From: "Eric M. Hopper" <hopper@omnifarious.mn.org>
To: linux-lvm@sistina.com
Subject: Re: [linux-lvm] Apparent performance degradation for each PV with striping
Date: Sun, 18 Mar 2001 23:20:12 -0600 [thread overview]
Message-ID: <20010318232012.A1169@omnifarious.mn.org> (raw)
In-Reply-To: <3AB59501.FF6ED9F3@dataventures.com>; from dlt@dataventures.com on Sun, Mar 18, 2001 at 10:11:29PM -0700
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On Sun, Mar 18, 2001 at 10:11:29PM -0700, Donald Thompson wrote:
> I started playing with iostat tonight and saw a few things I didn't
> really expect to see.
>
> I've got a volume group consisting of 4 82 gig drives. All 4 are IDE
> drives. Reading directly from the raw device, a PV in this case, with
> something like
>
> dd if=/dev/ide/host0/bus0/target0/lun0/disc of=/dev/null
Have you played with hdparm to try to tune the way the kernel
talks to your IDE drives?
That may be the reason for being CPU bound. The kernel tends to
default to the slowest possible method because there are a lot of bad
IDE controllers and drives out there that will trash your data if you
try to talk to them in a way they aren't expecting.
Have fun (if at all possible),
--
The best we can hope for concerning the people at large is that they
be properly armed. -- Alexander Hamilton
-- Eric Hopper (hopper@omnifarious.mn.org http://www.omnifarious.org/~hopper) --
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next prev parent reply other threads:[~2001-03-19 5:20 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-03-19 5:11 [linux-lvm] Apparent performance degradation for each PV with striping Donald Thompson
2001-03-19 5:20 ` Eric M. Hopper [this message]
2001-03-22 8:55 ` Russell Coker
2001-03-19 6:03 ` lvm
2001-03-19 7:05 ` Donald Thompson
2001-03-19 9:15 ` Joe Thornber
2001-03-19 7:06 ` Jason Walker
2001-03-19 8:48 ` Oleg Volkov
-- strict thread matches above, loose matches on Subject: below --
2001-03-19 13:34 S. Michael Denton
2001-03-19 13:44 ` Steven Lembark
2001-03-22 8:54 ` Russell Coker
2001-03-22 9:53 ` Ragnar Kjørstad
2001-03-22 12:19 ` zoo1
2001-03-22 8:58 ` Russell Coker
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