From owner-freebsd-fs@freebsd.org Tue Apr 26 13:17:18 2016 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 80366B1CF81 for ; Tue, 26 Apr 2016 13:17:18 +0000 (UTC) (envelope-from jg@internetx.com) Received: from mx1.internetx.com (mx1.internetx.com [62.116.129.39]) by mx1.freebsd.org (Postfix) with ESMTP id 45BDB1F2D for ; Tue, 26 Apr 2016 13:17:18 +0000 (UTC) (envelope-from jg@internetx.com) Received: from localhost (localhost [127.0.0.1]) by mx1.internetx.com (Postfix) with ESMTP id BD18C4C4C820; Tue, 26 Apr 2016 15:09:31 +0200 (CEST) X-Virus-Scanned: InterNetX GmbH amavisd-new at ix-mailer.internetx.de Received: from mx1.internetx.com ([62.116.129.39]) by localhost (ix-mailer.internetx.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qCbPEnV2sgFq; Tue, 26 Apr 2016 15:09:26 +0200 (CEST) Received: from [192.168.100.26] (pizza.internetx.de [62.116.129.3]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mx1.internetx.com (Postfix) with ESMTPSA id EE0594C4C79A; Tue, 26 Apr 2016 15:09:25 +0200 (CEST) Subject: Re: How to speed up slow zpool scrub? References: <571F62AD.6080005@quip.cz> To: Miroslav Lachman <000.fbsd@quip.cz>, freebsd-fs@freebsd.org Reply-To: jg@internetx.com From: InterNetX - Juergen Gotteswinter Message-ID: <571F687D.8040103@internetx.com> Date: Tue, 26 Apr 2016 15:09:17 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <571F62AD.6080005@quip.cz> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Apr 2016 13:17:18 -0000 to speed up the scrub itself you can try sysctl -w vfs.zfs.scrub_delay = 4 (default, 0 means higher prio) but be careful as this can cause a serious performance impact, the value can be changed on the fly your pool is raidz, mirror ? dedup is hopefully disabled? Am 4/26/2016 um 2:44 PM schrieb Miroslav Lachman: > Hi, > > is there any way to make zpool scrub faster? > We have one older machine with CPU Pentium(R) Dual E2160 @1.80GHz, 5GB > of RAM and 4x 4TB HDDs. It is just a storage for backups for about 20 > machines. > Scrub is scheduled from periodic each 30 days but it takes about 4 days > to complete and everything during scrub is slow. Backups takes 8 hours > instead of 5 (made by rsync), deleting of old files is even more slower. > > The backups are made every night from the midnight to morning, the > machine is idle for the rest of the day. > > Is there any tuning to make scrub faster in this idle time? > Or is it better to do it other way - slower scrub with even lower > priority taking for about one week but not affecting time of normal > operations? (is it dangerous to have scrub running this long or reboot > machine during the scrub?) > > I have a performance graphs of this machine and CPU is about 70% idle > during scrub, but hard drives are busy 75% (according to iostat) > > FreeBSD 10.3-RELEASE amd64 GENERIC > > Miroslav Lachman > _______________________________________________ > freebsd-fs@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org"