seagate ST150176 Installation guide

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Barracuda 50 Family:

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ST150176LW/LC

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Product Manual, Volume 1

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Barracuda 50 Family:

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ST150176LW/LC

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Product Manual, Volume 1

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© 1999 Seagate Technology, Inc. All rights reserved

Publication number: 83329471, Rev. C

June 1999

Seagate, Seagat e Technology, and the Seagate logo are registered trademar ks of Seagate Technology,
Inc. Barracuda, SeaFAX , SeaFON E, SeaBOARD, and SeaTDD are either trademarks or registered trade­marks of Seagate Technology, Inc. or one of its subsidiaries. All other trademar ks o r registered trade­marks are the property of their respective owners.

Seagate reserves the right to chang e, without notice, product offerings or specifications. No part of this

publication may be reproduced in any for m without written per mission of Seagate Technology, Inc.

Revision status summary sheet

Revision Date Writer/Engineer Sheets Affected

Rev. A

Class A Release

Rev. B 05/15/99 L. Newman/D. Rus ch

Rev. C 06/11/99 L. Newman/D. Rusch 27, 29, and 30. ECO: DJD51093.

02/24/99 L. Newman/D. Rus ch 1/1, v thru viii, 1-82

Pages 7, 8, 9, 11, 25, 49 and 53.
ECO: DJD51089

Notice.
Product Manual 83329471 is Volume 1 of a two volume document with the SCSI Interface information in

the Volume 2 SCSI Interface P roduct Manual, par t number 7773 8479.
If the SCSI Interface information is needed the Volume 2 Interface Manual should be ordered,

part number 77738479.

Barracuda 50 Product Manual, Rev. C v

Table of Contents

1.0 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

2.0 Applicable standards and reference documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.1 Standards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.1.1 Electromagnetic compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.1.2 Electromagn etic susceptibili ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.2 Electromagn etic compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.3 Reference d ocuments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3.0 General descr iption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.1 Standard features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.2 Media characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.3 Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.4 Reliabili ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.5 Unformatted and formatted capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.6 Programmable drive capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.7 Factory installed accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.8 Options (factory installed). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.9 Accessories (user installed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

4.0 Performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.1 Internal drive characteristi cs (transparent to user) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.2 SCSI performance characteristics (visible to user) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.2.1 Access tim e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.2.2 Format comm and ex ecution time (minute s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.2.3 Generalized performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.3 Start/stop time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4.4 Prefetch/multi-segmented cache control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.5 Cache operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1

4.5.1 Caching write data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.5.2 Prefetch o peration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5.0 Reliability specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.1 Error rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.1.1 Environmental interference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.1.2 Read errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.1.3 Write erro rs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.1.4 Seek errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2 Reliability and service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2.1 Mean time between failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2.2 Field failure rate vs time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2.3 Preve ntive maintenan ce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2.4 Service life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.2.5 Service philosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.2.6 Service tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.2.7 Hot plugging Barracuda 50 disc drives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.2.8 S.M.A.R.T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.2.9 Product warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6.0 Physical/electrical specific ations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6.1 AC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6.2 DC power requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6.2.1 Conduct ed noise immu nity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6.2.2 Power sequenc ing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6.2.3 Current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6.3 Power dissipation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.4 Environmental limits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

vi Barracuda 50 Product Manual, Rev. C

6.4.1 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

6.4.2 Relative humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

6.4.3 Effective altitude (sea level). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

6.4.4 Shock and vibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

6.4.5 Air cleanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

6.4.6 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

6.4.7 Electromagn etic susceptibili ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

6.5 Mechanical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

7.0 Defect and error management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

7.1 Drive inte rnal defects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

7.2 Drive erro r recovery procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

7.3 SCSI systems errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

8.0 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

8.1 Drive ID/option select header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

8.1.1 Notes for Figures 11, 12, and 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

8.1.2 Function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

8.2 Drive orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

8.3 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

8.3.1 Air flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

8.4 Drive mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

8.5 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

9.0 Interface requiremen ts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

9.1 General description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

9.2 SCSI interface messages supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

9.3 SCSI interface commands suppo rted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

9.3.1 Inquiry Vital Product data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

9.3.2 Mode Sense data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

9.4 SCSI bus conditions and miscellaneous features support ed . . . . . . . . . . . . . . . . . . . . . . . . .49

9.5 Synchronous data trans fer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

9.5.1 Synch ronous data transfer periods supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

9.5.2 REQ/ACK offset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

9.6 Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

9.6.1 DC cable and connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

9.6.2 SCSI interface physical description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

9.6.3 SCSI interface cable requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

9.6.4 Mating conn ectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

9.7 Electrical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

9.7.1 Multimode—SE or LVD alternative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

9.8 Terminator requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65

9.9 Terminator power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65

9.10 Disc drive SCSI timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66

9.11 Drive activity LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

10.0 Seagate Te chnology support serv ices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

Appendix A. Sense keys and additional sense codes supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

Barracuda 50 Product Manual, Rev. C vii

List of Figures

Figure 1. Barracuda 50 family drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2. Barracuda 50 family drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3. Typical Barracuda 50 family drive +12 V current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 4. Typical Barracuda 50 family drive +5 V current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 5. DC current and power vs. input/output operations per second (SE mode) . . . . . . . . . . . . . . 22

Figure 6. DC current and power vs. input/output operations per second (LVD mode) . . . . . . . . . . . . . 22

