From nobody Sat Apr 22 15:46:13 2023 X-Original-To: freebsd-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 4Q3bNG36wfz46v1r for ; Sat, 22 Apr 2023 15:46:22 +0000 (UTC) (envelope-from paul@gromit.dlib.vt.edu) Received: from gromit.dlib.vt.edu (gromit.dlib.ipv6.vt.edu [IPv6:2001:468:c80:a103:2:5000:5555:5555]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4Q3bNG1Pmwz3JKt for ; Sat, 22 Apr 2023 15:46:22 +0000 (UTC) (envelope-from paul@gromit.dlib.vt.edu) Authentication-Results: mx1.freebsd.org; none Received: from 2012-mbp.gromit23.net (unknown [73.99.214.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by gromit.dlib.vt.edu (Postfix) with ESMTPSA id 2F65A3E8A4; Sat, 22 Apr 2023 11:46:14 -0400 (EDT) Content-Type: text/plain; charset=us-ascii 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 (Mac OS X Mail 13.4 \(3608.120.23.2.7\)) Subject: Re: ZFS on root with dedupe From: Paul Mather In-Reply-To: Date: Sat, 22 Apr 2023 11:46:13 -0400 Cc: FreeBSD Content-Transfer-Encoding: quoted-printable Message-Id: <361F0E2D-C885-4491-9D66-CC077CEE1BB4@gromit.dlib.vt.edu> References: To: Robert Fitzpatrick X-Mailer: Apple Mail (2.3608.120.23.2.7) X-Rspamd-Queue-Id: 4Q3bNG1Pmwz3JKt X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:1312, ipnet:2001:468:c80::/48, country:US] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-ThisMailContainsUnwantedMimeParts: N On Apr 22, 2023, at 11:25 AM, Robert Fitzpatrick = wrote: > Hi, >=20 > I installed FreeBSD 13.1 server with ZFS raid 10 to serve a PostgreSQL = database, LDAP and DNS. I never noticed until today, I installed some = more memory and was checking status after the starting up. DEDUP appears = enabled, is that by default? I certainly did not enable. Does this mean = it is in fact enabled and what are the repercussions of disabling now? >=20 >> root@db1:~ # zpool list >> NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP = HEALTH ALTROOT >> zdb1 262G 26.1G 236G - - 7% 9% 1.00x = ONLINE - >> root@db1:~ # zpool status >> pool: zdb1 >> state: ONLINE >> scan: scrub repaired 0B in 00:04:52 with 0 errors on Thu Apr 13 = 10:46:22 2023 >> config: >> NAME STATE READ WRITE CKSUM >> zdb1 ONLINE 0 0 0 >> mirror-0 ONLINE 0 0 0 >> ada0p3 ONLINE 0 0 0 >> ada1p3 ONLINE 0 0 0 >> mirror-1 ONLINE 0 0 0 >> ada2p3 ONLINE 0 0 0 >> ada3p3 ONLINE 0 0 0 >> root@db1:~ # zfs list >> NAME USED AVAIL REFER MOUNTPOINT >> zdb1 26.0G 228G 96K /zdb1 >> zdb1/ROOT 24.8G 228G 96K none >> zdb1/ROOT/default 24.8G 228G 14.6G / >> zdb1/tmp 1.12M 228G 200K /tmp >> zdb1/usr 1.17G 228G 96K /usr >> zdb1/usr/home 1.31M 228G 1.30M /usr/home >> zdb1/usr/ports 1.17G 228G 1.17G /usr/ports >> zdb1/usr/src 96K 228G 96K /usr/src >> zdb1/var 5.35M 228G 96K /var >> zdb1/var/audit 96K 228G 96K /var/audit >> zdb1/var/crash 96K 228G 96K /var/crash >> zdb1/var/log 4.78M 228G 660K /var/log >> zdb1/var/mail 200K 228G 144K /var/mail >> zdb1/var/tmp Just because there is a DEDUP column in the "zpool list" output does not = mean deduplication is enabled. Deduplication is a per-fileset option, = so a better way of determining whether it is enabled for any of your ZFS = filesets is to execute the following command: zfs get dedup That will show you the "dedup" property for all of your filesets. In my = case, all the non-snapshot filesets show "dedup" as being "off" even = though I get "DEDUP" shown as "1.00x" in the "zpool list" output. = (Which still makes sense: 1.00x deduplication is consistent with = deduplication being off.) Cheers, Paul.=