Server Attachment; Scsi Interface; Maximum Bus Length Between Terminators - IBM System Storage TS3310 Setup And Operator Manual

Server Attachment

The library can be attached to servers by using:
v "SCSI Interface"
v "Fibre Channel Interface" on page 2-9

SCSI Interface

Note: Although the LVD hardware in the library is capable of operating in
The library supports SCSI LVD attachments by using SCSI cables with 68-pin,
D-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 your place of
purchase.
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:
Physical Characteristics of the SCSI Interface
The library operates as a set of SCSI-3 devices. The Ultrium Tape Drives attach to
servers using an LVD Ultra160 SCSI interface. Each SCSI drive sled uses shielded,
HD68-pin connectors, and can attach directly to a 2-byte-wide SCSI cable.
Any combination of up to two initiators (servers) and up to four targets (devices)
is allowed on a single SCSI bus if the following conditions are met:
v The SCSI bus is terminated properly at each end
v Cable restrictions are followed according to the SCSI-3 specification
Under the SCSI-3 protocol, this type of attachment allows cable lengths of up to 25
m (81 ft) with the appropriate cable and terminator. The table below gives the
maximum bus length between terminators for the LVD interface. For information
about cable connectors, see "SCSI Connectors and Adapters" on page 2-9.
2-8
TS3310 Tape Library Setup and Operator Guide
single-ended (SE) mode, SE operation is not recommended or supported.
– 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.
Note: For maximum performance, it is recommended to have a maximum of
one drive per SCSI bus.
– Only use the maximum system-to-device cable length of 25 m (82 ft) when
attaching directly to one device (a point to point interconnection).
Table 2-5. Maximum bus length between terminators
Type of Interconnection
Point-to-point (1 server and 1 drive)
Multi-drop/daisy-chain (1 server and
multiple drives)
Maximum Bus Length Between
Terminators (in meters)
25
12 (LVD)