From owner-freebsd-questions Wed Mar 5 10:37:37 2003 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 369EB37B401 for ; Wed, 5 Mar 2003 10:37:35 -0800 (PST) Received: from hauptpostamt.charite.de (hauptpostamt.charite.de [193.175.66.220]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7DF6443F85 for ; Wed, 5 Mar 2003 10:37:34 -0800 (PST) (envelope-from alexander.haderer@charite.de) Received: from postamt1.charite.de (postamt1.charite.de [193.175.66.246]) by hauptpostamt.charite.de (Postfix) with ESMTP id EED2F15C010; Wed, 5 Mar 2003 19:37:31 +0100 (CET) Received: from chaplin.charite.de (chaplin.str.charite.de [192.168.202.88]) by postamt1.charite.de (Postfix) with ESMTP id C3169633B3; Wed, 5 Mar 2003 19:37:31 +0100 (CET) Message-Id: <5.2.0.9.1.20030305190047.00b19d80@postamt1.charite.de> X-Sender: afrika@postamt1.charite.de X-Mailer: QUALCOMM Windows Eudora Version 5.2.0.9 Date: Wed, 05 Mar 2003 19:33:04 +0100 To: freebsd-questions@FreeBSD.ORG From: Alexander Haderer Subject: vinum: low level access to subdisks / drives Cc: Dirk Emmel In-Reply-To: <5.2.0.9.2.20030305114541.00bd5cb8@mail.servplex.com> References: <200303051245.28192.taxman@acd.net> <5.2.0.9.2.20030305083743.00bcfc80@mail.servplex.com> <3E4A973500003B77@cpfe6.be.tisc.dk> <5.2.0.9.2.20030305083743.00bcfc80@mail.servplex.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Virus-Scanned: by amavisd-new Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Hello, Here is a vinum question. Assume this setup: Two partitions ad0s1e and ad2s1e of type vinum with the same size. vinum is set up to use this disks as RAID 1 (mirror): drive drive0 device /dev/ad0s1e drive drive2 device /dev/ad2s1e volume mirr plex org concat sd len 0s drive disk0 plex org concat sd len 0s drive disk2 newfs has been done and the /dev/vinum/mirr is mounted to /mirr with rw access. Everything is working without problem. Because we do not rely on the harddisks and the files at /mirr are accessed seldom and random, we want to check, if all sectors of the disks ad0 and ad2 are readable without problem. To do so, we want to run a nightly low priority cron job that tries to read all sectors of a disk without further analyzing the data read. The "result" of a failed read (hard disk failure) will be a kernel message in /var/log/messages, which we monitor 24x7 a day. Lets say we do dd for reading the sectors: dd if=/dev/ad0s1 of=/dev/zero bs=1024k Questions: 1. Will this conflict with vinum or its internal (kernel) data structures when vinum is running the same time with all components of the RAID 'up'? 2. Will this conflict with parallel read/write access to /mirr ? 3. Should we use "dd if=/dev/vinum/sd/mirr.p0.s0 ..." instead of /dev/ad0s1e ? with best regards Alexander -- Alexander Haderer Charite Berlin - Germany To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message