Figure 7. Locations of PCB components listed in Table 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 8. Recommended mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 9. Mounting configuration dimensions for “LW” model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 10. Mounting configuration dimensions for “LC” model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 11. Barracuda 50 family drive ID select for models “LW” and “LC ” . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 12. Barracuda 50 family drive ID select header J5 for “LW” model (J5 Pins 1A - 12A) . . . . . . . . 35

Figure 13. Barracuda 50 family drive J2 option select header for “LC” and “LW” models. . . . . . . . . . . . 36

Figure 14. Air flow (suggested) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Figure 15. Model “LW” drive physical interface (68 pin J1 SCSI I/O connector). . . . . . . . . . . . . . . . . . . 52

Figure 16. Model “LC” drive physical interface (80 pin J1 SCSI I/O connector) . . . . . . . . . . . . . . . . . . . 52

Figure 17. SCSI daisy chain interface cabling for “LW” model drives . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Figure 18. Nonshielded 68 pin SCSI device connector used on “LW” models . . . . . . . . . . . . . . . . . . . . 56

Figure 19. Nonshielded 80 pin SCSI “SCA-2” connector, used on “WC” and “LC” models. . . . . . . . . . . 57

Figure 20. LVD output signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Figure 21. Typical SE-LVD alternative tra nsmitter receiver circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Barracuda 50 Product Manual, Rev. C 1

1.0 Scope

This manual describes the Seagate Tec hnolo gy®, Inc. Barracuda 50™ disc dr ives.
Barracuda 50 drives support the small computer system interface (SCSI) as described in the ANSI SCSI,

SCSI-2, and SCSI-3 (Fast-20 and Fast-40) interface specifications to the extent described in this manual. The
SCSI Interface Product Manual (part number 77738479) describes general SCSI interface characteristics of
this and other families of Seagate drives.

From this point on in this product manual the reference to Barracuda 5 0 models is referred to as “the drive”
(unless references to individual models are necessary).

Figure 1.

Barracuda 50

family drive

Barracuda 50 Product Manual, Rev. C 3

2.0 Applicable standards and reference documentation

The drive has been developed as a system peripheral to the highest standards of design and construction. The
drive depends upon its hos t equipment to provide adequate power and environment in order to ach ieve opti­mum performance and compliance with applicable industry a nd governmental regulations. Special attention
must be given in the areas of safety, power distribution, shielding, audible noise control, and temperature regu­lation. In particular, the drive must be securely m ount ed in o rder to guarante e the s pecified pe rform ance c har­acteristics. Mounting by bottom holes must meet the requirements of Section 8.4.

2.1 Standards

The Barracuda 50 family complies with Seagate s tandards as not ed i n th e appropr iate s ect ions of this Ma nual
and the Seagate SCSI Interface Product Manual, part number 77738479 (Vol. 2).

The Barracuda 50 disc drive is a UL recognized component per UL1950, CSA certified to CAN/CSA C22.2 No.
950-95, and VDE certified to VDE 0805 and EN6 0950.

2.1.1 Electromagnetic compatibility

The drive, as delivered, is designed for system integration and installation into a suitable enclosure prior to use.
As such the drive is supplied as a subassembly and is not subject to Subpar t B of Part 15 of the FCC Rules
and Regulations nor the Radio Interference Regulations of the Canadian Department of Communications.

The design characteristics of the drive serve to minimize radiation when installed in an enclosure that provides
reasonable shielding. As such, the drive is capable of meeting the Class B limits of the FCC Rules and Regula­tions of the Canadian Department of Communications when properly packaged. However, it is the user’s
responsibility to assure that the drive meets the appropriate EMI requirements in their system. Shielded I/O
cables may be required if the enclosure does not provide adequate shielding. If the I/O cables are external to
the enclosure, shielded cables should be used, with the shields grounded to the enclosure and to the host con­troller.

2.1.2 Electromagnetic susceptibility

As a component assem bly, the drive is not required to me et any suscep tibility performance requi remen ts. It is
the responsibility of those integrating the dri ve within their system s to perform t hose t ests req uired and design
their system to ensure that equipment operating in the same system as the drive or external to the system
does not adversely affect the performance of the drive. See Section 5.1.1 and Table 2, DC power requirements.

2.2 Electromagnetic compliance

Seagate uses an independen t laboratory to confirm complia nce to the directives/standard(s) for CE Marking
and C-Tick Marking. The drive was tested in a representative system for typical applications. The selected sys­tem represents the most popular characteristics for test platforms. The system configurations include:

• 486, Pentium, and PowerPC microprocessors

• 3.5-inch floppy disc drive

• Keyboard

• Monitor/display

• Printer

• External modem

• Mouse

Although the test system with this Seagate m odel com plies to the directives/standard(s), we cannot guarantee
that all systems will comply. The computer manufacturer or system integrator shall confirm EMC compli ance
and provide CE Marking and C-Tick Marking for t heir product.

Electromagnetic compliance for the European Union

If this model has the CE Marking it complies with the European Union requirements of the Electrom agnetic
Compatibility Directive 89/336/EEC of 03 May 1989 as am ended by Directive 92/31/EEC of 28 A pri l 19 92 and
Directive 93/68/EEC of 22 July 1993.

4 Barracuda 50 Product Manual, Rev. C

Australian C-Ti ck

If this model has the C-Tick Marking it complies with the Au stralia/New Zealand Standard AS/NZS3548 1995
and meets the Electromagnetic Compatibility (EMC) Framework requirements of Australia’s Spectrum Man­agement Agency (SMA).

