From owner-freebsd-fs@FreeBSD.ORG Mon Mar 16 23:10:16 2015 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 66DCCB63 for ; Mon, 16 Mar 2015 23:10:16 +0000 (UTC) Received: from DUB004-OMC4S18.hotmail.com (dub004-omc4s18.hotmail.com [157.55.2.93]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (Client CN "*.outlook.com", Issuer "MSIT Machine Auth CA 2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C39686A1 for ; Mon, 16 Mar 2015 23:10:15 +0000 (UTC) Received: from DUB131-W44 ([157.55.2.73]) by DUB004-OMC4S18.hotmail.com over TLS secured channel with Microsoft SMTPSVC(7.5.7601.22751); Mon, 16 Mar 2015 16:09:05 -0700 X-TMN: [TwfVb+iKj5O1m7stWlXF3Meo2ZYAf6sM] X-Originating-Email: [cipher_nl@hotmail.com] Message-ID: From: Dirk E To: "freebsd-fs@FreeBSD.org" Subject: ZFS doing background writes? Date: Tue, 17 Mar 2015 00:09:05 +0100 Importance: Normal Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginalArrivalTime: 16 Mar 2015 23:09:05.0829 (UTC) FILETIME=[33473D50:01D0603E] 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: Mon, 16 Mar 2015 23:10:16 -0000 I'm curious now=3B does ZFS do any I/O on the background?=0A= =0A= Because i'm getting periodic writes from ZFS to my disks=2C beginning right= after i import the pool.=0A= =0A= Even going to single user mode does not help=3B zpool iostat -v 1 still sho= ws the writes with static 5 second interval.=0A= =0A= What would cause this behaviour? I encountered it with both 10.1-RELEASE an= d a very recent HEAD.=0A= =