进 fdisk /dev/sdb    用 w 命令重新保存后退出，再 fsck 即可。

# mount /dev/sdb1 /broot
mount: /dev/sdb1 is not a valid block device

# fsck -y /dev/sdb1
fsck 1.32 (09-Nov-2002)
e2fsck 1.32 (09-Nov-2002)
fsck.ext2: No such device or address while trying to open /dev/sdb1
Possibly non-existent or swap device?

# fdisk /dev/sdb

The number of cylinders for this disk is set to 8941.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
     (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

# fsck -y /dev/sdb1
fsck 1.32 (09-Nov-2002)
e2fsck 1.32 (09-Nov-2002)
/dev/sdb1: recovering journal
/dev/sdb1 has gone 192 days without being checked, check forced.

# fsck -y /dev/sdb3
fsck 1.32 (09-Nov-2002)
e2fsck 1.32 (09-Nov-2002)
/dev/sdb3: recovering journal
/dev/sdb3 has gone 192 days without being checked, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/sdb3: 90492/7520256 files (2.0% non-contiguous), 699552/15022783 blocks

# mount /dev/sdb1 /broot
# mount /dev/sdb3 /bhome