From owner-freebsd-fs@freebsd.org Fri Mar 26 12:41:12 2021 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 30E205BE26A; Fri, 26 Mar 2021 12:41:12 +0000 (UTC) (envelope-from mchouque@thi.eu.com) Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4F6M5z62wpz4d1v; Fri, 26 Mar 2021 12:41:11 +0000 (UTC) (envelope-from mchouque@thi.eu.com) X-Originating-IP: 62.210.143.248 Received: from weirdfishes.localdomain (62-210-143-248.rev.poneytelecom.eu [62.210.143.248]) (Authenticated sender: m@thi.eu.com) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id 9959860002; Fri, 26 Mar 2021 12:41:08 +0000 (UTC) Received: by weirdfishes.localdomain (Postfix, from userid 1000) id 48BB17203B9D5; Fri, 26 Mar 2021 13:41:08 +0100 (CET) Date: Fri, 26 Mar 2021 13:41:08 +0100 From: Mathieu Chouquet-Stringer To: Michael Gmelin Cc: Matt Churchyard , "freebsd-fs@freebsd.org" , current@freebsd.org Subject: Re: Scrub incredibly slow with 13.0-RC3 (as well as RC1 & 2) Message-ID: References: <202103221515.12MFFHRK015188@higson.cam.lispworks.com> <202103241230.12OCUqur030001@higson.cam.lispworks.com> <33eb78e2de404a77b271880dbee4c22e@SERVER.ad.usd-group.com> <20210326132945.3274687e@bsd64.grem.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210326132945.3274687e@bsd64.grem.de> X-Rspamd-Queue-Id: 4F6M5z62wpz4d1v X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; TAGGED_FROM(0.00)[freebsd]; REPLY(-4.00)[] X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Mar 2021 12:41:12 -0000 On Fri, Mar 26, 2021 at 01:29:45PM +0100, Michael Gmelin wrote: > Does tuning of > > - vfs.zfs.scrub_delay > - vfs.zfs.resilver_min_time_ms > - vfs.zfs.resilver_delay > > make a difference? Only vfs.zfs.resilver_min_time_ms exists in 13 it seems. The default values is 3000 but doubling it to 6000 doesn't change anything. And that could make sense because it seems I'm often cpu bound as I see the following in top (-SH): PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND 31 root -8 - 0B 3984K CPU12 12 758:07 99.65% zfskern{dsl_scan_iss_0} And that's on an Intel(R) Xeon(R) CPU E5-2696 v2 @ 2.50GHz with a turbo @ 3.50GHz... Disks are busy roughly between 30 to 50% of the time: extended device statistics device r/s w/s kr/s kw/s ms/r ms/w ms/o ms/t qlen %b da2 1520 0 34974.1 0.0 0 0 0 0 1 31 da3 1469 0 35030.3 0.0 0 0 0 0 0 32 da4 1317 0 35106.6 0.0 0 0 0 0 0 42 da6 1293 0 35094.5 0.0 0 0 0 0 0 36 da7 1466 0 35032.3 0.0 0 0 0 0 0 31 da8 0 1303 0.0 34917.9 0 0 0 0 0 43 da9 1396 0 35046.4 0.0 0 0 0 0 1 34 da10 1393 0 35062.4 0.0 0 0 0 0 0 32 da8 is the disk being resilvered. -- Mathieu Chouquet-Stringer The sun itself sees not till heaven clears. -- William Shakespeare --