2.3 Reference documents

Barracuda 50 Installation Guide Seagate P/N 83329472
SCSI Interface Product Manual Seagate P/N 77738479

ANSI small computer system interface (SCSI) document numbers:

X3.131-1994 SCSI-2
X3T10/855D SPI
X3T10/1071D Fast-20 (also called “Ultra S CSI”)
X3T10/1142D SPI-2

X3T10/1143D
SFF-8046 Specification for 80-pin connector for SCSI disk drives
SCA-2 EIA Specification ANSI/EIA
Package Test Specification Seagate P/N 30190-001 (under 100 lb.)
Package Test Specification Seagate P/N 30191-001 (over 100 lb.)
Specification, Acoustic Test Requirements, and Procedures Seagate P/N 30553-001
In case of conflict between this document and any referenced document, this document takes precedence.

Barracuda 50 Product Manual, Rev. C 5

3.0 General description

Barracuda 50 drives combine magnetoresistive (MR) heads, partial response/maximum likelihood (PRML)
read channel electronics, embedded servo technology, and a SCSI-3 (Fast-20 and Fast-40) interface to provide
high performance, high capacity dat a storage for a variety of systems including engineering workst ations, net­work servers, mainframes, and supercomputers.

Fast-20 and F ast-40 (also known as Ultra-1 SCSI and Ultra-2 SCSI, respectively) are negotiated transfer rates.
These tran sfer rat es w ill o c c ur on ly if your ho s t adapter al so suppor t s thes e data transfer rat e s. Th is dr i ve a ls o
operates at SCSI-1 and SC SI-2 data transfer rates for backward compatibility with non-Fast-20/Fast-40 capa­ble SCSI host adapters.

Table 1 lists the features that differen tiate the various Barracuda 50 models.

Table 1: Drive model number vs. differentiating features

Model number

Number
of heads I/O circuit type [1]

Number of I/O
connector pins

Number of I/O
data bus bits

ST150176LW 22 multimode (SE/LVD) 68 16
ST150176LC 22 multimode (SE/LVD) 80 16

[1] See Section 9.6 for details and definitions.
The drive records and recovers data on 3.5-inch (86 mm) non-removeable discs.
The drive supports the S mall Computer System Interface (SCSI) as described in the ANSI SCSI-2/SCSI -3

SPI-2 interface specifications to the extent described in this manual (volume 1), which defines the product per­formance characteristics of the Barracuda 50 family of drives, and the SCSI Interface Product Manual (volume

2), part number 777384 79, which describes the general inter face characteristics of this and other families of
Seagate SCSI drives.

The drive’s interface supports multiple initiators, disconnect/reconnect, self-configuring host software, and
automatic features that relieve the host from the necessity of knowing the physical characteristics of the targets
(logical block addressing is used).

The head and disc assembly (HDA) is sealed at the factory. Air circulates within the HDA through a non­replaceable filter to maintain a contamination-free HDA environment.

Refer to Figure 2 for an exploded view of the drive. This exploded view is for information only—never disassem­ble the HDA and do not attempt to service items in the sealed enclosure (heads, media, actuator, etc.) as this
requires special facilities. The drive contains no replaceable parts. Opening the HDA voids your warranty.

Barracuda 50 drives use a dedicated landing zone at th e inner m os t radius of the media to eliminate the possi­bility of destroying or degrading data by landing i n the data zone. The d rive automatically go es to t he landing
zone when power is removed.

An automatic shipping lock prevents potential damage to the heads and discs that results from movement dur­ing shipping and handling. The sh ipping lock autom atically diseng ages when power is applied t o the drive and
the head load process begins.

Barracuda 50 dr ives deco de track 0 locat ion data f rom the servo data embedded o n eac h su rface to eliminate
mechanical transducer adjustments and related reliability concer n s.

A high-performance actuator ass embly with a low-inertia, balanced, patented, straight-arm des ign provides
excellent performance with minimal power dissipation.

6 Barracuda 50 Product Manual, Rev. C

Figure 2. Barracuda 50 famil y drive

Barracuda 50 Product Manual, Rev. C 7

3.1 Standard features

The Barracuda 50 family has the following standard features:

• Integrated SCSI controller

• Multimode SCSI single-ended or low voltage differential drivers and receivers

• 16 bit I/O data bus

• Asynchronous and synchronous data transfer protocol

• Firmware downloadable via SCSI interface

• Selectable sector sizes from 512 to 2,048 bytes/sector in multiples of 4 bytes/sector

• Programmable drive capacity

• Programmable sector reallocation scheme

• Flawed sector reallocation at format time

• Programmable auto write and read reallocation

• Reallocation of defects on command (post format)

• Enhanced ECC correction capability up to 185 bits

• Sealed head and disc assembly

• No preventative mai ntenanc e or adjustment required

• Dedicated laser textured head landing zone

• Embedded servo data rather than a separate servo data surface

• Self diagnostics performed when power is applied to the drive

• 1:1 Interleave

• Zoned bit recording (ZBR)

• Vertical, horizontal, or top down mounting

• Dynamic spindle brake

• 1 Mbyte, or optional 4 Mbyte data buffer

• Hot plug compatibility (section 9.6.4.2 lists proper host connector needed) for “LC” model drives

• SCAM (SCSI Configured AutoMagically) plug-n-play level 2 compliant, factory set to level 1 (not user select-

able)

• Low audible noise for office environment

• Low power consumption

3.2 Media characteristics

The media used on the drive has a diameter of approximately 3.5 inches (86 mm). The aluminum substrate is
coated with a thin film magnet ic materi al, overcoated with a proprie tary prot ective layer for improved dura bility
and environmental protection.

