CERC Performance Question

[Tino Schwarze]

On Wed, Jul 26, 2006 at 03:42:18PM +0200, Florent Gilain wrote:
> Hi all,
> 
> I have many PE1850 and 2800 with Perc4 raid card with 2 RAID 1 Hard disk,
> here is what i get :
> 
> [root at apache1 usr]# date; dd if=/dev/zero of=big_file bs=1024 count=5120000;
> date
> mer jui 26 15:33:31 CEST 2006
> 5120000+0 enregistrements lus.
> 5120000+0 enregistrements écrits.
> mer jui 26 15:35:59 CEST 2006
> [root at apache1 usr]# date; dd of=/dev/zero if=big_file bs=1024 count=5120000;
> date
> mer jui 26 15:36:41 CEST 2006
> 5120000+0 enregistrements lus.
> 5120000+0 enregistrements écrits.
> mer jui 26 15:38:31 CEST 2006
> 
> This seems very bad performances no ?

You can use "time dd of=/dev/zero if=big_file bs=1024 count=5120000" to get a
more precise measurement...

Bye,

Tino.