OS won't boot after disk replacement

[ychaouche]

Hello,

One of the disks was amber blinking so we decided to change it. It seems (after reading some posts here and there) that the correct way of doing this is simply remove the faulty disk live, wait for 30 seconds, then plugin another disk and everything should go fine. I didn't know how to do a disk replacement, and apparently I screwed up. I hope there is some chance to get my OS back to boot. So what I did instead is grab an HP SmartStart CD, reboot the server on CD, and change the disk. The SmartStart assistant was showing RAID problems (like RAID is broken). I didn't get any screenshosts nor logs, so sorry for very vague information but basically it was saying that the 1. the disk was kaput and 2. the RAID was kaput. Then I called a colleague and out of despair we have tried many things, without even understanding what we were doing. For example, we switched all four disks to the right (they were on the left, we kept them in order though), then we moved them back to the left, then we changed the replacement disk with another replacement disk, since the error on the RAID was still there we put on the old faulty disk in the hope that the RAID would get fixed. Eventually the RAID got fixed and the logical volume, but I remember at one time when we rebooted the server we hit F2 and we agreed to lose some data (the message was saying that hitting F2 may cause some data loss), in the hope to get the RAID rebuilt, even with some data loss. So when the RAID got finally rebuilt and all 4 disks were green and there was no error or warning in the SmartStart assistant (the CD software), the server finally booted, but it is stuck at grub level (we have debian linux on it, only one OS, and only one LV in one RAID 5 array of 4 disks, without any spare).

What I am seeing right now is :

GRUB loading.

Welcome to GRUB !

error : unknown filesystem.

entering rescue mode

grub rescue > _

Any idea if this is recoverable ?

Please mention how to give you the necessary information you might need, assume I don't know how to give it to you. This is the first time I am doing this.

Thanks for any help !

[Jimmy Vance]

Before any of the forum memebers can attemtp to help. you need to provide more detail.

What model server
Which Raid Controller
Run Array Diagnostics (ADU) and attach the report

[ychaouche]

Server HP ProLiant DL380G6

Raid controller P410i

Installed OS is debian linux

I have 1 array of 4 disks into one Logical Volume.

adu-report.zip attached.

Thanks for any help !