From owner-freebsd-geom@FreeBSD.ORG Thu Dec 28 18:30:04 2006 Return-Path: X-Original-To: freebsd-geom@freebsd.org Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 6394316A403 for ; Thu, 28 Dec 2006 18:30:04 +0000 (UTC) (envelope-from gcubfg-freebsd-geom@m.gmane.org) Received: from ciao.gmane.org (main.gmane.org [80.91.229.2]) by mx1.freebsd.org (Postfix) with ESMTP id 15EAC13C48E for ; Thu, 28 Dec 2006 18:30:04 +0000 (UTC) (envelope-from gcubfg-freebsd-geom@m.gmane.org) Received: from root by ciao.gmane.org with local (Exim 4.43) id 1H000w-0001jN-6l for freebsd-geom@freebsd.org; Thu, 28 Dec 2006 19:30:02 +0100 Received: from 89-172-61-42.adsl.net.t-com.hr ([89.172.61.42]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 28 Dec 2006 19:30:02 +0100 Received: from ivoras by 89-172-61-42.adsl.net.t-com.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 28 Dec 2006 19:30:02 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-geom@freebsd.org From: Ivan Voras Date: Thu, 28 Dec 2006 19:27:50 +0100 Lines: 34 Message-ID: References: <20061228171858.GA11296@qlovarnika.bg.datamax> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigC0CDD9C5C2B97BF14E2645A8" X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: 89-172-61-42.adsl.net.t-com.hr User-Agent: Thunderbird 1.5.0.9 (Windows/20061207) In-Reply-To: X-Enigmail-Version: 0.94.1.2 Sender: news Subject: Re: gstripe performance scaling with many disks X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Dec 2006 18:30:04 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigC0CDD9C5C2B97BF14E2645A8 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Ivan Voras wrote: > I'll take a shot at this: Since maximum kernel reads are still limited > to 128 KB/s, by adding more drives you're making individual requests > shorter. I.e. with one drive, it gets 128 KB requests, with two, each > gets 64 KB, with 16, each gets 8 KB. So network & kernel latency become= s > visible. Btw. if I'm right, you should be able to observe this with gstat and/or iostat. If you don't see it, then it's possible I'm wrong :) --------------enigC0CDD9C5C2B97BF14E2645A8 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.4 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFFlAymldnAQVacBcgRAht9AKCo4K2oMISgKKOTQeUeQpNToEhhRwCglpAc hQpiTQrnYBwjCOXyG8l/oyA= =UuL+ -----END PGP SIGNATURE----- --------------enigC0CDD9C5C2B97BF14E2645A8--