1，一服务器/dev/sdb文件系统损坏，重启后系统启不来，进入单用户模式fsck无法修复，把/etc/fstab中的/dev/sdb注释掉后，系统成功起来。

2，mount挂载/dev/sdb提示bad superblock错误，无法正常挂载：[root@localhost ~]# mount /dev/sdb /test

mount: wrong fs type, bad option, bad superblock on /dev/sdb,

or too many mounted file systems

3，尝试直接指定备用超级块来挂载分区。通过mkfs -n可以查看到备份超级块的位置：[root@localhost ~]# mkfs.ext3 -n /dev/sdb

mke2fs 1.35 (28-Feb-2004)

/dev/sdb is entire device, not just one partition!

Proceed anyway? (y,n) y

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

365854720 inodes, 731688960 blocks

36584448 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=4294967296

22330 block groups

32768 blocks per group, 32768 fragments per group

16384 inodes per group

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,

4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,

102400000, 214990848, 512000000, 550731776, 644972544也可以通过dumpe2fs查看备份超级块的位置：[root@localhost ~]# dumpe2fs /dev/sdb | grep –before-context=1 superblock

dumpe2fs 1.35 (28-Feb-2004)

Group 0: (Blocks 0-32767)

Primary superblock at 0, Group deｓｃｒｉｐｔors at 1-175

–

Group 1: (Blocks 32768-65535)

Backup superblock at 32768, Group deｓｃｒｉｐｔors at 32769-32943

–

Group 3: (Blocks 98304-131071)

Backup superblock at 98304, Group deｓｃｒｉｐｔors at 98305-98479

–

Group 5: (Blocks 163840-196607)

Backup superblock at 163840, Group deｓｃｒｉｐｔors at 163841-164015

–

Group 7: (Blocks 229376-262143)

Backup superblock at 229376, Group deｓｃｒｉｐｔors at 229377-229551

–

Group 9: (Blocks 294912-327679)

Backup superblock at 294912, Group deｓｃｒｉｐｔors at 294913-295087

–

Group 25: (Blocks 819200-851967)

Backup superblock at 819200, Group deｓｃｒｉｐｔors at 819201-819375

–

Group 27: (Blocks 884736-917503)

Backup superblock at 884736, Group deｓｃｒｉｐｔors at 884737-884911

–

Group 49: (Blocks 1605632-1638399)

Backup superblock at 1605632, Group deｓｃｒｉｐｔors at 1605633-1605807

–

Group 81: (Blocks 2654208-2686975)

Backup superblock at 2654208, Group deｓｃｒｉｐｔors at 2654209-2654383

–

Group 125: (Blocks 4096000-4128767)

Backup superblock at 4096000, Group deｓｃｒｉｐｔors at 4096001-4096175

–

Group 243: (Blocks 7962624-7995391)

Backup superblock at 7962624, Group deｓｃｒｉｐｔors at 7962625-7962799

4，用查看到的备份超级块来挂载/dev/sdb，也无法成功：[root@localhost ~]# mount -o sb=32768 /dev/sdb /test

mount: wrong fs type, bad option, bad superblock on /dev/sdb,

or too many mounted file systems分区情况如下：[root@localhost ~]# fdisk -l

Disk /dev/sda: 998.9 GB, 998999326720 bytes

255 heads, 63 sectors/track, 121454 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           1          16      128488+  83  Linux

/dev/sda2              17        6390    51199155   83  Linux

/dev/sda3            6391       12764    51199155   83  Linux

/dev/sda4           12765      121454   873052425    5  Extended

/dev/sda5           12765       13796     8289508+  82  Linux swap

/dev/sda6           13797      121454   864762853+  83  Linux

Disk /dev/sdb: 2996.9 GB, 2996997980160 bytes

255 heads, 63 sectors/track, 364364 cylinders

Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdb doesn’t contain a valid partition table

[root@localhost ~]# parted /dev/sdb

GNU Parted 1.6.19

Copyright (C) 1998 - 2004 Free Software Foundation, Inc.

This program is free software, covered by the GNU General Public License.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

Using /dev/sdb

(parted) print

Disk geometry for /dev/sdb: 0.000-2858160.000 megabytes

Disk label type: loop

Minor    Start       End     Filesystem  Flags

1          0.000 2858160.000  ext3

(parted) quit

Information: Don’t forget to update /etc/fstab, if necessary.

5，尝试用备份超级块去fsck修复分区，报“illegal bitmap block”错误，也无法成功：[root@localhost ~]# fsck.ext3 -b 32768 /dev/sdb

e2fsck 1.35 (28-Feb-2004)

Block bitmap for group 4992 is not in group.  (block 809140608)

Relocate? yes

Inode bitmap for group 4992 is not in group.  (block 5385)

Relocate? yes

Inode table for group 4992 is not in group.  (block 1295485238)

WARNING: SEVERE DATA LOSS POSSIBLE.