3.3 Performance

• Supports in dustr y standard Fast-20 and Fast-40 SCSI interfaces (also called “Ultra-1 SCSI” and “Ultra-2
SCSI,” respectively)

• Programmable multi-segmentable cache buffer (see Section 4.4)

• 7200 RPM spindle. Average latency = 4.17 ms

• Command queuing of up to 64 commands

• Background processing of queue

• Supports start and stop commands (spindle stops spinning)

3.4 Reliability

• 1,000,000 hour MTBF

• LSI circuitry

• Balanced low mass rotary voice coil actuator

• Incorporates industr y-standa rd Self-Monitori ng, Analysis and Reporting Technol ogy (S.M.A.R.T.)

• Incorporates Seek To Improve Reliability algorithm (STIR)

• 5-year warranty

8 Barracuda 50 Product Manual, Rev. C

3.5 Unformatted a n d formatted capacities

Formatted capacity depends on the number of spare reallocation sectors reserved and the number of bytes per
sector. The following table shows the standard OEM model capacities data.

Formatted data block size
512 bytes/sector [1] Unformatted

ST150176 05D2B03Bh (50 GB) [2] 63.1 GB

Notes.

[1] Sector size selectable at format time. Users having the necessary equi pment may modify the data block

size before issuing a format command and obtain di fferent fo rmatted capacities than those listed. See
Mode Select Command and Format Command in the SCSI Interface Product Manual, part number

77738479.

[2] User available capacity depends on s pare reallocation scheme selected. The number of data tracks per

sparing zone and the num ber of alternate s ectors (LBAs) per spar ing zone can be de termined by using
the Mode Sense command and reading Mode Page 03h. Total LBAs(h) x 200(h) = total byte capacity.

3.6 Programmable drive capacity

Using the Mode Select command, the drive can change its capacity to something less than maximum. See the
Mode Select Parameter List table in the SCSI Inte rface Product Manual, part number 77738479. Refer to the
Parameter list block descriptor number of blocks field. A value of zero in the nu mber of blocks fi eld indicates
that the drive shall not change the capacity it is currently formatted to have. A number in the number of blocks
field that is less than the max imum number o f LBAs changes the total drive capacity to the value i n the block
descriptor number of blocks field. A value greater than the maximum numb er of LBAs is rounded down t o the
maximum capacity.

3.7 Factory installed accessories

OEM Standard drives are shipped with the Barracuda 50 Installation Guide, part number 83329472 (unless
otherwise specified). The factory also ships with the drive a small bag of jumper plug s used for the J2, J5, and
J6 option select jumper headers.

3.8 Options (factory installed)

All customer requested options are in corporated duri ng production or packaged at t he manufacturing facility
before shipping. Some of the options available are (not an exhaustive list of possible options):

• Other capacities can be ordered depending on sparing scheme and secto r size requested.

• 4 Mbyte buffer size.

• Single unit shipping pack. T he drive is nor mally shipped in bulk packaging to provide max imum protection

against transit damage. Units shipped individually require additional protection as provided by the single unit
shipping pack. Users planning single unit distribution should specify this option.

• One B arracuda 50 Installation Guide, part numbe r 83 329472, is included with each standard OEM drive
shipped, but extra copies may be ordered.

3.9 Accessories (user installed)

The following accessories are available. All accessories may be installed in the field.

• Single unit shipping pack.

Barracuda 50 Product Manual, Rev. C 9

4.0 Performance characteristics

4.1 Internal drive characteristics (transparent to user)

ST150176

Drive capacity 50.07 GByte (formatted, rounded off values)
Read/write heads 22
Bytes/track 189.28 kbytes (average, rounded off values)
Bytes/surface 2,276 Mbytes (unformatted, rounded off values)
Tracks/surface (total) 12,024 Tracks (user accessible)
Tracks/inch 12,905 TPI
Peak bits/inch 252 K BPI
Internal data rate 153 - 264 Mbits/sec (variable with zone)
Disc rotational speed 7,184 r/min
Average rotational latency 4.17 msec
Recording code 8/9 EPR4

4.2 SCSI performance characteristics (visible to user)*

The values given in Section 4.2.1 apply to all models of the Barracuda 50 family unless otherwise specified.
Refer to Section 9.10 and to the S CSI Interface Product Manual, par t number 77738 479, for additional timing
details.

4.2.1 Access time [8]

Including cont roller overhead
(without disconnect) [1] [4]

Driv e l e ve l

Read Write

msec
Average – Typical [3] 7.6 8.4
Single Track – Typical [3] 0.9 1.2
Full Stroke – Typical [3] 16 17

4.2.2 Format command execution time (minutes) [1]*

ST150176

Maximum (with verify) 120
Maximum (no verify) 70

4.2.3 Generalized performance chara cteris tics

Minimum sector interleave 1 to 1

Data buffer transfer rate to/from disc media (one 512-byte sector):

Min. [4]*
Avg. [4]
Max. [4]

19.1

27.8

33.0

MByte/sec
MByte/sec
MByte/sec

Data buffer transfer rate to /from disc media: (< 1 track):

Min. [4]
Avg. [4]
Max. [4]

MByte/sec divided by (interleave factor)

14.9
MByte/sec divided by (interleave factor)

21.7
MByte/sec divided by (interleave factor)

25.7

*[ ] All notes for Section 4.2 are listed at end of Section 4.2.3.

