I have a Dell PowerEdge R910 with a PERC 700 controller that has a virtual drive configured as a RAID 5 with 15 disks in it. We're running CentOS 5.10 at the moment, and I created a 15Tb ext3 filesystem on that RAID group (set this up a few years back) that has been running fine up until yesterday. I had the opportunity to add another PERC H810 controller along with a PowerVault MD1200 to add more space (44Tb as XFS), but when we went to turn the server back on, we noticed one of the disks in the RAID group had apparently failed. I didn't think much of it at the time, as it was a RAID 5, but when the server came up and I tried to mount it, I received the following 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 I tried to get a listing of backup superblocks by doing the following: [root@raos_apps01 ~]# mke2fs -b 8192 -n /dev/sdb1 Warning: blocksize 8192 not usable on most systems. mke2fs 1.39 (29-May-2006) mke2fs: 8192-byte blocks too big for system (max 4096) Proceed anyway? (y,n) y Warning: 8192-byte blocks too big for system (max 4096), forced to continue Filesystem label= OS type: Linux Block size=8192 (log=3) Fragment size=8192 (log=3) 1828894848 inodes, 1830420355 blocks 91521017 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=4311218176 27934 block groups 65528 blocks per group, 65528 fragments per group 65472 inodes per group Superblock backups stored on blocks: 65528, 196584, 327640, 458696, 589752, 1638200, 1769256, 3210872, 5307768, 8191000, 15923304, 22476104, 40955000, 47769912, 143309736, 157332728, 204775000, 429929208, 1023875000, 1101329096, 1289787624 But I am unable to actually use any of these, as they all end up giving the same error: [root@raos_apps01 ~]# e2fsck -b 65528 /dev/sdb1 e2fsck 1.39 (29-May-2006) e2fsck: Bad magic number in super-block while trying to open /dev/sdb1 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> any idea how I can get the FS back? I ordered another drive to replace the failed on thinking that *might* be part of the problem, so I will have to wait and see on that, but I SHOULD be able to mount it, but I am not able to. Thanks in advance Michael =================================== Please consider the environment before printing this e-mail Cleveland Clinic is ranked as one of the top hospitals in America by U.S.News & World Report (2015). Visit us online at http://www.clevelandclinic.org for a complete listing of our services, staff and locations. Confidentiality Note: This message is intended for use only by the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. Thank you.