From nobody Thu Aug 05 19:25:21 2021 X-Original-To: freebsd-fs@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 681C210F867E for ; Thu, 5 Aug 2021 19:25:43 +0000 (UTC) (envelope-from joe@via.net) Received: from smtp1.via.net (smtp1.via.net [157.22.3.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "via.net", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Ggdqp2NsXz3vWd for ; Thu, 5 Aug 2021 19:25:42 +0000 (UTC) (envelope-from joe@via.net) Received: from mail.via.net (mail.via.net [157.22.3.34]) by smtp1.via.net (8.15.2/8.14.1-VIANET) with ESMTPS id 175JPYVv029470 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Thu, 5 Aug 2021 12:25:34 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.102.2 at smtp1.via.net Received: from [209.81.2.65] ([209.81.2.65]) by mail.via.net (8.15.2/8.14.1-VIANET) with ESMTP id 175JPWbM013511 for ; Thu, 5 Aug 2021 12:25:32 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.102.2 at mail.via.net From: joe mcguckin Content-Type: multipart/alternative; boundary="Apple-Mail=_2301350A-9460-4244-870B-8E682F5FBBF8" List-Id: Filesystems List-Archive: https://lists.freebsd.org/archives/freebsd-fs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-fs@freebsd.org Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.7\)) Subject: ZFS question Message-Id: Date: Thu, 5 Aug 2021 12:25:21 -0700 To: freebsd-fs X-Mailer: Apple Mail (2.3608.120.23.2.7) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (smtp1.via.net [157.22.3.5]); Thu, 05 Aug 2021 12:25:35 -0700 (PDT) X-Rspamd-Queue-Id: 4Ggdqp2NsXz3vWd X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of joe@via.net designates 157.22.3.5 as permitted sender) smtp.mailfrom=joe@via.net X-Spamd-Result: default: False [-1.30 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_SPAM_SHORT(0.60)[0.605]; FREEFALL_USER(0.00)[joe]; FROM_HAS_DN(0.00)[]; MV_CASE(0.50)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-fs@freebsd.org]; DMARC_NA(0.00)[via.net]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_HAM_LONG(-1.00)[-1.000]; RCVD_COUNT_THREE(0.00)[3]; TO_DN_ALL(0.00)[]; R_SPF_ALLOW(-0.20)[+MX]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; ASN(0.00)[asn:7091, ipnet:157.22.0.0/16, country:US]; RCVD_TLS_LAST(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_IN_DNSWL_LOW(-0.10)[157.22.3.5:from] X-ThisMailContainsUnwantedMimeParts: Y --Apple-Mail=_2301350A-9460-4244-870B-8E682F5FBBF8 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 How does ZFS keep track of drives in a dataset or VDEV? If I rearrrange = the drives in a chassis, somehow ZFS is able to make sense of the = scrambled drives and=20 mount the dataset. Clearly ZFS is tracking the drives. How does it refer to the drives = internally? By UUID, Drive Label? On some OS=E2=80=99s (Linux) there = are many options for specifying which drives make up a VDEV: UUID, = Partition Label, etc. On other OS=E2=80=99s, these schemes might not = exist (think moving drives from Linux to FreeBSD, for example). I=E2=80=99ve noticed that on Linux, drive identifiers (sda, sdb, etc) = move around after reboots. How does ZFS cope with this? Does each drive (or partition) have a header that tells ZFS that this = entity is =E2=80=98drive 2 of VDEV foo=E2=80=99? Thanks, Joe Joe McGuckin ViaNet Communications joe@via.net 650-207-0372 cell 650-213-1302 office 650-969-2124 fax --Apple-Mail=_2301350A-9460-4244-870B-8E682F5FBBF8--