From nobody Sun Jul 17 16:28:57 2022 X-Original-To: questions@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4Lm9XQ224xz4WjL7 for ; Sun, 17 Jul 2022 16:29:10 +0000 (UTC) (envelope-from taceant@gmail.com) Received: from mail-vs1-xe32.google.com (mail-vs1-xe32.google.com [IPv6:2607:f8b0:4864:20::e32]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Lm9XP3jtPz3r4Z for ; Sun, 17 Jul 2022 16:29:09 +0000 (UTC) (envelope-from taceant@gmail.com) Received: by mail-vs1-xe32.google.com with SMTP id j1so8508376vsr.4 for ; Sun, 17 Jul 2022 09:29:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:from:date:message-id:subject:to; bh=902mwxuZlmz1fmw2qlseQsk3fHFG6T8Y0LBdqiuMMIU=; b=QgFfqucA0aHWD5hioBfoqFYmS+TWXzkfdGT9sdsLCxrkrwNSRxdecU4uNc9VUZrnX3 3lDo33WqyipRgExl/MtfVELJTOJJMXEJOftpWP5BlQC9XWZmBrgPlwGBPh/t2Ez0cQjy Wq2OdsdFC4N6UnEVq9rfbTg5njgI34lsFh6krAXMF3q/gq5zeqC5aKIXmsdVN16cU4bI Kn441q8x4IcYrN1LO6v/xsyrtEsTbg9GTdroYyjEcEMwsMQ9THIfOk066n6XiOQPJGH7 Pvo9KKQ1v5ZLbRSfwODqyXlXr8eW12RERlr7fyISVwDy51h9qQfcz/qllrxDnDecZ8e6 7gwA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=902mwxuZlmz1fmw2qlseQsk3fHFG6T8Y0LBdqiuMMIU=; b=1iNpEO5qaNUHcI2n6LM0nFfGq0Rf/He8ajvcrYRKf+AkdBozbgvXN70yJTDxHZ0RrC 6gUNGvemF4eqJvVK+B1GjmQgVko8Np+VIkWBRhZmJX1Bvy0arowkyOyoPZqLqV8K7QHp 0crReDbdeeXjQfxunraMRRz68XO5fYQT5bLvHzgXCkFJ1qQQVh5pwoGu2YAIr+/BPQpX du0Qcz11GOzcU6miRKNmpHR4tXGPYpQqIEV3Ced/3kEtIHnsl11xhrH5UGzQi1H34S+C QzSMY9hW/jJZbM9t7bh+1nfbVHKwgeyqKCWNr5LCWZwaQfnlMzwq4FRNS+FYjsawqubw MKow== X-Gm-Message-State: AJIora97jMKjyHK2fjHUGMofi/YERjGNCZT8+qbpzKiDogBdeJlVFsCv z23VwxUVPEhnCbTCNb5RckWKoU0WXC6rqSGcus5e74Go0ms= X-Google-Smtp-Source: AGRyM1t9mJG9XU0/3CQb8qhfKScRkHbsGHoPMO8YjtMDn42IvYWxNrupkXooUJ05l9/pfK0MWxHSNDndWeNTnXsjLM4= X-Received: by 2002:a67:ca0c:0:b0:351:3449:bcef with SMTP id z12-20020a67ca0c000000b003513449bcefmr7827551vsk.48.1658075348896; Sun, 17 Jul 2022 09:29:08 -0700 (PDT) List-Id: User questions List-Archive: https://lists.freebsd.org/archives/freebsd-questions List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org MIME-Version: 1.0 From: Taceant Omnes Date: Sun, 17 Jul 2022 17:28:57 +0100 Message-ID: Subject: rationale for default ZFS datasets To: FreeBSD Questions List Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 4Lm9XP3jtPz3r4Z X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20210112 header.b=QgFfqucA; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of taceant@gmail.com designates 2607:f8b0:4864:20::e32 as permitted sender) smtp.mailfrom=taceant@gmail.com X-Spamd-Result: default: False [-3.94 / 15.00]; NEURAL_HAM_LONG(-1.00)[-0.998]; NEURAL_HAM_SHORT(-1.00)[-0.995]; NEURAL_HAM_MEDIUM(-0.95)[-0.949]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36:c]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20210112]; MIME_GOOD(-0.10)[text/plain]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MLMMJ_DEST(0.00)[questions@freebsd.org]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[gmail.com]; RCVD_IN_DNSWL_NONE(0.00)[2607:f8b0:4864:20::e32:from]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; ARC_NA(0.00)[]; DKIM_TRACE(0.00)[gmail.com:+]; RCVD_COUNT_TWO(0.00)[2]; FREEMAIL_FROM(0.00)[gmail.com]; FROM_HAS_DN(0.00)[]; MID_RHS_MATCH_FROMTLD(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[questions@freebsd.org]; RCVD_TLS_LAST(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; TO_DN_ALL(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim] X-ThisMailContainsUnwantedMimeParts: N If at installation time one chooses automatic guided ZFS install, the result is a set of datasets as below. Presumably this default set is meant to cater for the most common use cases. What is not clear to me is the rationale for that particular shape. It may be explained somewhere on the internet. If anybody knows where please send me the link. Otherwise I will ask a few questions. /var and /usr both merit a dataset of their own, and under them there are a few other nested datasets. What is not clear to me is why only these particular folders merit their own datasets, likewise with /tmp. Perhaps it is so that one has the ability to do snapshots? zroot could be left unmounted, so why is it mounted at /zroot? why zroot/ROOT needs a dataset of its own, and why is it unmounted? what is the purpose of zroot/ROOT/default? Lots of questions! As I said, if this is explained somewhere please let me know where. root@fbsd-vm:~ # zfs list NAME USED AVAIL REFER MOUNTPOINT zroot 4.38G 32.0G 96K /zroot zroot/ROOT 3.40G 32.0G 96K none zroot/ROOT/default 3.40G 32.0G 3.40G / zroot/tmp 1001M 32.0G 1001M /tmp zroot/usr 508K 32.0G 96K /usr zroot/usr/home 220K 32.0G 148K /usr/home zroot/usr/ports 96K 32.0G 96K /usr/ports zroot/usr/src 96K 32.0G 96K /usr/src zroot/var 1.02M 32.0G 96K /var zroot/var/audit 96K 32.0G 96K /var/audit zroot/var/crash 96K 32.0G 96K /var/crash zroot/var/log 540K 32.0G 540K /var/log zroot/var/mail 124K 32.0G 124K /var/mail zroot/var/tmp 96K 32.0G 96K /var/tmp