Sas Configuration Requirements; Table 3.2 Supported Sas Speeds - Fujitsu Storage ETERNUS LT140 User Manual

Chapter 3 Connections
3.1 Host Connection
3.1.3

SAS Configuration Requirements

Serial Attached SCSI (SAS) is a computer bus technology mainly used to transfer data to and from storage
devices, including disk drives and tape drives. SAS is designed to transfer data at up to 6 Gbit/s.
SAS uses serial connections, with a direct connection between the host server and each of the storage devices.
This eliminates the need to configure SCSI busses and assign SCSI IDs, as is required for parallel SCSI devices.
The host server must have a SAS host bus adapter with an external connector. The HBA uses multiple LUNs to
communicate with the library. Verify that your HBA supports multiple LUNs, as most RAID controllers do not.
Most SAS HBA ports have four SAS channels. A tape drive uses one channel, so each HBA port can support up
to four tape drives. You can use a cable with one connector on each end, but only one channel will be used.
Supported speeds by drive generation are shown in the table below.
Table 3.2 Supported SAS speeds
LTO generation
LTO-6
LTO-7
LTO-8
• High quality SAS cables rated at the transfer rate the SAS drives are required. Always verify that the SAS
cable you are using is rated for the data transfer speed of the interface of your components. SAS cables
described as "equalized" may not support 6 Gbit/s data rates and should not be used with LTO-6 or later
generation tape drives unless these cables are verified for 6 Gbit/s data rates.
• The library has one or more mini-SAS connectors on each SAS tape drive. Mini-SAS connectors are keyed.
Do not force a SAS cable's mini-SAS connector into the tape drive as it might be keyed differently.
A SAS tape drive is identified by a unique identifier called a World Wide Name (WWN) or World Wide Identifier
(WWID). The library assigns the WWID to the drive bay. When a tape drive is replaced, the WWID is re-
assigned to the new tape drive.
The operating system tracks the WWID for the tape drive on each HBA channel. Each of the drive connectors
on the fan-out cable is associated with an HBA channel. Once a tape drive has been plugged in, it should
remain on the same channel to retain the association between the HBA channel and WWID.
FUJITSU Storage ETERNUS LT140 Tape Library User's Guide -Site Planning-
Supported speeds
1.5 Gbit/s, 3 Gbit/s, 6 Gbit/s
1.5 Gbit/s, 3 Gbit/s, 6 Gbit/s
1.5 Gbit/s, 3 Gbit/s, 6 Gbit/s
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