From owner-freebsd-questions@freebsd.org Sat Jul 7 22:54:38 2018 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B8C421035169 for ; Sat, 7 Jul 2018 22:54:38 +0000 (UTC) (envelope-from jude.obscure@yandex.com) Received: from forward106j.mail.yandex.net (forward106j.mail.yandex.net [IPv6:2a02:6b8:0:801:2::109]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "forwards.mail.yandex.net", Issuer "Yandex CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 3F79A70826 for ; Sat, 7 Jul 2018 22:54:38 +0000 (UTC) (envelope-from jude.obscure@yandex.com) Received: from mxback6g.mail.yandex.net (mxback6g.mail.yandex.net [IPv6:2a02:6b8:0:1472:2741:0:8b7:167]) by forward106j.mail.yandex.net (Yandex) with ESMTP id C6D8C180271C for ; Sun, 8 Jul 2018 01:54:35 +0300 (MSK) Received: from smtp1p.mail.yandex.net (smtp1p.mail.yandex.net [2a02:6b8:0:1472:2741:0:8b6:6]) by mxback6g.mail.yandex.net (nwsmtp/Yandex) with ESMTP id bq7YLa7yAG-sZ9uOXY1; Sun, 08 Jul 2018 01:54:35 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.com; s=mail; t=1531004075; bh=jzMrIEnyGJLSBNWa0zWM6nrSosgcVsfR1Kb1QmHUZQE=; h=Subject:To:References:From:Message-ID:Date:In-Reply-To; b=QPIfg0Ju9+uxt+2DUUJAha/4AgZx12jHiS5zkiTaKhKmdyhSgnj3Id/IQFBU4eGxR ecd5jmmPZfm5kbUd8xB3CJoA39u55UXT4lW50JlRbMewOlOP3+s8UUkpnRFXvE+5U3 3zHLL9h2EJV5l6zKcLPBQWvHCn1oSPgmJDLeR73U= Received: by smtp1p.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id 4rsb09Sq7D-rsl49r4H; Sun, 08 Jul 2018 01:53:54 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.com; s=mail; t=1531004035; bh=jzMrIEnyGJLSBNWa0zWM6nrSosgcVsfR1Kb1QmHUZQE=; h=Subject:To:References:From:Message-ID:Date:In-Reply-To; b=IeEqhx/JksT+vxOW16oN+YEP7mxTfetpnbKdeW3BoG2ugGXX3jCxNQhs6r9LfZwpB Zd8FukLApFtHI5RghiKnXtkLIq3HqYisu/mvsUAU7iTK4aUQFzSqNY4G2JcTEvV5UE ZR5F5HGyUhN2yt6xxr8C5KEKXIqFiSwR7hHOA88M= Authentication-Results: smtp1p.mail.yandex.net; dkim=pass header.i=@yandex.com Subject: Re: Fwd: A request for unnested UFS implementation in MBR To: FreeBSD Questions References: <98201d37-2d65-34c6-969e-c9649f1a3ab1@yandex.com> <20180707231908.65a2e973.freebsd@edvax.de> <20180708001336.4097d20e.freebsd@edvax.de> <6bbfdaad-6872-1a6b-f176-471e57ac8d0a@yandex.com> <20180708004645.5a39c930.freebsd@edvax.de> From: Manish Jain Message-ID: <2449a381-01db-a0b7-a306-cbadf35fb504@yandex.com> Date: Sun, 8 Jul 2018 04:21:52 +0530 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180708004645.5a39c930.freebsd@edvax.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 07 Jul 2018 22:54:39 -0000 On 07/08/18 04:16, Polytropon wrote: > On Sun, 8 Jul 2018 03:50:09 +0530, Manish Jain wrote: >> MBR permits 3 primary partitions + 1 EBR slice. >> >> What I meant was one of the three partitions serving as FreeBSD / (UFS, >> unnested), and any extra filesystems the user needs reside within the EBR. >> >> In other words, an option for UFS to be just like Ext2 in this respect. > > Yes, that is possible if you simply format that slice. It > does not matter if it's a DOS primary partition or a logical > volume inside a DOS extended partition. What you basically > do is that you get a 'c'-labeled BSD partition (where 'c' > means "the whole thing", in this case, a partition. > > Let's say you have the following construct: > > da0 = { [da0s1] [da0s2] [da0s3] [da0s5 da0s6] } > > We assume da0s1 - da0s3 are used for DOS, "Windows", maybe > one Linux Ext2 data partition - 3 DOS primary partitions. > And then we assume one DOS extended partition with two > logical volumes in it. You can now use newfs to format > them: > > # newfs /dev/da0s5 > # newfs /dev/da0s6 > > This gives you /dev/da0s5c and /dev/da0s6c (where the 'c' > can be omitted, and you can use /dev/da0s5 and /dev/da0s6 > instead), and you could for example do: > > # mount -t ufs /dev/da0s5 /usr > # mount -t ufs /dev/da0s6 /var > > Entries in /etc/fstab will attach them at boot time. > > However, there is a problem with booting, as I already said. > FreeBSD requires an 'a'-labeled BSD partition to boot from, > MBR or not (or its equivalent in GPT, freebsd-boot, to > construct a "boot chain" from the freebsd-boot to a > freebsd-ufs partition which holds /), and this partition > will then be the / partition. > > As you can see, this is not possible. You cannot have a > 'a' partition when you can only create a 'c' partition > on a bare slice (coverin the whole slice). > > > > Resources: > > https://www.freebsd.org/doc/handbook/disk-organization.html > > http://www.wonkity.com/~wblock/docs/html/disksetup.html > > https://wiki.pacbsd.org/index.php/Partitioning Then how do the 'a' and 'c' partitions get accommodated in GPT ? Poly, your thinking is wrong. The BSD schema served its purpose. Now, we should think about retiring it. Or at least, provide it as only an option to conform with past behaviour. But definitely not as a matter of forced usage. Tx MJ