I'm sorry, I was avoiding this thread until I had time to answer ALL of the related posts. My apologies to you.
I suppose I would have considered killing it after 5 to 6 hours, definitely if it was still running after 10 hours. I don't have any ideas yet as to what could have gone wrong. Can you tell if there is any I/O to the drive? Syslog may help, post your diagnostics (Need help? Read me first!) We should take this to a separate thread.
Thank you, that's all I needed to know. The only indication that there is something going on is the number of writes listed on the Main tab is slowly increasing for that drive and the parity drive. The syslog only shows that the process has started and nothing related since. Because this is in preparation for some significant hardware changes (new motherboard etc.), I am not really that worried about it. I've got 2 other 500GB drives I was planning on removing from the array as well and so as soon as I get my new drive precleared and the data moved off those other 2 drives, I'll just rebuild parity anyways.