lost partition table
Have an old Dell 1850 with a PowerVault 220S storage array attached to it. The array is configured with 2 logical disks, both hardware raid-5 - /dev/sdb and /dev/sdc. OS was Gentoo.
Over the weekend I decided to replace Gentoo, so powered everything down, detached the PowerVault from the server, took out the original boot drive and popped in a new one. From there I installed Enterprise Linux and plugged the PowerVault back in. The 2 logical disks are there an visible, but their partition tables are gone!
Ugh.
I ran gpart, but nothing was found except "possible swap" which is just plain wrong. Since this box was set up years ago and I have no good notes I am just guessing they each had just one big partition of type Linux RAID Autodetect. I was using mdadm to concatenate the drives. I decided to go ahead an create the partitions I thought were there, but mdadm still gives me no joy.
Popping my original boot disk in doesn't change anything - mdadm can't rebuild the array.
I'm completely baffled. No clue how the partiotn tables disappeared. (I'm fairly certain I was not using raw devices in the array, but did try mdadm sans the partiton tables and had no luck.)
The PowerVault wasn't even attached to the server or powered on during all the OS work, so tis whole thing makes no sense. Must be hardware failure of some kind?
Anyway, if anyone has any ideas for how I might get mdadm to recognize the devices and repair md0 I'd love to hear them. I know the data must still be on the disks.
[root@ogre etc]# fdisk -l
Disk /dev/sda: 73.4 GB, 73407868928 bytes
255 heads, 63 sectors/track, 8924 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 8663 69585516 83 Linux
/dev/sda2 8664 8924 2096482+ 82 Linux swap / Solaris
Disk /dev/sdb: 2199.0 GB, 2199014866944 bytes
255 heads, 63 sectors/track, 267348 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
Disk /dev/sdc: 1400.7 GB, 1400704598016 bytes
255 heads, 63 sectors/track, 170292 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
[root@ogre etc]# lsmod |grep raid0
[root@ogre etc]# modprobe raid0
[root@ogre etc]# modprobe dm-mod
[root@ogre etc]# mdadm --assemble --scan
mdadm: No devices listed in conf file were found.
[root@ogre etc]# cat /proc/mdstat
Personalities : [raid0]
unused devices: