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From: Mario Giammarco <mgiammarco@virgilio.it>
To: Craig Tierney <ctierney@hpti.com>, linux-scsi@vger.kernel.org
Subject: Re: Best driver for qlogic 2200 fc?
Date: Tue, 18 Nov 2003 20:19:52 +0100	[thread overview]
Message-ID: <1069183192.4927.3.camel@cala> (raw)
In-Reply-To: <1069085218.14602.63.camel@localhost.localdomain>

Il lun, 2003-11-17 alle 17:06, Craig Tierney ha scritto:

> > Unfortunately it gives me slow performance (sequential read of 30mb/sec on a 
> > seagate 318452fc that can do 60mb/sec sequential read).
> > 
> 
> What is your write performance?  Have you tried
> to tune /proc/sys/vm/{min,max}-readahead?

I have tuned readahead and not it goes 50 mb.
I am shocked, why I need to tune it?
Usually I do an hdparm -t -T to see if hard disk is good
(and eventually hdparm again to tune ide interface)
Without tuning I can reach sequential read of more than 60 mb using raid0.
I do not understand why the OS cannot use the full speed of this FC drive.

OTOH side I discovered that (in a raid1 array ) the two seagate write speed is very low: 10mb/s, why?


      parent reply	other threads:[~2003-11-18 19:20 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-11-17 16:11 Best driver for qlogic 2200 fc? Mario Giammarco
     [not found] ` <1069085218.14602.63.camel@localhost.localdomain>
2003-11-18 19:19   ` Mario Giammarco [this message]

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