From owner-freebsd-hackers@freebsd.org Sun Jul 29 20:49:45 2018 Return-Path: Delivered-To: freebsd-hackers@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 C25551062DB4 for ; Sun, 29 Jul 2018 20:49:45 +0000 (UTC) (envelope-from dcrosstech@gmail.com) Received: from mail-oi0-x233.google.com (mail-oi0-x233.google.com [IPv6:2607:f8b0:4003:c06::233]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 3F24679147 for ; Sun, 29 Jul 2018 20:49:45 +0000 (UTC) (envelope-from dcrosstech@gmail.com) Received: by mail-oi0-x233.google.com with SMTP id k81-v6so17718680oib.4 for ; Sun, 29 Jul 2018 13:49:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=c/lykBerzaN0BXPnMAJvKwIHAfY5AfiDmiL/1k6bFi4=; b=pyjH5rqbpwv0o2b0VKfEW1nn5nsSxEckx6molV6euMoAB6ljXWTydWi2GdAPJ67Ue9 CtMTrDmsI3YV+yL1boQAnIthNyjMyF5LXh2hFjiRhYuchcGdvaE9mgBWMCA0B39buWfE z1Sx3ofW1rLsB1e9M9G6VjwFPt2+4waIiPkepHnjtMZZU3ZL3EnhsxmALWpHa2E+1zzu jRziSyPjLfjrHI7yVnJCUnst0OuvQN5N8hMkoxErhhanumFykWsCbj1e2tEdU9g3prWv 0xh1T1AuviqQRS5xWYgKtKNbMYqHWh3xwtEeY8wAjB2uH9qcVbeM/JBo78Vl38jcLxbf Uigg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=c/lykBerzaN0BXPnMAJvKwIHAfY5AfiDmiL/1k6bFi4=; b=miU/8oMw9snpNz2AzQdYLZzbC6oZJ0C+dz7LU2qkeXVFJjOgeGeac7CMlDT14UA/hy e62RWb7uanJKxTl/H1Q5szxoKpB2sUL2Ud7Lcvla5GOKTWhHehAUs9XLgLBgeT0Hj6J/ d6ksaHes5ai9V10CAwzT+qLoLmgvTD7Qpz7i/KniWz4Lsz6BPZ54GvNSeDM1M77Q5ABd 4EQqPePCV/s+zXZKol5yGzi8z17QmRDfCHGlumSqRvqLJxEpBl80FcH5C/dhH5YGuFn2 c90Ekr93DmBFFil8Ho5JwlLIEAIsF2Wmk60Cgqlk8Ajw5+FulVl+NpGq/haJ582FvGyA 735A== X-Gm-Message-State: AOUpUlEkKbX7NJY14o3Di00JvzTgnr90bkajUN/zMqOXdoRpjevU3E3W hyFkfIF0pptb7CjY7uwz1pCtgbzoL5s9gtGW2irerg== X-Google-Smtp-Source: AAOMgpfWQShIRX0t4uCAFZdBdjPyM340EMilzKJo8q7sqMiEJCZ89Engphe00GRrixlqQ75DDNB6s+oPvjOsYFyM/D8= X-Received: by 2002:aca:6908:: with SMTP id e8-v6mr2280310oic.302.1532897384345; Sun, 29 Jul 2018 13:49:44 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a9d:7017:0:0:0:0:0 with HTTP; Sun, 29 Jul 2018 13:49:44 -0700 (PDT) From: David Cross Date: Sun, 29 Jul 2018 16:49:44 -0400 Message-ID: Subject: Request for comments, new geom part type alias: freebsd-geom To: FreeBSD Hackers Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.27 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 29 Jul 2018 20:49:46 -0000 I'd like to propose that we create a GPT partition for geom labeled partitions (gmirror, gstripe, geli, etc.. anything that can be 'tasted' and automatically determined.) called 'freebsd-geom'. There are numerous cases where you shouldn't have a raw geom on a disk (for example, imagine a raid 10 of a filesystem with VMs on it..on a raw disk its possible that the lead block happens to line up with a VM disk image or anything else a BIOS may determine is bootable). So the question becomes which part id to use; IF its a mirror of a swap of UFS it seems perfectly reasonable to use freebsd-swap or freebsd-ufs (if a bit dangerous). If its a mirror or a geli then you can again be in the situation where the boot blocks (or something else), in certain circumstances mistakes these for raw filesystems with similarly calamitous results. Given these, it seems a 'freebsd-geom' (or similar) seems entirely appropriate; we can mark these for what they really are, and eliminate these cases where the system misinterprets intentions based on ambiguous data.