Compaq AA-RHGWC-TE manual Configuring a Shared Scsi Bus for Tape Drive Use

on the shared SCSI bus. Each SCSI bus must be terminated internal to the tape library at the tape drive itself with the installed SCSI terminators. Therefore, TL893 and TL896 tape libraries must be on the end of the shared SCSI bus.

In a TruCluster Server cluster with TL893 or TL896 tape libraries, the member systems and StorageWorks enclosures or RAID subsystems may be isolated from the shared SCSI bus because they use trilink connectors or Y cables. However, if there is disk storage and an ATL on the same shared SCSI bus, the ASE must be shut down to remove a tape library from the shared bus.

You can reconfigure the tape drives and robotics controller to generate other bus configurations by using the jumper cable (ATL part number 0425017) supplied in the accessories kit shipped with each TL893 or TL896 unit.

Remove the terminator from one drive and remove the internal SCSI cable from the other drive to be daisy chained. Use the jumper cable to connect the two drives and place them on the same SCSI bus.

______________________ Note _______________________

We recommend that you not place more than two drives on any one SCSI bus in these tape libraries.

Figure 8–17 shows a sample TruCluster Server cluster using a TL896 tape library in a three-bus configuration. In this configuration, tape drive 4 (Port

E)has been jumpered to tape drive 5, tape drive 2 (Port A) has been jumpered to tape drive 3, and tape drive 1 (Port B) has been jumpered to tape drive 0.

To add a TL893 or TL896 tape library to a shared SCSI bus, select the member system that will be the next to the last device on the shared SCSI bus (the tape library always has to be the last device on the shared SCSI bus). Connect a BN21K, BN21L, or BN31G cable between the Y cable on the SCSI bus controller on that member system and the appropriate tape library port. In Figure 8–17, one shared SCSI bus is connected to port

B (tape drives 0 and 1), one shared SCSI bus is connected to port A (tape drives 2 and 3), and a third shared SCSI bus is connected to port E (tape drives 4 and 5 and the MUC).

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