I added two 3TB WD drives to the PRO-6 (there were 4 1.5 tb Seagates in slots 1-4). The first drive expansion worked normally. The second expanded horizontally, then I did the reboot to do the vertical expansion step. The resync hung at 100% for no appararent reason. Rebooting attempts did not work, eventually I held in the power button to force a restart.
Upon the restart, the PRO started a new resync on drive 6. The log said "Data volume will be rebuilt with disk 6." What was particularly odd is that per Frontview, drives 5 and 6 were dead. After the resync completed, drive 6 had 1.5 TB (of the 3) allocated, and the PRO said volume C was unprotected and 9 TB.
Looking at the SMART stats for 1-4, I saw a rapid rise in reallocated sectors on drive 2 (up to around 75 at the moment). So I am thinking that drive 2 failed during the expansion, and provoked the original hang (but I see no way to tell).
I then shut down the system through frontview, pulled the plug, and reseated all 6 drives. Upon power up, the volume is still unprotected, Drive 6 is still marked as dead, but drive 5 is shown as normal. Thought all this was really strange, so I shut it down again. Tomorrow I'll run drive diagnostics on a PC.
Is there any way to sort out exactly what went wrong? I am thinking that I will need to replace drive 2, and since the volume is unprotected, I will need to start over, and restore it from backups. Rather annoying, since I had drive redundancy when I started the expansion... But since Drive 6 had 1.5 TB allocated on the final re-sync, is it possible that the system rebuilt drive 6 to replace drive 2?
The numbers don't add up. The total allocated space is 9750 GB, since the volume is unprotected I should have a volume of around that size. There's no explanation on why the PRO only allocated 1392 GB on drive 6. Seems to me that the PRO somehow created a very strange raid configuration.
Any thoughts on what to do next? (other than replace drive 2 of course).
