Dell PowerVault TL4000 - Manual (Page 49)

Logical Unit Number (LUN) Scanning
The library uses a single SCSI or Loop ID per drive and dual LUNs to control the
tape drive (LUN 0) and library accessor (LUN 1). The library requires a Host Bus
Adapter (HBA) that supports LUN scanning. If it is not enabled, your host system
will not scan beyond LUN 0 and will fail to discover the library. It will only see
the tape drive.
Important: Some HBAs, such as RAID controllers, do not support LUN scanning.
Host Interfaces
The 2U library and the 4U library can be attached to servers using the following
interfaces:
v SCSI (LVD Ultrium 160)
v Serial Attached SCSI (SAS)
v Fibre Channel
Table 3-1. Host Drive Interface Support
Drive SCSI (LVD Ultra 160) SAS FC
Ultrium 3 FH X X
Ultrium 3 HH X*
Ultrium 3 HH v2 X*
Ultrium 4 FH X* X
Ultrium 4 HH X* X
Ultrium 4 HH v2 X* X
Ultrium 5 HH X* X
Ultrium 6 HH X* X
Note: * = Dual Port SAS
SCSI Interface
Note: Although the LVD hardware in the library is capable of operating in
single-ended (SE) mode, SE operation is not recommended.
The library supports SCSI LVD attachments by using SCSI cables with 68-pin,
HD-connectors. SCSI adapters must be properly terminated.
Before installing the SCSI cables, inspect all cables for damage. Do not install a
cable if it is damaged. Report the damage immediately by contacting Dell customer
care.
The maximum allowable length of your bus cabling depends on the type of SCSI
bus that you use (LVD).
v For a server with an LVD SCSI bus:
– Use a maximum system-to-device cable length of 10 m (33 ft) when attaching
to the host interface board (SCSI) and one or two daisy-chained drives.
– Use a maximum system-to-device cable length of 5 m (17 ft) when attaching
to the host interface board (SCSI) and three to six daisy-chained drives.
Chapter 3. Installation Planning 3-7