Restore RAID 0 and Recover data
 

I'm running SME Server 7.2 based on CentOS 4.5 on Compaq Deskpro machine P3 733Mhz RAM 512mb.

With system everything is ok. Its on seperate PCI Adaptec SCSI Adapter as RAID 1. Hard drives /dev/sda and /dev/sdb.

I've got a problem with RAID 0 /dev/md0 consists of two hard drives with partitions /dev/hda1 and /dev/hdb1 connected to system IDE as master and slave.

/etc/raidtab

raiddev /dev/md0
raid-level linear
nr-raid-disks 2
persistent-superblock 1
chunk-size 64
device /dev/hda1
raid-disk 0
device /dev/hdb1
raid-disk 1

It was monted as /.../storage

/etc/fstab

/dev/main/root / ext3 usrquota,grpquota 1 1
/dev/md1 /boot ext3 defaults 1 2
none /dev/pts devpts gid=5,mode=620 0 0
none /dev/shm tmpfs defaults 0 0
none /proc proc defaults 0 0
none /sys sysfs defaults 0 0
/dev/main/swap swap swap defaults 0 0
/dev/md0 /home/e-smith/files/ibays/storage ext3 nodev,nosuid 0 2
/dev/hdc /media/cdrom auto pamconsole,exec,noauto,managed 0 0
/dev/fd0 /media/floppy auto pamconsole,exec,noauto,managed 0 0

After some reboot it stopped at boot screen with error

Setting up logical Volume Management: [OK]
Starting up RAID devices: md0
No RAID disks
Setting up logical Volume Management: [OK]
Checking filesystems
/dev/md1: clean, 40/26104 files, 16689/104320 blocks
/dev/md0: Note: if there is several inode or block bitmap blocks
which require relocation, or one part of the inode table
which must be moved, you may wish to try running e2fsck
with the `-b 32768` option first. The problem may lie only
with the primary block group descriptor, and the backup
block group descriptor may be OK.

/dev/md0: Block bitmap for group 1 is not in group. (block 0)

/dev/md0: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
(i.e., without -a or -p options) [FAILED]

OK, I took /dev/md0 out of /etc/fstab and its working fine just without /.../storage

When I run fdisk -l it shows diferent hard disk geometry for /dev/hda and /dev/hdb. (???)

Disk /dev/hda: 251.0 GB, 251000193024 bytes
2 heads, 4 sectors/track, 61279344 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Device Boot Start End Blocks Id System
/dev/hda1 1 61279344 245117374 fd Linux raid autodetect

Disk /dev/hdb: 251.0 GB, 251000193024 bytes
255 heads, 63 sectors/track, 30515 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/hdb1 1 30515 245111706 fd Linux raid autodetect

Disk /dev/md0: 502.0 GB, 502000254976 bytes
2 heads, 4 sectors/track, 122558656 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Device Boot Start End Blocks Id System
/dev/md0p1 1 61279344 245117374 fd Linux raid autodetect

Is it possible somehow to restore /dev/md0 and recover data?

Thanks in advance.

From what I know about raid, is if the raid was broken somehow, all of the data is lost for good.


But keep looking you might be able to find something out, I don't know much about raid or how it works (or else i would be using it on my desktop lol )

Thanks Sequalit for your answer.
Some time ago I already fixed this problem in some very simple way. I just booted up machine with Knoppix Live CD and it showed me pretty nice hda1 partition on my desktop. So, I'm just transfered files to another machine via FTP and job is done.
Just few directories and some files were corrupted, but its not big deal for recovering about 400GB.
Thanks. All the best.