Dell TL2000 manual Logical Unit Number LUN Scanning, Host Interfaces, Scsi Interface

exception in case of a “removed” condition. A drive slot which does not contain a drive and has a position between used slots needs to be reported as a SCSI element. To signal the host application that this slot is not usable, its ACCESS bit will be disabled.

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:

vSCSI (LVD Ultrium 160)

vSerial Attached SCSI (SAS)

vFibre 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 4	FH		X*	X
Ultrium 4	HH		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).

vFor 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.

3-6Dell PowerVault TL2000 Tape Library and TL4000 Tape Library User's Guide