IBM BladeCenter S SAS RAID Controller Module Installation And User Manual page 110

SAS RAID Module Activity LED (Green)
100
IBM SAS RAID Controller Module: Installation and User's Guide IBM BladeCenter S SAS RAID Controller Module
The SAS RAID Module Activity LED is used by the SAS RAID Module to
indicate that the status of system activity on the storage system.
Valid States: OFF, SOLID, FLASHING
OFF – Indicates main DC power is not present
SOLID – The is no SAS RAID Module storage system activity.
FLASHING – The flash rate of the Activity LED indicates SAS
RAID Module a rate proportional to the level of SAS interface
(host and/or device) activity as determined by the SAS Bridge
Device.