We have a Dell PowerEdge T620. The system reports a foreign configuration found. Upon loading the foreign configuration the following physical hard drive report is found in the BIOS:
Physical Disk 1 - Offline
Physical Disk 2 - missing
It seems to be a RAID 5 configuration. There are a total of 6 physical disks. It looks like it's possible to force the offline disk (disk 1) online, but I have read that could corrupt the entire thing.
Any way to determine whether forcing disk 1 online will solve the issue and allow rebuild of the virtual drive?
Foreign configurations should have two options available, clear and import. If the virtual disk is functional/online then you should not attempt an import. An import operation will attempt to bring disks back online. A clear operation will delete the virtual disk tags from the disk. When the tags are deleted the disk should go to a ready state. Foreign configuration operations are controller wide, when you choose clear or import it will perform that action on all foreign disks on the controller. You can read more in the controller manual.
If you have drives that are going into non-optimal states or producing any type of errors you should run diagnostics and review all available logs to troubleshoot for potential issues. Updates typically resolve issues, so you should also keep your system updated with the latest BIOS, firmware, and drivers.