Data recovery help needed...

[COSU]

Hi ALL, my CentOS server failing. It has 4 hard drive raid. It is not even letting me go to the bios. When booting up it goes to the total blank screen or with blinking cursor. I can't do anything although I tried with multiple different function key. I am not sure what went wrong. So I am now really need to recover the data. I was used as the webserver. I have another server that can only hold two hard drive so I installed same version CentOS on the primary hard drive of that second server and slaving hard drives on by one from the failing server. I don't know which one has the data.

I can't mount the drive. Here is where i am now. What best route i can do to recovery the data (especially the SQL) from the old drive so I can use it to rebuild the website.

[root@root ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 1.5G 0 loop /tmp
sda 8:0 0 74.5G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 74G 0 part
├─VolGroup-lv_root (dm-0) 253:0 0 35.3G 0 lvm /
├─VolGroup-lv_swap (dm-1) 253:1 0 5G 0 lvm [SWAP]
└─VolGroup-lv_home (dm-2) 253:2 0 33.8G 0 lvm /home
sdb 8:16 0 232.9G 0 disk
├─sdb1 8:17 0 350M 0 part
├─sdb2 8:18 0 97.7G 0 part
├─sdb3 8:19 0 73.2G 0 part
└─sdb4 8:20 0 1K 0 part
sr0 11:0 1 1024M 0 rom


I am now at the Step#5 of that guide page. When I try mounting, I get this:
[root@root ~]# mount /dev/sdb1 /mnt/chroot/
mount: you must specify the filesystem type

So I check the file system and got this:
[root@root ~]# fsck -N /dev/sdb1
fsck from util-linux-ng 2.17.2
[/sbin/fsck.ext2 (1) -- /dev/sdb1] fsck.ext2 /dev/sdb1

Then I use the filesystem and got this:
[root@root ~]# mount -t ext2 /dev/sdb1 /mnt/chroot/
mount: wrong fs type, bad option, bad superblock on /dev/sdb1,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so

[root@root ~]# dmesg | tail
[ 1663.864955] VFS: Can't find an ext2 filesystem on dev sdb1.

I tried with ext3 and ext4 also but no luck.

[aks]

Default on C7 is xfs.