10 Barracuda 50 Product Manual, Rev. C

SCSI interface data transfer rate (asynchronous) [5]:

Maximum instantaneous 6.0 Mbytes/sec [6]

Maximum average 6.0 Mbytes/sec [7]
Synchronous transfer rate for SCSI Fast-20 (Ultra-1 SCSI): 40 Mbytes/sec
Synchronous transfer rate for SCSI Fast-40 (Ultra-2 SCSI): 80 Mbytes/sec
Synchronous transfer rate for fast SCSI-2: 20 Mbytes/sec
Sector Sizes:

Default 512 byte user data blocks

Variable 512 to 2,048 bytes per sector in multiples of 4

bytes per sect or.
If n (number of bytes per sector requested) is

odd, then n-1 sectors will be used.

Read/write consecutive sectors on a track Yes
Flaw reallocation performance impact (for flaws reallocated at format time using

Negligible

the spare sectors per sparing region reallocation scheme.)
Overhead time for head switch (512 byte sectors) in sequential mode 1.2 msec

Overhead time for one track cylinder switch in sequential mode 1.2 msec (typical)
Average rotational latency 4.17 msec (calculate)

Notes for Section 4.2.

[1] Execution time measured from receipt of the la st Byte of the Command Descriptor Block (CDB) to the

request for a Status Byte Transf er to the Initiator (excluding connect/disconnect).

[2] Maximum times are specified over the worst case conditions of temperature, voltage margins and drive

orientation. When comparing spec ified access times, care should be taken to distinguish between typical
access times and maximum access times. The best comparison is obtained by system benchmark tests
conducted under identical conditions. Maximum times do not include error recovery.

[3] Typical Access times are measured under nominal conditions of temperature, voltage, and horizontal ori-

entation as measured on a representative sample of drives.
[4] Assumes no errors and no sector has been relocated.
[5] Rate measured from the start of the first sector transfer to or from the Host.
[6] Assumes system ability to support the rates listed and no cable loss.
[7] Simulated.
[8] Access time = controller overhead + average seek time

Access to data = controller overhead + average seek time + latency time

4.3 S tar t/stop ti me

After DC power at nominal voltage has been applied, the drive becomes ready within 30 seconds if the Motor
Start Option is disabled (i.e. the motor starts as soon as the power has been applied). If a recoverable error
condition is detected during the star t sequence, the drive executes a recovery procedu re which may cause the
time to become ready to exceed 30 sec onds. During spin up to read y time the drive responds to some c om­mands over the SCSI interface in less than 1.5 seconds after appl ication of power. Stop time is less than 20
seconds from removal of DC power.

If the Motor Start Option is enabled, the inter nal controller accept s the commands listed in the SCSI Interface
Product Manual less than 3 seconds after DC power has been applied. After the Motor Start Command has
been received the drive becomes ready for normal operations within 25 seconds typically (excluding an error
recovery procedure). The Motor Start Command can also be used to command the drive to stop the spindle
(see SCSI Interface Product Manual, part number 77738479).

There is no power control switch on the drive.

Barracuda 50 Product Manual, Rev. C 11

4.4 Prefetch/multi-segmented cache control

The drive provides prefetch (read look-ahead) and multi-segmented cache control algorithms that in many
cases can enhance system performance. “Cache” as used herein refers to the drive b uffer storage space when
it is used in “cache” operations. To s elect prefetch and cache features the host sends the Mode Select com­mand with the proper values in the a pplicable bytes in Mode Page 08h (see SCSI Interface Product Manual,
part number 77738479. Prefetch and cache operation are independent features from the standpoint that each
is enabled and disabled independently via the Mode Select command. However, in actual operation the
prefetch feature overlaps cache operation som ewhat as is noted in Section 4.5.1 and 4.5.2.

All default cache and prefetch Mode parameter values (Mode Page 08h) for standard OEM versions of this
drive family are given in Table 9.

4.5 Cache operation

In general, all but 840 Kbytes (3,600 k bytes of th e 4, 096 kbytes on unit s with t his op tion) of the physical buffer
space in the drive can be used as s torage space for cache operations. The buffer can be divided into logical
segments (Mode Sele ct Page 08h, byte 13) from which data is read and to which data is written. The drive
maintains a table of logical block disk medium addresses of the da ta stored in each se gment of the buffer. If
cache operation is enabled (RCD bit = 0 in Mode Page 08h, byte 2, bit 0. See SCSI Interface Product Manual,
part number 77738479), data requested by t he host with a Read com mand is retr ieved from the buffer (if it is
there), before any disc access is initiated. If cache operation is not enabled, the buffer (still segmented with
required number of segments) is still used, but only as circular buffer segments during disc medium read oper­ations (disregarding Prefetch operation for the moment). That is, the drive does not check in the buffer seg­ments for the requested read data, but goes directly to the medium to retrieve i t. The retrieved data m erely
passes through some buffer segment on the way to the host. On a cache “miss”, all data transfers to the host
are in accordance with “buffer-full” ratio rules. On a cache “hit” the drive ignores the “buffer-full” ratio rules. See
explanations associated with Mode page 02h (disconnect/reconnect control) in the SCSI Interface Product
Manual.

The following is a simplified description of a read operation with cache operation enabled:

Case A -

A Read command is received and the first logical block (LB) is already in cache:

1. Drive transfers to the initiator the first LB requested plus all subsequent contiguous LB’s that are already in
the cache. This data may be in multiple segments.

