So, fist at all, if you have a degraded RAID5, at least one drive has an error and is out of sync. If automatic rebuid is enabled, the controller should try to rebuild in the background. But rebuild can only work, if all drives are healthy or if you have a spare disk, which can be used.
The first time, your system starts in degraded mode, maybe rebuil dwas started in the background (the disc access is slow in that condition).
If you have changed something in the setup, you may have destroyed your Raid configuration. If not, everything should look as expected, the controller should show all existing drives and the status. It may be, that you have reset the degraded state using one of your utilities, nevertheless the Raid has an error. This may produce the error as the boot sequence is not able to load a file from the position, where it is expected. But it can also point to the situation, that the Raid configuration is destroyed or files are damaged during your operations.
If a RAID fails, at least one of the drives have a problem. If you try to rebuild a RAID onto a damaged drive, the result depends a little bit, how the controller can handle this. It should happen, that the controller falls back into degraded mode.
If your data is important, you should make drive images from each drive to avoid loosing data, which may recoverable. Also I would test all drives (all manufacturers have DOS tools for that) to find out, if any of the drives are really damaged. Make sure, alle drives are within the same slot as they where before testing them.
If you can find a damaged drive, you can try to replace the drive and to start a new rebuild. Also the server should start without the damaged drive in degraded mode.
If more than one drive has errors, you may have a lager problem. If no drive shows an error (also using the long drive tests, which will take 1 or 2 hours to run), check all cables for the drives.
Independend from the way of recovery, make sure that all drives are healthy, otherwise you will run into this situation again.
If the Raid is fully operational (no error and rebuild) and you still get a read error during boot, I would say that this is a sign for data corruption. You can try to copy the files again into the system using the repair console, but you never can be sure, if something esle is damaged ord not.
by: dkumar82Posted on 2008-12-30 at 08:00:01ID: 23263442
Better contact DELL support, if it is a Critical Server.