Greg, Dave:

following the failure of the E18-0 Pod-1 Disk-6 last week, Nexsan sent a replacement 6TB HDD today. Greg and I hot swapped the disks at 13:00 and added the new disk to the raid at 14:50. It is in the process of being rebuilt, which for a 6TB drive in background mode could take some time.

This was a truly hot swap, with the h1fw0 frame writer running throughout with no problems.