2. When a requested LB is reached that is not in any cache segment, the drive fetches it and any remaining
requested LBs from the disc and puts them in a segment of the cache. The drive transfers the remaining
requested LBs from t he cac he to the host in acco rdance with the disconnect/reconnec t sp ecification men­tioned above.

3. If the prefetch feature is enabled, refer to Section 4.5.2 for operation from this point.

Case B -

A Read command requests data, the first LB of which is not in any segment of the cache:

1. The drive fetches the requested LB’s from the disc and transfers them into a segment, and from there t o
the host in accordance with the disconnect/reconnect specification referred to in case A.

2. If the prefetch feature is enabled, refer to Section 4.5.2 for operation from this point.

Each buffer segment is actually a self-contained circular storage (wrap-around occurs), the length of whic h is
an integer number of disc medium sectors. The wrap-around capability of the individual segments greatly
enhances the buffer’s overall performance as a cache storage, allowing a wide range of user selectable config-
urations, which includes their use in the prefetch operation (if enabled), even when cache operation is disabled
(see Section 4.5.2). The number of segm ents may be selected using the Mode Select comm and, but the size
can not be directly selected. Size is selected only as a by-product of selecting the segment number specifica­tion. The size in Kbytes of each segment is not reported by the Mode Sense command page 08h, bytes 14 and

15. The value 0XFFFF is always reported. If a size specification is sent by the host in a Mode Select command

(bytes 14 and 15) no new segment size is set up by the drive, and if the “STRICT” bit in Mode pag e 00h (byte
2, bit 1) is set to one, the drive responds as it does for any attempt to change unchangeable parameters (see
SCSI Interface Product Manual, part number 777384 79). The drive supports operation of any integer number
of segments from 1 to 16.

12 Barracuda 50 Product Manual, Rev. C

4.5.1 Caching write data

Write caching is a write operation by the drive that makes use of a drive buffer storage area where the data to
be written to the medium is stored in one or more segments while the drive performs the write command.

If read caching is enabled (RCD=0), t hen dat a written to the medium is retained in the cache to be made avai l­able for future read cache hi ts. The sam e buffer space and segmentation is us ed as set up for read f unct ions.
The buffer segmentation scheme is set up or changed indep endently, having nothing to do with the state of
RCD . When a write command is issued, if RCD= 0, the cache is first checked to see if any logical blocks that are
to be written are already stored in the cache from a previous read or write command. If there are, the respec­tive cache segments are cleared. The new data is cached for subs equen t Read com man ds.

If the number of write data logi cal blocks exceeds the size of the segment bei ng written into, when the end of
the segment is reached, the data is written into the beginning of the same cache segment, overwriting the data
that was written there at the beginning of the operation. However, the drive does not overwrite data that has not
yet been written to the medium.

If write caching is enabled (WCE=1), then t he drive may return GOOD status on a wri te command after the
data has been transferred into the cache, but before the data has been written to the medium. If an error occurs
while writing the dat a to the medium, and G OOD status has already been returned, a deferred error will be
generated.

The Synchronize Cache command may be used to force the drive to write all cached write data to the medium.
Upon completion of a Synchronize Cache command, all data received from previous write commands will have
been written to the medium . The Start/Stop com mand with the stop bit set will force a sync cache operation
before the drive stops.

Table 9 shows Mode default settings for the drives.

4.5.2 Prefetch operation

If the Prefetch feature is enabled, data in con tig uous l ogical blocks on the disc immediately beyond that wh ich
was requested by a Read command can be retrieved and stored in the buffer for immediate transfer from the
buffer to the host on subsequent Read commands that request those logical blocks (this is true even if “cache”
operation is disabled). Though the prefetch operation uses the buffer as a “cache”, finding the requested data
in the buffer is a prefe tch “hit”, not a “cache” operation “hit”. Prefetch is enabled using Mode Select page 08h,
byte 12, bit 5 (Disable Read Ahead - DRA bit). DRA bit = 0 enables prefetch. Since data that is prefetched
replaces data already in some buffer segment(s), the host can limit the amount of prefetch data to optimize
system performance. The max prefetch field (bytes 8 and 9) limits the amount of prefetch. The drive does not
use the prefetch “ceiling” field (bytes 10 and 11).

During a prefetch operation, the drive crosses a cylinder boundar y t o fetch more data only if the Discontinuity
(DISC) bit is set to one in bit 4 of byte 2 of Mode parameters page 08h.

Whenever prefetc h (read look-ahead) is enabled (enabled by DRA = 0), it operates under the control of ARLA
(Adaptive Read Look-Ahead). If the host uses software interleave, ARLA enables prefetch of contiguous blocks
from the disc when it senses that a prefetch “hit” will likely occur, even if two consecutive read operations were
not for phy sically contiguous blocks of data (e.g. “software interleave”). ARLA disables prefetch when it decides
that a prefetch “hit ” will not likely o ccur. If the ho st is no t us ing s oftware inter leave, and if two seque ntial read
operations are not for contiguous blocks of data, ARLA disables prefetch, but as long as sequential read oper­ations request contiguous blocks of data, ARLA keeps prefetch enabled.

Barracuda 50 Product Manual, Rev. C 13

5.0 Reliability specifications

The following reliability specifications assume correct host/drive operational interface, including all interface
timings, power supply voltages, environmental requirements and drive mounting constraints (see Section 8.4).

