From owner-freebsd-fs@freebsd.org Sat Aug 15 10:47:54 2020 Return-Path: Delivered-To: freebsd-fs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id DCFD13B5313 for ; Sat, 15 Aug 2020 10:47:54 +0000 (UTC) (envelope-from Alexander@leidinger.net) Received: from mailgate.Leidinger.net (bastille.leidinger.net [89.238.82.207]) (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 4BTH894V1qz3dpw for ; Sat, 15 Aug 2020 10:47:53 +0000 (UTC) (envelope-from Alexander@leidinger.net) Received: from outgoing.leidinger.net (p508d5858.dip0.t-ipconnect.de [80.141.88.88]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-256)) (Client did not present a certificate) by mailgate.Leidinger.net (Postfix) with ESMTPSA id E0C42D42A for ; Sat, 15 Aug 2020 12:47:41 +0200 (CEST) Received: from webmail.leidinger.net (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-256) server-digest SHA256) (Client did not present a certificate) by outgoing.leidinger.net (Postfix) with ESMTPS id 56BDE14E1 for ; Sat, 15 Aug 2020 12:47:23 +0200 (CEST) Date: Sat, 15 Aug 2020 12:47:23 +0200 Message-ID: <20200815124723.Horde.XErLXGD767bCee6vNVm5gBT@webmail.leidinger.net> From: Alexander Leidinger To: freebsd-fs@freebsd.org Subject: Re: zfs scrub enable by default References: In-Reply-To: Accept-Language: de,en Content-Type: multipart/signed; boundary="=_7LPHxqkS6ZS0wef0ywo1nZa"; protocol="application/pgp-signature"; micalg=pgp-sha1 MIME-Version: 1.0 X-Rspamd-Queue-Id: 4BTH894V1qz3dpw X-Spamd-Bar: --- X-Spamd-Result: default: False [-3.60 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; R_DKIM_ALLOW(-0.20)[leidinger.net:s=outgoing-alex]; NEURAL_HAM_MEDIUM(-0.96)[-0.959]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; MIME_GOOD(-0.20)[multipart/signed,text/plain]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-fs@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_HAM_LONG(-1.00)[-1.002]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[leidinger.net:+]; DMARC_POLICY_ALLOW(-0.50)[leidinger.net,quarantine]; NEURAL_HAM_SHORT(-0.54)[-0.535]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; ASN(0.00)[asn:34240, ipnet:89.238.64.0/18, country:DE]; RCVD_TLS_ALL(0.00)[]; RECEIVED_SPAMHAUS_PBL(0.00)[80.141.88.88:received] X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 15 Aug 2020 10:47:54 -0000 This message is in MIME format and has been PGP signed. --=_7LPHxqkS6ZS0wef0ywo1nZa Content-Type: text/plain; charset=utf-8; format=flowed; DelSp=Yes Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Quoting Matthew Ahrens via freebsd-fs (from=20=20 Tue,=204 Aug 2020 08:54:41 -0700): > This question was raised elsewhere, and I agree with this reply from Geor= ge > Wilson, my colleague and an expert in the i/o subsystems of ZFS as well a= s > having lots of experience with customers: > > Having scrubs enabled by default is a great idea but at Sun (and Delphix > too) we found that the impact was often too much for some > workloads/customers. This is the challenge we faced and why there was nev= er > a policy to enable it everywhere. We did explore ideas to make the impact > less and to be able to always scrub. Some of those ideas included periodi= c > or continuous scrubs where the impact could be reduced by only scrubbing > portions of the pool at a time, at a reduced i/o rate. At Delphix, we hav= e > investigated similar concepts and one of our interns prototyped one of th= e > ideas.Much has changed since the early scrub days and revisiting some of > the earlier ideas and investigating new ones is probably a good topic for > the community. I do think that just enabling scrub by default without > further enhancements would still be too impactful for some customers but > the concept definitely has merit. Does the zpool man-page come from OpenZFS, or is it a FreeBSD addition? The reason for this question is, that I had checked the content for=20=20 any=20mention of the FreeBSD periodic scripts. There is nothing=20=20 mentioned=20and I think it would be good to mention the periodic=20=20 scrubbing=20functionality of FreeBSD in there (back then when I wrote=20=20 the=20scrubbing part for "periodic daily" I added docs to the=20=20 periodic.conf=20man-page, but failed to mention it in the zpool man-page). If the zpool man-page comes from OpenZFS, what would be a good way to=20=20 mention=20such kind of functionality (I think we should mention that as=20= =20 part=20of periodic daily there is the possibility to scrub and that more=20= =20 docs=20is available in periodic.conf (daily_scrub_zfs_* variables))? Bye, Alexander. --=20 http://www.Leidinger.net=20Alexander@Leidinger.net: PGP 0x8F31830F9F2772BF http://www.FreeBSD.org netchild@FreeBSD.org : PGP 0x8F31830F9F2772BF --=_7LPHxqkS6ZS0wef0ywo1nZa Content-Type: application/pgp-signature Content-Description: Digitale PGP-Signatur Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJfN706AAoJEBINsJsD+NiGyngP/33EDD8FrsnYqs7OYmwOFKRt 9mShRR/zOeAOwYVP+W7bZpnzyOjh2y83vGOX3QgAYVXnqaxm4/p/FKtvPf4aeYXI sgcX/Z/zAQzWTPZLZtqrdW/Lbrgmcsr9l7NhklVHwHLxd5+OXusAEbGF3kycRLvV 5Yt6T+PmBMcvtcUvJ9MDfFEe++xP2cPHYtKZe2sH8auiJ7mCXLZmCLvFbTUWHi6x DKqNw9so6yb5ZADbI2PenwTZ4rCpwPeujtWIwh4Snn9XRjYHoK792W8eemo74Mgn nRCTO+xWIn8XqKPBzKel49FVsJEDd4EPEUayxOQcPomvkyp8vJBM0Xv4xhAOpSjh PKi+0O+P8BaF5dyAZu2k6GQQJq40ScJ8ygWt6qMle9kSLuk+yRCwA3bCofFqfcKn qyqj20z94/AblCLajcxwf9ZAZyOZrkCo7sMvqdHRool59fzb/SMeQgu93ZflcdFV ZpRqErsgsklxlNs4uiYMzrGkhY5KO1cji2+Pn7IxhVXO73biMR/d4V650+9/tRKv ZA2ME9LRVSV6qxDrHQGd/GT2ofJLnvzPgrb4yk4ru0uxfx8Fmrv0mh9VuTG2NYJ/ YiKuxUJZR+/xvIcEQijnPuFnU+q0dbwn2ZctGP2smkI/2KZgWZEiV5GdNgj11+cJ +a2ISR1IcDDJuHl6bjoH =Htzy -----END PGP SIGNATURE----- --=_7LPHxqkS6ZS0wef0ywo1nZa--