A single cable in a SAS setup can actually carry multiple SAS connections (I know the SAS5E adapter (3Gbit/s, but also SAS) can do 4 SAS connections for a combined bandwidth of 12Gbit/s to an MD3000). It's very possible that a tape library doesn't support multiple SAS connections and therefor only uses a single SAS connection in that cable, leave the rest of them unused. Maybe someone that's more familiar with SAS tape libraries can confirm this (my knowledge is based on SAN arrays).
we have a R810 with a Dell SAS 6Gbps HBA connected to a ML6010, the LEDs on the controller are amber. according to the manual, amber LEDs mean "One or more links in the port is not connected. This is only applicable in a wide port configuration."however, i find nowhere if thats something i should worry about, or if connecting LTO-5 SAS drives are using wide port configuration. Anyone happens to know more about this? Thanks Florian
SAS 6Gbps HBA LEDs