Quantum Essential Settings for Optimizing SCSI Controller Performance with LTO Technology

Chapter 6 UNIX Settings

A Word About SCSI Controllers

A Word About SCSI Controllers

The LTO-3 Tape Drive transfers data natively at 68 Mbytes per second. It supports the SCSI Ultra 160 specification and can transfer data at burst rates of up to 320 Mbytes per second. To achieve maximum drive performance, it is important to choose high-performance disk drives for your system, as well as high-performance SCSI controllers.

Configuring for the DEC/Compaq UNIX Environment

Finding Existing

SCSI Controllers

and Devices

Configuring Digital UNIX Version 4.0 and later/Compaq Tru64 Unix 5.x

SCSI ID #7 is almost always dedicated to the SCSI controller. Never configure your target device for ID 7 unless you are absolutely sure that the controller is not addressed for ID 7.

Use File Manager to open the file /etc/ddr.dbase and create an entry as follows:

SCSIDEVICE

#

Type=tape Name="CERTANCE""ULTRIUM 3"

#

PARAMETERS:

TypeSubClass=tk

TagQueueDepth=0 MaxTransferSize=0x0ffffff#(16MB-1) ReadyTimeSeconds=180#seconds

CMD_PreventAllow=supported

CMD_ExtReserveRelease=supported BlockSize=0 PwrMgmt_capable=0

DENSITY:

#

DensityNumber=0,2,3,4,5,6,7

DensityCode=default

CompressionCode=0x0

Buffered=0x1

54 LTO-3 Tape Drive User’s Guide