From owner-freebsd-fs@FreeBSD.ORG Tue Mar 17 01:54:50 2015 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id BA6EA91F for ; Tue, 17 Mar 2015 01:54:50 +0000 (UTC) Received: from woozle.rinet.ru (woozle.rinet.ru [195.54.192.68]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 38C9E96B for ; Tue, 17 Mar 2015 01:54:49 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by woozle.rinet.ru (8.14.5/8.14.5) with ESMTP id t2H1qAVs085728; Tue, 17 Mar 2015 04:52:10 +0300 (MSK) (envelope-from marck@rinet.ru) Date: Tue, 17 Mar 2015 04:52:10 +0300 (MSK) From: Dmitry Morozovsky To: Steven Hartland Subject: Re: ZFS doing background writes? In-Reply-To: <55076B84.0@multiplay.co.uk> Message-ID: References: <55076B84.0@multiplay.co.uk> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) X-NCC-RegID: ru.rinet X-OpenPGP-Key-ID: 6B691B03 MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (woozle.rinet.ru [0.0.0.0]); Tue, 17 Mar 2015 04:53:17 +0300 (MSK) Cc: freebsd-fs@freebsd.org X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Mar 2015 01:54:50 -0000 On Mon, 16 Mar 2015, Steven Hartland wrote: > yes exactly that its defined by vfs.zfs.txg.timeout. Well, but what data (modulo atimes, which I presume OP had turned off before) are written? > > On 16/03/2015 23:09, Dirk E wrote: > > I'm curious now; does ZFS do any I/O on the background? > > > > Because i'm getting periodic writes from ZFS to my disks, beginning right > > after i import the pool. > > > > Even going to single user mode does not help; zpool iostat -v 1 still shows > > the writes with static 5 second interval. > > > > What would cause this behaviour? I encountered it with both 10.1-RELEASE and > > a very recent HEAD. -- Sincerely, D.Marck [DM5020, MCK-RIPE, DM3-RIPN] [ FreeBSD committer: marck@FreeBSD.org ] ------------------------------------------------------------------------ *** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck@rinet.ru *** ------------------------------------------------------------------------