Relocate? yes

Block bitmap for group 4993 is not in group.  (block 0)

Relocate? yes

Inode bitmap for group 4993 is not in group.  (block 0)

Relocate? yes

Inode bitmap for group 21631 is not in group.  (block 171349112)

Relocate? cancelled!

Inode table for group 21631 is not in group.  (block 0)

WARNING: SEVERE DATA LOSS POSSIBLE.

Relocate? cancelled!

fsck.ext3: e2fsck_read_bitmaps: illegal bitmap block(s) for /dev/sdb

[root@localhost ~]# fsck.ext3 -b 163840 /dev/sdb

e2fsck 1.35 (28-Feb-2004)

Block bitmap for group 4992 is not in group.  (block 809140608)

Relocate? yes

Inode bitmap for group 4992 is not in group.  (block 5385)

Relocate? cancelled!

Inode table for group 4992 is not in group.  (block 1295485238)

WARNING: SEVERE DATA LOSS POSSIBLE.

Relocate? cancelled!

Inode bitmap for group 21631 is not in group.  (block 171349112)

Relocate? cancelled!

Inode table for group 21631 is not in group.  (block 0)

WARNING: SEVERE DATA LOSS POSSIBLE.

Relocate? cancelled!

fsck.ext3: e2fsck_read_bitmaps: illegal bitmap block(s) for /dev/sdb

6，直接fsck -y修复分区，也是报一样的错误：[root@localhost ~]# fsck.ext3 -y /dev/sdb

e2fsck 1.35 (28-Feb-2004)

Group deｓｃｒｉｐｔors look bad… trying backup blocks…

Block bitmap for group 4992 is not in group.  (block 809140608)

Relocate? yes

Inode bitmap for group 4992 is not in group.  (block 5385)

Relocate? yes

Inode table for group 4992 is not in group.  (block 1295485238)

WARNING: SEVERE DATA LOSS POSSIBLE.

Relocate? yes

Block bitmap for group 4993 is not in group.  (block 0)

Relocate? yes

Inode bitmap for group 4993 is not in group.  (block 0)

Relocate? yes

Inode table for group 4993 is not in group.  (block 567580784)

WARNING: SEVERE DATA LOSS POSSIBLE.

Relocate? yes

Block bitmap for group 4994 is not in group.  (block 0)

Relocate? yes

Block bitmap for group 21630 is not in group.  (block 0)

Relocate? yes

Inode bitmap for group 21630 is not in group.  (block 0)

Relocate? yes

Inode table for group 21630 is not in group.  (block 0)

WARNING: SEVERE DATA LOSS POSSIBLE.

Relocate? yes

Block bitmap for group 21631 is not in group.  (block 0)

Relocate? yes

Inode bitmap for group 21631 is not in group.  (block 171349112)

Relocate? yes

Inode table for group 21631 is not in group.  (block 0)

WARNING: SEVERE DATA LOSS POSSIBLE.

Relocate? yes

fsck.ext3: e2fsck_read_bitmaps: illegal bitmap block(s) for /dev/sdb

7，用mke2fs -S重新生成超级块(注：此为实在没办法才执行的，不成功的话则全部数据会有丢失的可能)，修复成功了！！[root@localhost ~]# mke2fs -S /dev/sdb

mke2fs 1.35 (28-Feb-2004)

/dev/sdb is entire device, not just one partition!

Proceed anyway? (y,n) y

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

365854720 inodes, 731688960 blocks

36584448 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=4294967296

22330 block groups

32768 blocks per group, 32768 fragments per group

16384 inodes per group

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,

4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,

102400000, 214990848, 512000000, 550731776, 644972544

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 39 mounts or

180 days, whichever comes first.  Use tune2fs -c or -i to override.

8，终于可以将分区挂载上了：[root@localhost ~]# mount /dev/sdb /test

9，用tune2fs -l查看/dev/sdb，发现状态为：not clean with errors，浏览文件发现其中还是有很多文件是损坏的：[root@localhost ~]# tune2fs -l /dev/sdb

tune2fs 1.35 (28-Feb-2004)

Filesystem volume name:   Last mounted on:          Filesystem UUID:          2f3e8c46-64c0-4346-b7f6-edcfd457617a

Filesystem magic number:  0xEF53

Filesystem revision #:    1 (dynamic)

Filesystem features:      resize_inode filetype sparse_super

Default mount options:    (none)