Seek Errors

Less than 10 in 10

Read Error Rates [1]

Recovered Data Less than 10 errors in 10
Unrecovered Data Less than 1 sector in 10

Miscorrected Data Less than 1 secto r in 10
MTBF 1,000,000 hours
Service Life 5 years
Preventive Maintenance None required

Note.

[1] Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.

5.1 Error rates

The error rates stated in this specification assume the following:

• The drive is operated per this specification using DC power as defined in this manual (see Section 6.2).

• The drive has been formatted with the SCSI FORMAT commands.

• Errors caused by media defects or host system failures are excluded from error rate computations. Refer to

Section 3.2, “Media Characteristics.”

8

seeks

12

bits transferred (OEM default se ttings)

15

bits transferred (OEM default settings)

21

bits transferred

5.1.1 Environmental interference

When evaluating syste ms operation under conditions of Electromagnetic Interference (EMI), the performance
of the drive within the system shall be c onsidered acc eptable if the drive does not generate an unrecoverable
condition.

An unrecoverable error, or unrecoverable condition, is defined as one that:

• Is not detected and corrected by the drive itself;

• Is not capable of being detected from the error or fault status provided through the drive or SCSI interface; or

• Is not capable of being recovered by normal drive or system recovery procedures without operator interven-

tion.

5.1.2 Read errors

Before determination or measurement of read error rates:

• The data that is to be used for measurement of read error rates must be v erifi ed as being written correctly on
the m edia.

• All media defect induced errors must be excluded from error rate calculations.

5.1.3 Write errors

Write errors can occur a s a result of media defects, environmental interference, or equipment malfunction.
Therefore, write errors are not predictable as a function of the number of bits passed.

If an unrecoverable write error occurs because of an equipment malfunction in the drive, t he error is classified
as a failure affecting MTBF. Unrecoverable write errors are those which cannot be corrected within two
attempts at writing the record with a read verify after each attempt (excluding media defects).

14 Barracuda 50 Product Manual, Rev. C

5.1.4 Seek errors

A seek error is defined as a failure of the dr ive to posi tion the heads to the addressed track. There shal l be no
more than ten recoverable seek errors in 10

8

physical seek operations. After detecting an initial seek error, the
drive automatically performs an error recovery process. If the error recovery process fails, a seek positioning
error (15h) is reported with a Medium error (3h) or Hardware error (4h) reported in the Sense Key. This is an
unrecoverable seek error. Unrecoverable seek errors are classified as failures for MTBF calculations. Refer t o
the SCSI Interface Product Manual, par t number 77 738479, for Request Sense in formation. S ee also Appen­dix A of this manual for a list of sense keys and additional sense codes supported by this drive.

5.2 Reliability and service

You can enhance the reliability of Barracuda 50 disc drives by ensuring that the drive receives adequate cool­ing. Section 6.0 provides temperatu re measurem ents and other i nformation that m ay be used to enha nce the
service life of the drive. Section 8.3.1 provid es recomm ended air-flow information.

5.2.1 Mean time between failure

The production disc dri ve shall achieve an MTBF of 1,000,000 hours w hen operated in an environment that
ensures the case temperatures specified in Section 6.4.1, Tabl e 3, Column 2 are not exceeded. Short-term
excursions up to the specification limits of the operating environment will not affect MTBF performance. Contin­ual or sustained operation at case temperatures above the values shown in Table 3, Column 2 m ay degrade
product reliability.

The following expression defines MTBF

Estimated power-on operating hours in the period

MTBF per measurement period =

Number of drive failures in the period

Estimated power-on operation hours means power-up hours per disc drive times the total number of disc drives
in service. Each disc drive shall have accumulated at least nine months of operation. Data shall be calculated
on a rolling average base for a minimum period of six months.

Drive failure means any s toppage or substandard performance caused by drive malfunction.

5.2.2 Field failure rate vs time

The expected field failure rate is listed below. Drive utilization will vary. An estimated range of utilization is:

• 720 power-on hours (POH) per month.

• 250 on/off cycles per year.

• Read/seek/write operation 20% of power-on hours.

• Systems will provide adequate cooling to ensure the case tempe ratures specified in Section 6.4.1 are not

exceeded.

Month 1 2,364 PPM
Month 2 1,422 PPM
Month 3 1,403 PPM
Month 4 1,391 PPM
Month 5 1,317 PPM
Month 6 1,255 PPM
Month 7 1,162 PPM
Month 8+ 1,025 PPM

Failure rate is calculated as follows:

• No system-induced failures are counted

• Based on 1,000,000 MTBF and 720 power-on hours per month

• Month 1’s rate includes a 300 PPM installation failure

5.2.3 Preventive maintenance

No routine scheduled preventiv e maintenance shall be required.

Barracuda 50 Product Manual, Rev. C 15

5.2.4 Service life

The drive shall have a usef ul service life of five years. Depo t repair or replacement of major parts is permitt ed
during the lifetime (see Section 5.2.5).

5.2.5 Servi c e philosophy

Special equipment is required to repair the drive HDA. In order to achieve the above service life, repairs must
be performed only at a proper ly equipped and st affed service and r epair facility. Troubleshooting and repair of
PCBs in the field is not rec ommended, because of the extensive diagnostic equi pment required for effective
servicing. Also, there are no spare parts available for this drive. Drive warranty is vo ided if the HDA is opened.

5.2.6 Service tools

No special tools are required for site installation or recommended for site maintenance. Refer to Section 5.2.5.
The depot repair philosophy of the drive precludes the necessity for special tools. Field repair of the drive is not
practical since there are no user purchasable parts in the drive.

