disks/channel distribution?

Unfortunately, I can't do this without blowing away all of my current
software setup.   I noticed the performance problem *after* installing
Linux, PostgreSQL, Apache, PHP, pam_auth, NIS, and my database ....
and, of course, customized builds of the above.

> The Adaptec 2200S has a 100MHz CPU.  That's pretty weak.  The typical
> modern desktop system has a factor of 20 more CPU power than that.  A
> software RAID setup would have no trouble blowing the 2200S out of
> the
> water, especially if the OS is able to make use of features such as
> tagged queueing.
>
> Since the 2200S has a JBOD mode, you might consider testing a
> software
> RAID setup across that, just to see how much of a difference doing
> the
> RAID calculations on the host system makes.

This isn't something I can do without blowing away my current software
setup, hey?

-Josh

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