Filesystem state:         not clean with errors

Errors behavior:          Continue

Filesystem OS type:       Linux

Inode count:              365854720

Block count:              731688960

Reserved block count:     36584448

Free blocks:              720188790

Free inodes:              365854720

First block:              0

Block size:               4096

Fragment size:            4096

Reserved GDT blocks:      849

Blocks per group:         32768

Fragments per group:      32768

Inodes per group:         16384

Inode blocks per group:   512

Filesystem created:       Fri Feb 18 14:37:14 2011

Last mount time:          Fri Feb 18 14:37:33 2011

Last write time:          Fri Feb 18 14:37:33 2011

Mount count:              1

Maximum mount count:      39

Last checked:             Fri Feb 18 14:37:14 2011

Check interval:           15552000 (6 months)

Next check after:         Wed Aug 17 14:37:14 2011

Reserved blocks uid:      0 (user root)

Reserved blocks gid:      0 (group root)

First inode:              11

Inode size:               128

Default directory hash:   tea

Directory Hash Seed:      72bc7ce8-d9db-40c4-8ee8-85e169dd4bc5

10，只有再用fsck修复下/dev/sdb，分区2T多，修复了9个小时：[root@localhost ~]# fsck.ext3 -y /dev/sdb

e2fsck 1.35 (28-Feb-2004)

/dev/sdb contains a file system with errors, check forced.

Pass 1: Checking inodes, blocks, and sizes

Journal inode is not in use, but contains data.  Clear? yes

Inode 177963137 is in use, but has dtime set.  Fix? yes

Inode 177963137 has imagic flag set.  Clear? yes

Inode 177963147 is in use, but has dtime set.  Fix? yes

Inode 177963147 has imagic flag set.  Clear? yes

Inode 177963155 is in use, but has dtime set.  Fix? yes

Inode 177963155 has imagic flag set.  Clear? yes

Inode 177963156 is in use, but has dtime set.  Fix? yes

Inode 177963156, i_blocks is 4294967295, should be 0.  Fix? yes

Inode 177963155 has compression flag set on filesystem without compression support.  Clear? yes

Inode 177963155 has INDEX_FL flag set but is not a directory.

11，修复完成后，/dev/sdb分区能够正常使用，此时发现文件系统变成ext2的了：[root@localhost ~]# df -hT

Filesystem    Type    Size  Used Avail Use% Mounted on

/dev/sda3     ext3     49G   36G   11G  78% /

/dev/sda6     ext3    812G  750G   22G  98% /bk

/dev/sda1     ext3    122M   13M  103M  12% /boot

none         tmpfs    3.9G     0  3.9G   0% /dev/shm

/dev/sda2     ext3     49G  3.2G   43G   7% /opt

/dev/sdb      ext2    2.7T  2.3T  349G  87% /test

12，用tune2fs -j把分区转成ext3：[root@localhost ~]# tune2fs -j /dev/sdb

tune2fs 1.35 (28-Feb-2004)

Creating journal inode: done

This filesystem will be automatically checked every 39 mounts or

180 days, whichever comes first.  Use tune2fs -c or -i to override.

13，成功了，分区状况也正常了，分区大部份数据还在，也能正常使用了，over：[root@localhost ~]# tune2fs -l /dev/sdb

tune2fs 1.35 (28-Feb-2004)

Filesystem volume name:   Last mounted on:          Filesystem UUID:          2f3e8c46-64c0-4346-b7f6-edcfd457617a

Filesystem magic number:  0xEF53

Filesystem revision #:    1 (dynamic)

Filesystem features:      has_journal resize_inode filetype sparse_super large_file

Default mount options:    (none)

Filesystem state:         clean

Errors behavior:          Continue

Filesystem OS type:       Linux

Inode count:              365854720

Block count:              731688960

Reserved block count:     36584448

Free blocks:              120881374

Free inodes:              360051869

First block:              0

Block size:               4096

Fragment size:            4096

Reserved GDT blocks:      849

Blocks per group:         32768

Fragments per group:      32768

Inodes per group:         16384

Inode blocks per group:   512

Filesystem created:       Fri Feb 18 14:37:14 2011

Last mount time:          Mon Mar  7 16:52:54 2011

Last write time:          Tue Mar 15 11:45:42 2011

Mount count:              4

Maximum mount count:      39

Last checked:             Fri Feb 18 22:44:35 2011

Check interval:           15552000 (6 months)

Next check after:         Wed Aug 17 22:44:35 2011

Reserved blocks uid:      0 (user root)

Reserved blocks gid:      0 (group root)

First inode:              11

Inode size:               128

Journal inode:            8404993

Default directory hash:   tea

Directory Hash Seed:      72bc7ce8-d9db-40c4-8ee8-85e169dd4bc5