Get data from unbootable Linux server hard disk
===

Here is my situation.

The CentOS 5 server in my work place, after a sudden shutdown due to power out, now cannot boot.

My co-worker and me need to get importance file from its hard drive before re-install the OS.

However, when we connect its hard drive to another Linux PC, and try to mount it, we get error.

The below is the info after type 
    fdisk -1

    Disk /dev/sda: 500.1 GB, 500107862016 bytes
    255 heads, 63 sectors/track, 60801 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/sda1   *           1          13      104391   83  Linux
    /dev/sda2              14       60801   488279610   8e  Linux LVM
    
    Disk /dev/sdb: 500.1 GB, 500107862016 bytes
    255 heads, 63 sectors/track, 60801 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    
       Device Boot      Start         End      Blocks   Id  System
    /dev/sdb1   *           1       25496   204796588+  83  Linux
    /dev/sdb2           25497       60801   283587412+  8e  Linux LVM

The one I want to get file is /dev/sdb1 and /dev/sdb2.

However, when I type 

    mount /dev/sdb1 /haccan

I get this error:

    mount: wrong fs type, bad option, bad superblock on /dev/sdb1,
           missing codepage or other error
           In some cases useful info is found in syslog - try
           dmesg | tail  or so

Do we have to do something before we are be able to access to the file in the hard disk?