I initially expanded 1 drive at a time but I got impatient and added the remaining 2 drives together. Now I deeply regret this decision.
I don't think I have 2 RDMs mapped to a single drive. I have double checked the serial numbers and also the 2 drives have different model numbers. One is an original Samsung HD204UI, the other is a Seagate RMA unit with ST2000DL004 model.
An interesting thing is that my motherboard has a very unique SATA port layout. 6 SATA 2 ports come off the Intel X58 chipset, while 4 more SATA 2 ports come off the "GIGABYTE SATA2 chip" which is a "JMB363 SATA/IDE Controller" after some digging with the PCI ID. The JMicron controller only supports 2 ports, so a JMB322 ports multiplier is connected to each channel to split it into 4 SATA 2 ports. The 2 drives are initially connected to 2 ports on the same channel. I don't know whether this is related to my problem but I have since moved all the hard drives to be connected to the Intel chipset but the problem persists.
When connecting the original 4 drives, the volume appears the same as "crashed". The files are totally unavailable in file station and the capacity shows up as "-GB/-GB". The same situation occurs when only the "not initialized" drive is attached to the DSM VM and not the "crashed" drive. When only the "crashed" drive is attached to the VM and not the other, the files become available again, same as I described in the first post.
I have tried running e2fsck -v -y -f on the volume in the DSM linux terminal according to this article but the problem persists. http://shankerbalan.net/blog/rescue-cra ... gy-volume/
Now I've installed Ubuntu on another computer and I'm currently in the process of connecting the drive to this computer and see how Ubuntu sees the drives. http://www.synology.com/en-global/support/faq/579