From owner-freebsd-questions@FreeBSD.ORG Sat Dec 9 21:31:11 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 5DEE516A412 for ; Sat, 9 Dec 2006 21:31:11 +0000 (UTC) (envelope-from fk@zepher.dyndns.org) Received: from rosy.dyndns.org (softbank220038116012.bbtec.net [220.38.116.12]) by mx1.FreeBSD.org (Postfix) with SMTP id 83D9143CB3 for ; Sat, 9 Dec 2006 21:30:02 +0000 (GMT) (envelope-from fk@zepher.dyndns.org) Received: (qmail 52714 invoked from network); 9 Dec 2006 21:18:28 -0000 Received: from unknown (HELO localhost) (127.0.0.1) by localhost with SMTP; 9 Dec 2006 21:18:28 -0000 To: freebsd-questions@freebsd.org X-Mailer: Mew version 1.94.2 on Emacs 19.34 / Mule 2.3 (SUETSUMUHANA) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20061210061828K.fk@zepher.dyndns.org> Date: Sun, 10 Dec 2006 06:18:28 +0900 From: FK X-Dispatcher: imput version 20000228(IM140) Lines: 108 Subject: How can I fix "Cannot find file system superblock" problem? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Dec 2006 21:31:11 -0000 Dear list members, How can I fix "Cannot find file system superblock" problem? I thought there would be a solution on the Internet, and googled but could not find one yet. I hope you would have some hints. Thank you. Background: FreeBSD6.0-RELEASE. #disklabel /dev/da0s2 # /dev/da0s2: 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 18994687 524288 4.2BSD 2048 16384 28552 b: 524288 0 swap c: 19518975 0 unused 0 0 # "raw" part, don't edit What I did: #fsck_ffs /dev/da0s2a ** /dev/da0s2a Cannot find file system superblock LOOK FOR ALTERNATE SUPERBLOCKS? [yn] y 32 is not a file system superblock SEARCH FOR ALTERNATE SUPER-BLOCK FAILED. YOU MUST USE THE -b OPTION TO FSCK TO SPECIFY THE LOCATION OF AN ALTERNATE SUPER-BLOCK TO SUPPLY NEEDED INFORMATION; SEE fsck(8). #newfs -N /dev/da0s2a /dev/da0s2a: 9274.7MB (18994684 sectors) block size 16384, fragment size 2048 using 51 cylinder groups of 183.77MB, 11761 blks, 23552 inodes. super-block backups (for fsck -b #) at: 160, 376512, 752864, 1129216, 1505568, 1881920, 2258272, 2634624, 3010976, 3387328, 3763680, 4140032, 4516384, 4892736, 5269088, 5645440, 6021792, 6398144, 6774496, 7150848, 7527200, 7903552, 8279904, 8656256, 9032608, 9408960, 9785312, 10161664, 10538016, 10914368, 11290720, 11667072, 12043424, 12419776, 12796128, 13172480, 13548832, 13925184, 14301536, 14677888, 15054240, 15430592, 15806944, 16183296, 16559648, 16936000, 17312352, 17688704, 18065056, 18441408, 18817760, 19194112 I "fsck_ufs"ed every alternative superblock like below, but the program complained they are not superblocks. # fsck_ufs -b 160 /dev/da0s2 Alternate super block location: 160 ** /dev/da0s2 160 is not a file system superblock # fsck_ufs -b 376512 /dev/da0s2 Alternate super block location: 376512 ** /dev/da0s2 376512 is not a file system superblock # fsck_ufs -b 752864 /dev/da0s2 Alternate super block location: 752864 ** /dev/da0s2 752864 is not a file system superblock -- snip -- # fsck_ufs -b 18441408 /dev/da0s2 Alternate super block location: 18441408 ** /dev/da0s2 18441408 is not a file system superblock # fsck_ufs -b 18817760 /dev/da0s2 Alternate super block location: 18817760 ** /dev/da0s2 18817760 is not a file system superblock # fsck_ufs -b 19194112 /dev/da0s2 Alternate super block location: 19194112 ** /dev/da0s2 19194112 is not a file system superblock If alternatives are all copies of the master, they must have the same contents. I checked and found they are equal. # dd if=/dev/da0s2a skip=160 bs=512 count=16 of=sb1 16+0 records in 16+0 records out 8192 bytes transferred in 0.013373 secs (612571 bytes/sec) # dd if=/dev/da0s2a skip=376512 bs=512 count=16 of=sb2 16+0 records in 16+0 records out 8192 bytes transferred in 0.425421 secs (19256 bytes/sec) # dd if=/dev/da0s2a skip=752864 bs=512 count=16 of=sb3 16+0 records in 16+0 records out 8192 bytes transferred in 0.018652 secs (439198 bytes/sec) #diff -s sb1 sb2 Files sb1 and sb2 are identical #diff -s sb1 sb3 Files sb1 and sb3 are identical #diff -s sb2 sb3 Files sb2 and sb3 are identical If you have any suggestions, I really aprreciate. Thank you. -- FK.