From owner-freebsd-questions@FreeBSD.ORG Sun Jan 17 21:43:11 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 616791065679 for ; Sun, 17 Jan 2010 21:43:11 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from smtp.infracaninophile.co.uk (gate6.infracaninophile.co.uk [IPv6:2001:8b0:151:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id 10BE18FC1B for ; Sun, 17 Jan 2010 21:43:09 +0000 (UTC) Received: from happy-idiot-talk.infracaninophile.co.uk (localhost [IPv6:::1]) (authenticated bits=0) by smtp.infracaninophile.co.uk (8.14.4/8.14.3) with ESMTP id o0HLgsSM076117; Sun, 17 Jan 2010 21:43:00 GMT (envelope-from m.seaman@infracaninophile.co.uk) X-DKIM: Sendmail DKIM Filter v2.8.3 smtp.infracaninophile.co.uk o0HLgsSM076117 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=infracaninophile.co.uk; s=201001-infracaninophile; t=1263764580; bh=LVBjivjwrOItplhPNq9u5PYq6PTM691WKk0L74wvGWs=; h=Message-ID:Date:From:MIME-Version:To:CC:Subject:References: In-Reply-To:Content-Type:Cc:Content-Type:Date:From:In-Reply-To: Message-ID:Mime-Version:References:To; z=Message-ID:=20<4B538459.7090601@infracaninophile.co.uk>|Date:=20S un,=2017=20Jan=202010=2021:42:49=20+0000|From:=20Matthew=20Seaman= 20|Organization:=20Infracaninophi le|User-Agent:=20Thunderbird=202.0.0.23=20(X11/20100114)|MIME-Vers ion:=201.0|To:=20Mike=20Clarke=20|CC: =20freebsd-questions@freebsd.org,=20Pieter=20de=20Goeje=20|Subject:=20Re:=20Newbie=20gmirror=20questions|Referenc es:=20<201001152334.52978.jmc-freebsd2@milibyte.co.uk>=20<20100117 1639.41777.jmc-freebsd2@milibyte.co.uk>=20<4B534661.7030905@infrac aninophile.co.uk>=20<201001172122.15128.jmc-freebsd2@milibyte.co.u k>|In-Reply-To:=20<201001172122.15128.jmc-freebsd2@milibyte.co.uk> |X-Enigmail-Version:=200.95.6|Content-Type:=20multipart/signed=3B= 20micalg=3Dpgp-sha256=3B=0D=0A=20protocol=3D"application/pgp-signa ture"=3B=0D=0A=20boundary=3D"------------enigDC673569D521166F44C4F 3D6"; b=ubLA81JDFSWOpAlimJQEvqW5ehKxq6CaeVhzgYDzFklAmLfkuUgv9cunxruKrf15r m7Q1EQVtjbNm1Ddntx2SNaO6c7fVlT0LTijYPWbNPIW3K2ctTQzGTouFhV8nHsJ98Y WY6M2yO7E15I/PmK0wkE3Xi+N2cf6mwmXsC1cW+Y= X-Authentication-Warning: happy-idiot-talk.infracaninophile.co.uk: Host localhost [IPv6:::1] claimed to be happy-idiot-talk.infracaninophile.co.uk Message-ID: <4B538459.7090601@infracaninophile.co.uk> Date: Sun, 17 Jan 2010 21:42:49 +0000 From: Matthew Seaman Organization: Infracaninophile User-Agent: Thunderbird 2.0.0.23 (X11/20100114) MIME-Version: 1.0 To: Mike Clarke References: <201001152334.52978.jmc-freebsd2@milibyte.co.uk> <201001171639.41777.jmc-freebsd2@milibyte.co.uk> <4B534661.7030905@infracaninophile.co.uk> <201001172122.15128.jmc-freebsd2@milibyte.co.uk> In-Reply-To: <201001172122.15128.jmc-freebsd2@milibyte.co.uk> X-Enigmail-Version: 0.95.6 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enigDC673569D521166F44C4F3D6" X-Virus-Scanned: clamav-milter 0.95.3 at happy-idiot-talk.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, score=-3.0 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VERIFIED,NO_RELAYS autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on happy-idiot-talk.infracaninophile.co.uk Cc: Pieter de Goeje , freebsd-questions@freebsd.org Subject: Re: Newbie gmirror questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 17 Jan 2010 21:43:11 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigDC673569D521166F44C4F3D6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Mike Clarke wrote: > On Sunday 17 January 2010, Matthew Seaman wrote: >=20 >> Mike Clarke wrote: >>> Actually I was more concerned about what happens when I boot into >>> another OS like Windows or Linux on one of the spare slices - I'm >>> assuming that I have to apply gmirror to the whole disk rather than >>> just selected slices? >> You can't do this. gmirror is FreeBSD specific, and other OSes can't >> deal with it. You can take your two drives, partition them (fdisk) >> and then create a gmirror across the slices you assign to FreeBSD. >=20 > This will make things a lot easier for me. I think all the examples of = > gmirror I've seen used things like /dev/da0 as the provider in label=20 > commands so I assumed that I had to use the whole physical disk but if = > I can mirror individual slices then I have much more flexibility. >=20 > My motherboard has a UDMA133 controller for ata0 & ata1 (which I don't = > use) and 2 SATA controllers for ata2 to ata5 so with my 2 SATA drives=20 > spread between the controllers on channels 2 & 4 I could have something= =20 > like /dev/mirror/gm1 provided by /dev/ad2s1 & /dev/ad4s1=20 > and /dev/mirror/gm2 provided by /dev/ad2s2 & /dev/ad4s2 for a couple of= =20 > FreeBSD systems. That will leave me with 2 spare slices on each drive=20 > for other purposes. Any Windows or Linux stuff I put on tends to be=20 > mainly experimental and less long term than my FreeBSD system so don't = > really need the resilience of being mirrored. >=20 Yes -- there's an On-Lamp article by Dru Lavigne that has been particular= ly influential, and gmirror'ing whole disks is the best way forwards for the= vast majority of cases where you've a server dedicated to one OS. However, one of the really amazingly brilliant things about geom is that just about any disk / storage related thing can be a geom provider, and=20 geom constructs will nest very happily. Here's a howto for setting up gmirror across a pair of slices: http://people.freebsd.org/~rse/mirror/ It's fairly old now, but the essentials are still correct. The one thing= that has changed in the intervening time is what is the best algorithm to use for the gmirror. Up until the release of 8.0, 'round-robin' was=20 virtually always the right choice, but nowadays 'load' is preferred. All that means, is change the following line in rse's article from: gmirror label -v -n -b round-robin ${gm} /dev/${d2}s1 to gmirror label -v -n -b load ${gm} /dev/${d2}s1 Cheers, Matthew --=20 Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard Flat 3 PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate Kent, CT11 9PW --------------enigDC673569D521166F44C4F3D6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEAREIAAYFAktThF4ACgkQ8Mjk52CukIwwfACeOmZuTNFrWqyYKSD7f2r5xKZ6 j6IAoITJjkmu5GxJoL9xBL/ZmQ7T149H =VqSw -----END PGP SIGNATURE----- --------------enigDC673569D521166F44C4F3D6--