The HP MSA is a fairly popular storage device with a good feature set for small to medium sized organizations. It makes use of the familiar HP Array Configuration Utility for configuration but its front panel leaves something to be desired. I was able to obtain a document from HP support the details exactly what all of those blinking indicators really mean.
| Indicator | Function | Description |
| 0 – 2 | Busy status | ON = Indicates this array controller is idle OFF = Indicates this array controller is operating at full capacity |
| 3 – 7 | Fibre Channel ID | Indicates the 5 bit ALPA assigned to this array controller (not applicable when in fabric mode.) |
| 8 | Idle Heartbeat | Indicates the Array controller is idle and functioning |
| 9 | Active/Standby | ON = Controller is active OFF = Controller is in standby |
| 10 | DMA active | ON = DMA transfers are active |
| 11 | Logical I/O active | ON = Currently processing logical requests from the Host Adapter |
| 12 | SCSI Bus 0 active | ON = Indicates requests are outstanding on the first SCSI bus |
| 13 | SCSI Bus 1 active | ON = Indicates requests are outstanding on the second SCSI bus |
| 14 | Cache Activity | ON = Cache active OFF = No cache activity BLINK = Cache transfer pending |
| 15 | Drive failure | ON = A configured hard drive has failed in the array |
| 16 | Redundancy Active | ON = indicates two controllers are in a redundant mode of operation OFF = The indicator will not be lit if there is only one array controller inserted or if the array controllers are not redundant due to some type of failure. Redundant cables must be connected to enable redundancy. |
| 17 | Fault | Amber indicates an error message has been sent to the controller display |