How do I make my dell 2850 recognize its raid volume?

Question

OK I'm not very familiar with raid so I apologize in advance if I don't explain this properly.

I have a Dell PE2850 I've been using for a few years as a web server. Recently it complained that one of the drives in the system raid 1 array was failing (though hadn't failed yet). Not wanting to risk the second drive failing I took two brand new 146GB U320 drives over to the data centre to replace the aging 36GB U320 drives.

The configuration at this point was two 36GB drives in slot 0 and slot 1, these two drives were raid 1. In slot 2 there was an extra 36GB drive that wasn't in use (wasn't initialized or part of a volume).

I went into the Dell server admin application and off-lined the spare drive and off-lined the failing drive in slot 1. I then put the 146GB drives into slots 2 and 3 (1 is empty now). I ran the create volume wizard and put the two 146s into a raid 1 volume. At this point everything is ok.

I got the Norton Ghost disc out (I was planning to mirror the OS to the new volume) and rebooted the server. At this point it says that none of the drives are responding check connectors, cables and power. I did and all the drives were green.

I asked my friend and he said it probably didn't like the fact there was nothing in slot 1, so I moved a 146GB from slot 3 to slot 1 and it now says there are no logical volumes.

When I go into the volume configuration menu it shows all the drives are ready.

How do I get it to recognize the original system volume drive in raid 1 so that I get my data back?

I appreciate any advice so I can avoid this problem in the future.

Answer 1

first of all, you need to get the system back online

1. insert both old drives in the slots they were in, go into the raid utility (Ctrl+A or Ctrl+E on POST, can't remember which one)
2. the utility might recognise these old drives and bring the array back up itself. If it doesn't, you need to remove the disks, clear the controller config, insert the disks back in, and create a new raid array, VERY IMPORTANT - do not allow the controller bios to initialise the array - this will destroy all the data you have.

at this stage you should have the old config back up and running.

next you remove the faulty disk, replace it with a new disk, and assign the new disk as hotspare. this will have the array rebuilding onto the new disk (using up 36Gb out of 146) after the rebuild is complete, replace the second 36Gb disk, and rebuild again.

this should place you in a setup where you have two large drives in raid-1, using up 36Gb on both.

What you can do now is create a new logical disk (raid array) on the rest of the drives, and either mirror it or use separately. this will give you the extra space as a separate partition

Answer 2

It said that there is no logical volume because you created the volume using the other slots. I'm willing to bet that particular PERC keeps drive information entirely on the controller, and in a per slot configuration.

I'd recommend either getting a third disk and using it as a hot spare or removing it entirely and putting in an empty carrier. After recreating the array, of course.

Answer 3

If your controller is reporting that all the disks are ready, then your RAID controller has no RAID configuration. In the RAID configuration screen (Ctrl+M) during RAID init, Slots 0 and 1 should say something like

ID
 0  ONLIN A00-00
 1  ONLIN A00-01

Maybe something got foobar'ed somewhere but if there is no RAID configuration you'll need to import the configuration back. But since they're not displaying "Foreign" then this may not be possible.

• If you haven't reseated the disks I'd try that first. (while off of course)
• Place disk 1 back in. So you have disks 0-3 inserted.
• Power on and see if you can import the disks from the RAID controller.

Otherwise, if your 2850 is still in warranty (mine are just expiring) I would really recommend calling Dell.