IBM 4690 manual Overview, Tape Capacity, Low cost, High Speed Data Transfer

Chapter 1. Overview

The operating system provides support for the following tape drives:

vEIDE Internal

vSCSI Internal

vSCSI External

Refer to the IBM 4690 OS V2: User's Guide for more information on using the

Streaming Tape Drive Utility.

The following table shows the tape drives supported.

Name	Manufacturer	Model Number	Part Number
IBM 4.0/8.0GB TR4 Internal	Options by IBM	2359	06H9720
EIDE Tape Drive
Seagate ATAPI TapeStor	Seagate Technologies,	TST8000R-ABET
8000	Inc.
IBM TR-4 4.0/8.0 GB	Options by IBM		06H9716
Internal SCSI Tape Drive
IBM TR-4 4.0/8.0 GB	Options by IBM	3502-900
External SCSI Tape Drive
TapeStor 8000 TR-4 4-8 GB	Seagate Technologies,	TST8000R-SBET
Internal SCSI Tape Drive	Inc.
TapeStore 8000 TR-4 4-8 GB	Seagate Technologies,	TST8000E-SBET
External SCSI Tape Drive	Inc.

Tape Capacity

A Travan TR-4 cartridge can store up to 4 GB of uncompressed data. However, the actual capacity per cartridge varies according to the number and size of the ®les to be stored. Because the Travan TR-4 cartridge is designed to store data from an entire hard disk, under normal conditions you should not need to insert a second tape. The large storage capacity allows the tape drive to be used in unattended mode (Remote Command Processor), which is a signi®cant advantage over tape drives that have smaller capacities and require user intervention to change tapes.

Low cost

Because only one cartridge is needed for most system backups, you save on tape cartridge cost. One Travan TR-4 cartridge may be cheaper than multiple smaller capacity tapes.

High Speed Data Transfer

The tape drive is capable of transferring raw data at 600 KB per second. Part of this data, Error Correction Code (ECC) data, is used to recover from read errors. The resulting throughput should be about 30 MB per minute when the tape drive is able to maintain streaming.

Buffered Data to Maintain Streaming

The tape drive's RAM allows buffering of data in the hardware. The software in the Store Controller also has a buffer. With buffering in the hardware and the software, the number of underruns should be reduced.

© Copyright IBM Corp. 1998 1