The system boots now currently right?
If so; either use Openmanage Server Administrator to clear forgeign or go into the CTRL R for the RAID as the system is coming up.
CTRL R will probably be the easiest.
Hit that as the system is coming up.
Once in there; on the first page; highlight the controller (It'll be the top option in the tree)
Hit F2. You have an option to Clear Foreign.
Say yes.
That'll take care of that problem.
At that point I'd recommend setting this problem drive as a hotspare and see if it will rebuild. If it does; you're good to go (Update RAID firmware after the rebuild is finished)
If it doesn't you're problly looking at a bad disk.
Good luck!
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by: gardmanITPosted on 2009-05-21 at 03:21:36ID: 24439698
Just to avoid confusion / errors.
I am assuming here that the RAID 1 pair have your OS installed and the RAID5 set (4 disks) is used for data and is not involved in booting the server. I also infer from the question that the "foreign" disk is one of the 4 RAID5 disks.
This would be the correct way to have the server set up as you do not want raid 5 involved in the boot process as if the RAID card loses its memory raid 5 disks can't be "recovered" to boot from whereas eith of your Raid1 mirroered pair should be bootable without any Raid data from the card.
Problem.
For some reason your raid card seems to think one of the disks in the raid 5 set is a "foreign" disk, this means the disk has probably failed and is not returning the serial number it did before. As a result the raid card see's the disk as foreign (it thinks its a disk its never seen before and this was un-expected to it),
Best Solutiion.
There should be no need to destroy the Raid5 set at all. Raid 5 is redundant so you can afford to lose 1 disk in a raid 5 set without losing the data or access to it (the machine will access this drive more slowly when a disk is failed). You need to carefully identify the disk shown as "foreign" in the raid card config, get the config utility to flash the lights on the disk, SAS disks on the Poweredge 2950 are hot swappable so go ahead now and pull this disk out of the unit.
Your raid card will now see something it can handle, a failed disk in a Raid 5 set. You will get some amber lights and warnings that the raid 5 set is degraded but your server should now boot.
Now to resolve the "foreign disk" This disk may be faulty - hence why it was seen as foreign, or it may have had a glitch. If now its booted you shove it back in the raid controller will either, see the original disk or see a new disk and rebuild the "missing" data on it from the other 3, or see it as faulty and ignore it.
Sorry I can't remember if the RAID card on the 2950 does this automatically, I dont think it does so you can use Dell Server Administrator in windows to check the status of the disk once re-instralled and start the rebuild process.
If the disk shows as faulty order a replacement PDQ as you have no redundancy left on the raid 5 set until the disk is replaced and it will be slow performance from the set till its replaced and the rebuild is complete.
Good Luck,
Ian.