Areca Controller disk mapping is incorrect. IPP004 has 24 disk bays arranged in a 6x4 grid.

+-------+-------+-------+-------+
| disk17| disk18| disk19| disk20|
+-------+-------+-------+-------+
| disk21| disk22| disk23| disk24|
+-------+-------+-------+-------+
| disk13| disk14| disk15| disk16|
+-------+-------+-------+-------+
| disk9 | disk10| disk11| disk12|
+-------+-------+-------+-------+
| disk5 | disk6 | disk7 | disk8 |
+-------+-------+-------+-------+
| disk1 | disk2 | disk3 | disk4 |
+-------+-------+-------+-------+

• 2008-01-10T06:45:08 IDE Channel 12 Device Failed
• 2008-03-20T00:07:08 IDE Channel 12 Device Failed
• 2008-04-07T11:23:04 IDE Channel 12 Device Removed
• 2008-04-07T11:38:09 IDE Channel 12 Device Failed
• 2008-04-07T15:09:22 IDE Channel 12 Device Failed
• 2008-05-08T06:32:55 IDE Channel 6 Device Failed
• 2008-05-29T05:44:36 IDE Channel 12 Device Removed
• 2008-05-29T11:34:28 IDE Channel 12 Device Removed
• 2008-05-29T14:22:27 IDE Channel 12 Device Removed
• 2008-05-29T14:43:31 IDE Channel 12 Device Failed
• 2008-05-29T14:54:44 IDE Channel 12 Device Removed
• 2008-05-29T15:10:57 IDE Channel 12 Device Failed
• 2008-05-29T19:59:58 IDE Channel 12 Device Failed
• (disk slot 12 has been determined to be broken)
• 2008-08-20T18:20 (approx) network became unresponsive. notified by nagios. Power cycled by gavin
• 2008-08-25T20:00 (approx) system became unresponsive. Power cycled by bills
• 2008-08-30T15:00 (approx) sshd stopped responding. debug notes
• 2008-08-31T22:00 (approx) sshd stopped responding. rebooted 2008-09-01T06:30
• 2008-09-02T18:04:33 network became unresponsive (eth0: too many iterations (6) in nv_nic_irq), notified by nagios. power cycled by gavin
• 2008-09-02T19:00 (approx) ipp004 power cycled due to forcedeth failure
• 2009-06-15T17:02:53 IDE Channel 11 Reading Error
• 2010-03-08 Read Error DISK 18 replaced & array rebuilt
• 2009-08-24T07:49:39 IDE Channel 17 Device Failed attempted to swap - failed (node 21/node 17 labels exchanged)
• 2009-08-31T IDE Channel 12 Device Removed (attempt to build disk #12, bad bay, rebuild failed)
• 2009-09-1 IDE Channel 12 Device Replaced with a 1TB disk - oops. BUT REBUILDS!
• 2010-03-04 IDE Channel 18 Reading Error disc replaced
• 2010-05-20 IDE Channel 18 Reading Error (Brad attempted to replace but controller states disk #22 pulled instead of 18) Need to rebuild before pulling the disk in disk position 22, which should be 18.