LEDs on the IOMs

In a duplex array, all DE120S, DE240S and DE600S drive shelves have two I/O modules (IOMs).

  • Each IOM has an Attention LED and a Locate LED.

  • Each IOM has four SAS ports, each with a Port Link LED and a Port Attention LED.

The following illustration shows the IOM LEDs.
Figure 1. IOM LEDs

LED Status Description
1 SAS Port Attention Amber

One or more of the links in the port are not working properly.


The port is optimal and no link error has occurred.

2 SAS Port Link Green

The SAS port established a link (with either a controller or another drive shelf).


No link is established to another SAS port.

3 IOM Attention Amber

The IOM is not functioning correctly.


The IOM is functioning correctly.

4 Locate Blue
There is an active request to physically locate the drive shelf.
Note: When this LED is activated, the Locate LED on the left end cap of the drive shelf is also activated. Locate LEDs turn off automatically after 30 minutes.

There is no active request to locate the drive shelf.