Recovering Foreign/Unconfigured(bad) drives
Q: My RAID controller reports a foreign configuration was detected during boot, and all of my drive bays have red lights on them. I try to import the configuration, but it fails. How do I import the configuration?
A: Failure to import arrays usually means that the drives were unexpectedly powered off or disconnected from the RAID controller, which puts them in the Unconfigured(bad) state. This is done as a precautionary measure to prevent drives with bad connections from joining the array, as sudden disconnects can result in data corruption.
These scenarios may also be accompanied by errors regarding preserved cache on the controller, where if there were pending write operations at the time of the failure the controller withholds the data until the disks are verified working, again as a preventative measure against data corruption.
Drives stuck in the Unconfigured(bad) state need to be manually set back to Unconfigured(good) before they will be importable. Please be aware that this procedure does not guarantee that your data will be restored, and has the potential to further damage your data if the drives are failing due to hardware defects.
If you accept the risks and wish to import the configuration anyway, you can set drives to Unconfigured(good) through the MegaRAID BIOS, then retry to import configuration.
1. During controller initialization in POST, hit <CTRL+H> to enter the MegaRAID BIOS. Select your controller from the prompt, and hit Start.
2. Navigate to the Drives menu option in the left pane, or hit <ALT+D> and <Enter>.
3. On the next page, select an unconfigured drive, click on the Properties radio button, and then click on Go.
4. On the next page, select Make Unconf Good, then click on Go. Repeat steps 3 and 4 for every Unconfigured(bad) drive.
5. Once all the drives have been marked good, head back to the MegaRAID BIOS home page, then click on Scan Devices to initiate a rescan of the enclosures. This should then prompt you with any foreign configurations detected, which you can then import.