Re: Need help with postgresql/apache/php optimisation - Mailing list pgsql-general

From scott.marlowe
Subject Re: Need help with postgresql/apache/php optimisation
Date
Msg-id Pine.LNX.4.33.0402181337160.3215-100000@css120.ihs.com
Whole thread Raw
In response to Need help with postgresql/apache/php optimisation  ("Froggy / Froggy Corp." <froggy@froggycorp.com>)
List pgsql-general
On Wed, 18 Feb 2004, Froggy / Froggy Corp. wrote:

>     The problem is that on "fire time", the load go to > 1 and stay long
> time. But with top (i use top -d 1 to have "real" load average) i can
> see that the CPU is more than 50% idling.
>
> For exemple, i have this kind of stat :
>
> 0s - load 1.5 - cpu idling 0%
> 5s - load 1.6 - cpu ilding 50%
> 6s -> 60s - load around 1.2 - cpu idling around 50%-100%

sounds to me like you're starving for bandwidth on your I/O subsystem.
any chance you can get a faster set of drives under it or go with a SCSI
RAID controller with battery backed cache?

also, turning off fsync may increase speed at the cost of data security in
the event of a kernel crash or power failure.

Are you doing a lot of writing or mostly just reading?  If mostly reading,
then you might do well with more memory in the machine.  256 meg is kinda
puny.  You'd do better with my old PIII750 machine that had 1.5 gig in it
than a celeron with only 256 meg, no matter how fast the celeron.


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