From owner-freebsd-fs@FreeBSD.ORG Tue Sep 28 02:38:15 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E21DD106566B for ; Tue, 28 Sep 2010 02:38:15 +0000 (UTC) (envelope-from bsdunix44@gmail.com) Received: from mail-yx0-f182.google.com (mail-yx0-f182.google.com [209.85.213.182]) by mx1.freebsd.org (Postfix) with ESMTP id 9B9E38FC0C for ; Tue, 28 Sep 2010 02:38:15 +0000 (UTC) Received: by yxn35 with SMTP id 35so2200909yxn.13 for ; Mon, 27 Sep 2010 19:38:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:from:to :content-type:content-transfer-encoding:mime-version:subject:date :x-mailer; bh=yjWxlVVcQdNyYIImg2i8flXoTwAmx9ObTJSDPT6IMJ8=; b=dkndVuG5ykpA3orIu/+nkdaBYJZWjoyTSQ40i7qlI7JcTbgU5DnsSwUNYl1va87VKL eBO7wMJiUf9Rr83whdlmdJozKuiuaQRwzwmCFWTvYlnKxyaGS0jobQdN/aNTM0BXD+m9 aIF0aVUN78pDEK11NTrMESDBpuvPWgwotZvHM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:from:to:content-type:content-transfer-encoding :mime-version:subject:date:x-mailer; b=ga6zFZikABErEfuTkuiLbua12xacL2F5L7lm6j3mGy58Rr9M/gBugZarr+pYTZn0FQ JJH0i92RpqwiwSweInhBaLH6QWhmKViiLxiF6GakLsmF3jOcFPEmBYvezX4Flw7LG+ms vXlXX1pxG1U4tCnNZrj3msSw+PMcrWJb6rUV8= Received: by 10.150.12.9 with SMTP id 9mr10106824ybl.213.1285641492895; Mon, 27 Sep 2010 19:38:12 -0700 (PDT) Received: from [192.168.1.4] (ip98-164-15-137.ks.ks.cox.net [98.164.15.137]) by mx.google.com with ESMTPS id u42sm9966157yba.12.2010.09.27.19.38.11 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 27 Sep 2010 19:38:11 -0700 (PDT) Message-Id: <246F9240-10FE-4BD6-B72B-D374F9BB1FC9@gmail.com> From: Chris Watson To: freebsd-fs@freebsd.org Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v936) Date: Mon, 27 Sep 2010 21:38:04 -0500 X-Mailer: Apple Mail (2.936) Subject: zdb and zpool status inconsistency question... X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Sep 2010 02:38:16 -0000 Apologies if this is common knowledge but I am confused about that output of zdb and zpool status. Running a: priyanka# zdb data version=14 name='data' state=0 txg=23 pool_guid=7697236283104447800 hostid=1421614680 hostname='priyanka.open-systems.net' vdev_tree type='root' id=0 guid=7697236283104447800 children[0] type='mirror' id=0 guid=13989036133163076272 metaslab_array=26 metaslab_shift=33 ashift=9 asize=1000199946240 is_log=0 children[0] type='disk' id=0 guid=15173803910329500054 path='/dev/ada2' whole_disk=0 children[1] type='disk' id=1 guid=17277025077506889808 path='/dev/ada3' whole_disk=0 children[1] type='mirror' id=1 guid=5773672864445772603 metaslab_array=23 metaslab_shift=33 ashift=9 asize=1000199946240 is_log=0 children[0] type='disk' id=0 guid=2441189965306101196 path='/dev/ada4' whole_disk=0 children[1] type='disk' id=1 guid=6210476332908709518 path='/dev/ada5' whole_disk=0 Uberblock magic = 0000000000bab10c version = 14 txg = 11387 guid_sum = 13222208345635842403 timestamp = 1285637267 UTC = Mon Sep 27 20:27:47 2010 Dataset mos [META], ID 0, cr_txg 4, 1.06M, 44 objects Dataset data/Aperture [ZPL], ID 31, cr_txg 37, 47.9G, 17596 objects Dataset data [ZPL], ID 16, cr_txg 1, 19.0K, 5 objects [...] capacity operations bandwidth ---- errors ---- description used avail read write read write read write cksum data 47.9G 1.77T 292 0 32.6M 0 0 0 2 mirror 23.9G 904G 146 0 16.3M 0 0 0 6 /dev/ada2 141 0 16.5M 0 0 0 6 /dev/ada3 141 0 16.5M 0 0 0 6 mirror 23.9G 904G 146 0 16.3M 0 0 0 2 /dev/ada4 141 0 16.5M 0 0 0 2 /dev/ada5 141 0 16.5M 0 0 0 2 priyanka# produces cksum errors of 2,6,6,6,2,2,2 respectively. While a: priyanka# zpool status -v data pool: data state: ONLINE scrub: scrub completed after 0h6m with 0 errors on Mon Sep 27 20:22:10 2010 config: NAME STATE READ WRITE CKSUM data ONLINE 0 0 0 mirror ONLINE 0 0 0 ada2 ONLINE 0 0 0 ada3 ONLINE 0 0 0 mirror ONLINE 0 0 0 ada4 ONLINE 0 0 0 ada5 ONLINE 0 0 0 errors: No known data errors priyanka# So the two questions I have that I don't understand are the following: 1) Why does zdb report cksum errors while zpool status does not? 2) Assuming zdb is correct, shouldnt the errors from zdb for the pool "data" be 8 instead of 2? Since the first mirror has 6 and the second mirror has 2 cksum errors? The zdb man page is pretty sparse. And I know it's not meant to be run by the average joe. I'm just trying to learn ZFS as thoroughly as I can. So while I have a test system I am trying many configs and options to learn how it works and why. And the above inconsistency confused me. Again apologies if this is covered elsewhere. Thanks for any schooling about the above! Chris