From tim.haley@oracle.com Mon Jul 26 07:39:20 2010 Received: from sunmail2sca.sfbay.sun.com (sunmail2sca.SFBay.Sun.COM [129.145.155.234]) by sac.sfbay.sun.com (8.13.8+Sun/8.13.8) with ESMTP id o6QEdKLw013393 for ; Mon, 26 Jul 2010 07:39:20 -0700 (PDT) Received: from brm-avmta-1.central.sun.com (brm-avmta-1.Central.Sun.COM [129.147.4.11]) by sunmail2sca.sfbay.sun.com (8.13.8+Sun/8.13.8/ENSMAIL,v2.4) with ESMTP id o6QEdJAG005331; Mon, 26 Jul 2010 07:39:19 -0700 (PDT) Received: from pmxchannel-daemon.brm-avmta-1.central.sun.com by brm-avmta-1.central.sun.com (Sun Java System Messaging Server 6.2-3.04 (built Jul 15 2005)) id <0L6600I0161JAR00@brm-avmta-1.central.sun.com>; Mon, 26 Jul 2010 08:39:19 -0600 (MDT) Received: from sca-ea-mail-4.sun.com ([192.18.43.22]) by brm-avmta-1.central.sun.com (Sun Java System Messaging Server 6.2-3.04 (built Jul 15 2005)) with ESMTP id <0L6600DQV61IQ660@brm-avmta-1.central.sun.com>; Mon, 26 Jul 2010 08:39:19 -0600 (MDT) Received: from acsinet15.oracle.com (acsinet15.oracle.com [141.146.126.227]) by sca-ea-mail-4.sun.com (8.13.6+Sun/8.12.9) with ESMTP id o6QEdIUQ017944; Mon, 26 Jul 2010 14:39:18 +0000 (GMT) Received: from acsmt355.oracle.com (acsmt355.oracle.com [141.146.40.155]) by acsinet15.oracle.com (Switch-3.4.2/Switch-3.4.1) with ESMTP id o6Q0LhHg023799; Mon, 26 Jul 2010 14:39:17 +0000 (GMT) Received: from abhmt012.oracle.com by acsmt354.oracle.com with ESMTP id 436717251280155104; Mon, 26 Jul 2010 07:38:24 -0700 Received: from [172.20.25.27] (/10.85.25.27) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 26 Jul 2010 07:38:24 -0700 Date: Mon, 26 Jul 2010 08:38:22 -0600 From: Tim Haley Subject: zpool import despite missing log [PSARC/2010/292 Self Review] To: PSARC-ext@sun.com Cc: zfs-team@sun.com Message-id: <4C4D9DDE.9040004@oracle.com> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7BIT X-PMX-Version: 5.4.1.325704 X-Source-IP: acsmt355.oracle.com [141.146.40.155] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090202.4C4D9E15.02C8:SCFMA4539814,ss=1,pt=113351,fgs=0 User-Agent: Mozilla/5.0 (X11; U; SunOS i86pc; en-US; rv:1.9.1.10) Gecko/20100621 Thunderbird/3.0.5 Status: RO Content-Length: 5433 I am sponsoring the following case for George Wilson. Requested binding is micro/patch. Since this is a straight-forward addition of a command line option, I think itqualifies for self review. If an ARC member disagrees, let me know and I'll convert to a fast-track. Template Version: @(#)sac_nextcase 1.70 03/30/10 SMI This information is Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. 1. Introduction 1.1. Project/Component Working Name: zpool import despite missing log 1.2. Name of Document Author/Supplier: Author: George Wilson 1.3 Date of This Document: 26 July, 2010 4. Technical Description OVERVIEW: ZFS maintains a GUID (global unique identifier) on each device and the sum of all GUIDs of a pool are stored into the ZFS uberblock. This sum is used to determine the availability of all vdevs within a pool when a pool is imported or opened. Pools which contain a separate intent log device (e.g. a slog) will fail to import when that device is removed or is otherwise unavailable. This proposal aims to address this particular issue. PROPOSED SOLUTION: This fast-track introduce a new command line flag to the 'zpool import' sub-command. This new option, '-m', allows pools to import even when a log device is missing. The contents of that log device are obviously discarded and the pool will operate as if the log device were offlined. MANPAGE DIFFS: zpool import [-o mntopts] [-p property=value] ... [-d dir | -c cachefile] - [-D] [-f] [-R root] [-n] [-F] -a + [-D] [-f] [-m] [-R root] [-n] [-F] -a zpool import [-o mntopts] [-o property=value] ... [-d dir | -c cachefile] - [-D] [-f] [-R root] [-n] [-F] pool |id [newpool] + [-D] [-f] [-m] [-R root] [-n] [-F] pool |id [newpool] zpool import [-o mntopts] [ -o property=value] ... [-d dir | - -c cachefile] [-D] [-f] [-n] [-F] [-R root] -a + -c cachefile] [-D] [-f] [-m] [-n] [-F] [-R root] -a Imports all pools found in the search directories. Identical to the previous command, except that all pools + -m + + Allows a pool to import when there is a missing log device EXAMPLES: 1). Configuration with a single intent log device: # zpool status tank pool: tank state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 c7t0d0 ONLINE 0 0 0 logs c5t0d0 ONLINE 0 0 0 errors: No known data errors # zpool import tank The devices below are missing, use '-m' to import the pool anyway: c5t0d0 [log] cannot import 'tank': one or more devices is currently unavailable # zpool import -m tank # zpool status tank pool: tank state: DEGRADED status: One or more devices could not be opened. Sufficient replicas exist for the pool to continue functioning in a degraded state. action: Attach the missing device and online it using 'zpool online'. see: http://www.sun.com/msg/ZFS-8000-2Q scan: none requested config: NAME STATE READ WRITE CKSUM tank DEGRADED 0 0 0 c7t0d0 ONLINE 0 0 0 logs 1693927398582730352 UNAVAIL 0 0 0 was /dev/dsk/c5t0d0 errors: No known data errors 2). Configuration with mirrored intent log device: # zpool add tank log mirror c5t0d0 c5t1d0 zroot@diskmonster:/dev/dsk# zpool status tank pool: tank state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM tank ONLINE 0 0 0 c7t0d0 ONLINE 0 0 0 logs mirror-1 ONLINE 0 0 0 c5t0d0 ONLINE 0 0 0 c5t1d0 ONLINE 0 0 0 errors: No known data errors # zpool import 429789444028972405 The devices below are missing, use '-m' to import the pool anyway: mirror-1 [log] c5t0d0 c5t1d0 # zpool import -m tank # zpool status tank pool: tank state: DEGRADED status: One or more devices could not be opened. Sufficient replicas exist for the pool to continue functioning in a degraded state. action: Attach the missing device and online it using 'zpool online'. see: http://www.sun.com/msg/ZFS-8000-2Q scan: none requested config: NAME STATE READ WRITE CKSUM tank DEGRADED 0 0 0 c7t0d0 ONLINE 0 0 0 logs mirror-1 UNAVAIL 0 0 0 insufficient replicas 46385995713041169 UNAVAIL 0 0 0 was /dev/dsk/c5t0d0 13821442324672734438 UNAVAIL 0 0 0 was /dev/dsk/c5t1d0 errors: No known data errors 6. Resources and Schedule 6.4. Steering Committee requested information 6.4.1. Consolidation C-team Name: ON 6.5. ARC review type: Automatic 6.6. ARC Exposure: open