关于debian下的分区问题

txl829

debian:~# fsck /dev/sda3
fsck 1.37 (21-Mar-2005)
e2fsck 1.37 (21-Mar-2005)
Couldn't find ext2 superblock, trying backup blocks...
fsck.ext2: Bad magic number in super-block while trying to open /dev/sda3
请问fsck具体有什么用，出这样的结果是不是说我的分区是损坏的，或者不是ext2的文件系统？
我用 mount -t ext2 /dev/sda3 /usr会出这样的结果
mount: wrong fs type, bad option, bad superblock on /dev/sda3,
       missing codepage or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so


debian:/# fdisk -l

Disk /dev/sda: 36.7 GB, 36747104256 bytes
64 heads, 32 sectors/track, 35044 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes


4 partitions:
#       start       end      size     fstype   [fsize bsize   cpg]
  a:        2       502       501       ext2                     
  b:      503      2903      2401       swap                     
  c:     2904      7672      4769       ext2                     
  d:     7673     35044     27372       ext2                     
debian:/#

搞了很久了，请高手帮忙啊

txl829

用fcsk还有一点信息
The superblock could not be read or does not describe a correct ext2
filesystem.  If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>