User1962,   The foreign flag is when the Virtual Disk data stored on the drives doesn't match the Virtual Disk configuration data on the controller. If you follow this link, on page 73 and 74 are descriptions and steps on resolving the foreign. 
Hello, We have a PowerEdge R630 server with 2 SATA disks on the PERC controller configured as RAID1. We updated the OS (windows server 2012 R2) of our server yesterday and rebooted the server. After rebooting, the second disk (drive 1) became faulty and the system doesn't boot (we tried also removing and reinserting that disk : same issue). We tried to boot this time with only the first disk plugged (drive 0). the system doesn't boot. On the iDRAC, it shows the state of that disk : foreign (although no operations were done on this disk). So the new situation is : 1 disk not faulty and shown as foreign and the other disk is faulty (and has been now removed). Can we fix the disk (drive 0) so we can recover the data inside?
PowerEdge R630 : 2 disks error