Subject: Re: vfs.lfs.pagetrip--unexpected result
To: Blair Sadewitz <>
From: Thor Lancelot Simon <>
List: current-users
Date: 12/11/2006 10:49:49
On Mon, Dec 11, 2006 at 04:15:10AM -0500, Blair Sadewitz wrote:
> Yes, I understand this, and what vfs.lfs.pagetrip is (I can run sysctl
> -d ;).  The thing is, even higher values than that--even by a few
> thousand pages, dramatically decrease throughput.  I figured it would
> be as simple as your account sounds, but it isn't.
> I have found the best overall performance in real-world tasks comes
> with using the aggregate bandwidth of all disks in my ccd
> (vfs.lfs.pagetrip=8596), using an LFS segment size figured from the
> same (17199 blocks), and a stripe size of 5733 blocks (1/3 segment
> size).

How are you measuring latency?