Chapter 4. Configuring the Library

SCSI Initiator

Set the SCSI Initiator mode from the second configuration screen; to get there from the main screen, press Config > More.

Unless specifically recommended by the backup software vendor, leave the SCSI Initiator on. When the SCSI Initiator is on, the library communicates with the drives via the SCSI bus. The library queries the drives before and after tape loads and unloads, and it returns the status of the drive to the host. When SCSI Initiator is off, the host system is responsible for determining the status of the drives.

Touch the + and - symbols to toggle the SCSI Initiator on and off.

Touch Save Parms > No, because it is not necessary to restart the library for these changes to take effect.

SCSI Bus Mode

Set the bus mode (most often left at the default of 0) from the second configuration screen; to get there from the main screen, press Config > More. This setting determines the maximum data transfer rate.

The following table indicates the maximum SCSI bus transfer rate for specified SCSI Bus Mode settings. The SCSI Bus Mode setting of 0 is the default.

SCSI Bus Mode

AIT-2 Setting

AIT-3 Setting

 

 

 

0

40 MB/sec

80 MB/sec

 

 

 

1

20 MB/sec

40 MB/sec

 

 

 

2

16.1 MB/sec

32.2 MB/sec

 

 

 

3

13.2 MB/sec

26.4 MB/sec

 

 

 

4

11.4 MB/sec

22.8 MB/sec

 

 

 

5

10 MB/sec

20 MB/sec

 

 

 

Note: Some HBAs do not function properly with Ultra SCSI transfer rates (40 MB/sec, AIT-2 libraries only). Libraries with AIT-2 tape drives are shipped from the factory with the SCSI Bus Mode set to 0.

If your system experiences problems with the higher transfer rate, you can experiment setting it to SCSI Bus Mode 1 to force fast wide transfers.

To change the SCSI bus mode, set the configuration option in the third Configuration screen. Be sure to save the parameters and restart the library.

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Spectra Logic 10000 manual Scsi Initiator, Scsi Bus Mode