From owner-freebsd-fs@freebsd.org Sat Feb 20 00:12:14 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 EC938AAEA10 for ; Sat, 20 Feb 2016 00:12:14 +0000 (UTC) (envelope-from michelle@sorbs.net) Received: from hades.sorbs.net (mail.sorbs.net [67.231.146.200]) by mx1.freebsd.org (Postfix) with ESMTP id DEEA585D; Sat, 20 Feb 2016 00:12:14 +0000 (UTC) (envelope-from michelle@sorbs.net) MIME-version: 1.0 Content-transfer-encoding: 8BIT Content-type: text/plain; charset=ISO-8859-1 Received: from isux.com (firewall.isux.com [213.165.190.213]) by hades.sorbs.net (Oracle Communications Messaging Server 7.0.5.29.0 64bit (built Jul 9 2013)) with ESMTPSA id <0O2T00FBMKW29Q00@hades.sorbs.net>; Fri, 19 Feb 2016 16:19:18 -0800 (PST) Message-id: <56C7AF59.6060600@sorbs.net> Date: Sat, 20 Feb 2016 01:12:09 +0100 From: Michelle Sullivan User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.24) Gecko/20100301 SeaMonkey/1.1.19 To: Don Lewis Cc: n.corvini@gmail.com, freebsd-fs@freebsd.org Subject: Re: Zfs heavy io writing | zfskern txg_thread_enter References: <201602192250.u1JMoLjQ079393@gw.catspoiler.org> In-reply-to: <201602192250.u1JMoLjQ079393@gw.catspoiler.org> X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Feb 2016 00:12:15 -0000 Don Lewis wrote: > On 19 Feb, Niccolò Corvini wrote: > >> Hi, first time here! >> We are having a problem with a server running FreeBsd 9.1 with ZFS on a >> single sata drive. Since a few days ago, in the morning the system becomes >> really slow due of a really heavy io writing. We investigated and we think >> it might start at night, maybe correlated to to crondaily (standard) but we >> are not sure. After a few hours the situation returns to normal. >> Any help is much appreciated >> The machine is a Intel Xeon E5-2620 with 36GB of RAM, the HDD is a 2TB an >> is half full. >> > > The only way that you should get a lot of write traffic during the daily > periodic runs is if atime updates are enabled. I don't know what the > default was for FreeBSD 9.1, but recent versions of FreeBSD disable > atime updates on ZFS everywhere except /var/mail. What does > zfs get -o all atime > say? > On 9.2 and 9.3 it seems the default is (respectively): NAME PROPERTY VALUE RECEIVED SOURCE storage atime on - default NAME PROPERTY VALUE RECEIVED SOURCE VirtualDisks atime on - default VirtualDisks/FreeBSD10.0amd64-Build atime - - - VirtualDisks/FreeBSD10.0amd64-OS atime - - - VirtualDisks/FreeBSD10.1amd64-Build atime - - - VirtualDisks/FreeBSD10.1amd64-OS atime - - - VirtualDisks/FreeBSD8.4-Build atime - - - VirtualDisks/FreeBSD8.4-OS atime - - - VirtualDisks/FreeBSD9.0-Build atime - - - VirtualDisks/FreeBSD9.0-OS atime - - - VirtualDisks/FreeBSD9.1-Build atime - - - VirtualDisks/FreeBSD9.1-OS atime - - - VirtualDisks/FreeBSD9.2amd64-Build atime - - - VirtualDisks/FreeBSD9.2amd64-OS atime - - - VirtualDisks/FreeBSD9.2i386-Build atime - - - VirtualDisks/FreeBSD9.2i386-OS atime - - - VirtualDisks/FreeBSD9.3amd64-Build atime - - - VirtualDisks/FreeBSD9.3amd64-OS atime - - - VirtualDisks/FreeBSD9.3i386-Build atime - - - VirtualDisks/FreeBSD9.3i386-OS atime - - - sorbs atime on - default sorbs/VirtualDisks atime - - - It's probably the same for Niccolò on the 9.1 system. Best regards, Michelle -- Michelle Sullivan http://www.mhix.org/