From owner-freebsd-stable@FreeBSD.ORG Tue May 24 19:05:23 2011 Return-Path: Delivered-To: stable@freebsd.org Received: from mx2.freebsd.org (mx2.freebsd.org [IPv6:2001:4f8:fff6::35]) by hub.freebsd.org (Postfix) with ESMTP id 976C1106564A for ; Tue, 24 May 2011 19:05:23 +0000 (UTC) (envelope-from ae@FreeBSD.org) Received: from [127.0.0.1] (hub.freebsd.org [IPv6:2001:4f8:fff6::36]) by mx2.freebsd.org (Postfix) with ESMTP id B7DA714DA85; Tue, 24 May 2011 19:04:37 +0000 (UTC) Message-ID: <4DDC013E.5040107@FreeBSD.org> Date: Tue, 24 May 2011 23:04:30 +0400 From: "Andrey V. Elsukov" User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.17) Gecko/20110429 Thunderbird/3.1.10 MIME-Version: 1.0 To: Victor Balada Diaz References: <20110524132028.GE1291@equilibrium.bsdes.net> <4DDBC4A9.7040404@FreeBSD.org> <20110524150951.GF1291@equilibrium.bsdes.net> <4DDBD73B.7090600@FreeBSD.org> <20110524172718.GG1291@equilibrium.bsdes.net> In-Reply-To: <20110524172718.GG1291@equilibrium.bsdes.net> X-Enigmail-Version: 1.1.2 OpenPGP: id=10C8A17A Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigDF77CE52950761F9D34044A6" Cc: stable@freebsd.org Subject: Re: gpart usage X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 May 2011 19:05:23 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigDF77CE52950761F9D34044A6 Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: quoted-printable On 24.05.2011 21:27, Victor Balada Diaz wrote: >>> So the 16 sector offset in BSD label is really needed or isn't? >> >> First 8 KBytes of the freebsd partition are reserved for the boot code= >> (/boot/boot). The table of BSD partitions itself is located in the >> second sector. So, if you plan to create freebsd-ufs partition you can= >> create it without any offset. But if it will be not an UFS partition, >> then i would created it with offset, otherwise you can wipe the BSD la= bel. >=20 > Who's the one reserving the 16 sector (8 KBytes) offset? the UFS filesy= stem? the BSD slice/disklabel > provider? the MBR provider? BSD slice provider. > If i understood it correctly, it would be like: >=20 > Sector 0: usual IBM-PC MBR, MBR provider doesn't need anything more > Sector 1-62: Reserved by MBR scheme (dunno why, but seems to be the cas= e, probably CHS alignment) start: 63 Yes, currently we are actively discussing about this in the freebsd-geom@ maillist. > Sector 63: BSD scheme unused because on disk metadata is stored on seco= nd sector Here is saved the boot1 stage of /boot/boot. > Sector 64: BSD scheme (disklabel) on disk data (148 + 8 * 16 =3D 276 by= tes according to sys/disklabel.h) GEOM_PART_BSD supports up to 20 partitions. > Sectors 65-(63+16): Reserved by ??? for /boot/boot Here is saved the boot2 stage of /boot/boot. > Sectors (63+16)+: partitions If you will not use offset for the first BSD partition, then you can wipe BSD scheme with this command: # dd if=3D/dev/zero of=3D/dev/da0s1a count=3D2 --=20 WBR, Andrey V. Elsukov --------------enigDF77CE52950761F9D34044A6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (FreeBSD) iQEcBAEBAgAGBQJN3AFDAAoJEAHF6gQQyKF6DoYH/i6bPG1tkPpWdvZMaNWe5n8l HKP0LlKRwQ/t8x9txvwkCKjzwrRlPKyLF0+VvLxXRTIZfbEmZ0jjsOfUEr4VdUx7 t+2KI/k7Jd6/3jeab7JlHERhUkqZhfdn6BzsUQy9DP4f7+vaey747NpRxh5CYC1p 4FOP6MhjyDmnwKNLr9T1cVHmyPn3NKHwomHv6NPoAtJp/ECGURewcob1ovaoYAam 6Ag4Udndlh+93qfxn0Wxwlxf5wDyegTcP5U+K4lvV6NnYPltn2/syWGIK66n9VCf 3bYbwTJ57PQ/uW1NwgbdypH2QLyK6hsuUFSXKQNNrMxTbGacZ4Nhq3n1QjrNFps= =vbI/ -----END PGP SIGNATURE----- --------------enigDF77CE52950761F9D34044A6--