5.2.7 Hot plugging Barrac uda 50 disc drives

The ANSI SPI-2 (T10/1142D) docum ent defines the physical requirements for removal and insertion of SCSI
devices on the SCSI bus. Four cases are addressed. The cases are differentiated by the state of the SCSI bus
when the removal or insertion occurs.

Case 1 A ll bus devices powered off during removal or insertion
Case 2 RS T signa l asserted continuously during removal or insertion
Case 3 Current I/O processe s not allowed during inser tion or removal
Case 4 Current I/O proces s allowed during insertion or removal, exc ept on the device being changed

Seagate Barracuda disc drives support four hot plugging cases. Provision shall be made by the system such
that a device being inserted makes power and ground connections prior to the connection of any device signal
contact to the bus. A device being removed shall maintain power and ground connections after the disc onnec­tion of any device signal contact from the bus (see SFF-8046, SCA-2 specification).

It is the responsibility of the systems integrator to assure that no hazards from temperature, energy, voltage, or
ESD potential are presented during the hot connect/disconnect operation.

All I/O processes for the SCSI device being insert ed or removed shall be quiescent. All SCS I devices on the
bus shall have receivers that conform to the SPI-2 standard.

If the device being hot plugged uses single-ended (SE) drivers and the bus is currently operating in low voltage
differential (LVD) mode, then all I/O processes for all devices on the bus must be completed, and the bus qui­esced, before attempting to hot plug. Following the insertion of the newly installed device, the SCSI host
adapter must issue a Bus Re set, followed by a synchronous transfer negotiation. Failure to perform the SCSI
Bus Reset could result in erroneous bus operations.

The SCSI bus termination and termination power source shall be external to the device being inserted or
removed.

End users should not mix devices with high voltage differential (HVD) drivers and receivers and devices with
SE, LVD, or multimode drivers and receivers on the same SCSI bus since the common mode voltages in the
HVD environment may not be controlled to safe levels for SE and LVD devices (see ANSI SPI-2).

The disc drive spindle must come to a complete stop prior to completely rem oving the drive from the cabinet
chassis. Use of the Stop Spindle command or partial withdrawal of the drive, enough to be disconnected from
the power source, prior to removal are methods for insuring that this requirement is met. During drive insertion,
care should be taken to avoid exceeding the limits stated in Section 6.4.4, "Sh ock and vibration," of this man­ual.

16 Barracuda 50 Product Manual, Rev. C

5.2.8 S.M.A.R.T.

S.M.A.R.T. is an acronym for Self-Monitoring Anal ysis and Re porting Techn ology. This tec hnology is intended
to recognize conditions that indicate a drive failure and is designed to provide sufficient warning of a failure to
allow data back-up before a n actual failure occurs.

Note.

The firmware will monitor specific attributes for degradation over time but cannot predict instantaneous
drive failures.

Each attribute has been selecte d to m onitor a s pecific s et of failure conditions in th e operating pe rformanc e of
the drive, and the thresholds are optimized to minimize “false” and “failed” predictions.

Controllin g S.M.A.R.T.

The operating mode of S.M.A.R.T. is controlled by the DEX CPT bit and the PERF bit of the “Informational
Exceptions Control Mode Page” (1Ch). The DEXCPT bit is used to enable or di sable the S.M.A.R.T. process.
Setting the DEXCPT bit will disable all S.M.A.R.T. functions. When enabled, S.M.A.R.T. will collect on-line data
as the drive performs normal read/write operations. When the PERF bit is set, the drive is considered to be in
“On-line Mode Only” and will not perform off-line functions.

The process of meas uring off-line attributes and saving data can be forced by the RTZ (retur n to zero) com­mand. Forcing S.M.A.R.T. will r es et the timer so that the next schedule d interrupt will be two hours.

The drive can be interrogated by the host to determine the time remaining before the next scheduled measure­ment and data logging process will occur. This is accomplished by a log sense command to log page 0x3E.
The purpose is to allow the customer to control when S.M.A.R.T. interruptions occur. As described above, f orc­ing S.M.A.R.T by the RTZ command will reset the timer.

Performance impact

S.M.A.R.T. attribute data will be saved to the disc for the purpose of recreating the events that caused a predic­tive failure. The drive will measure and s ave parameters once every two hours subject t o an idle period on the
SCSI bus. The process of measuring off-line attribute data and saving data to the disc is uninterruptable and
the maximum delay is summarized below:

Maximum processing delay

On-li ne o nly de l ay Fully enabled de lay
DEXCPT = 0, PERF = 1 DEXCPT = 0, PERF = 0

S.M.A.R.T. delay times 50 milliseconds 50 milliseconds

Repor tin g c on t rol

Reporting is c ontrolle d i n the “Informational Exceptions Control Page” (1Ch). Subject to the reporting method,
the firmware will issue to the “host” an 01-5D00 sense code. The error code is preserved through bus resets
and power cycles.

Determining rate

S.M.A.R.T. monitors the rate at wh ich errors occur and sig nals a predictive failure if the rate of degraded error
rate increases to an unacceptable level. To determine rate, error events are logged and compared to the num ­ber of total operations for a gi ven attribute. The interval defines the number of operations over which to mea­sure the rate. The counter that keeps track of the current number of operations is referred to as the Interval
Counter.

S.M.A.R.T. measures error rate, hence for each attribute the occurrence of an “error” is recorded . A counter
keeps track of t he num ber of errors for the current interval. This counter is referred to as the Fai lure Counter.

Error rate is simply the number of errors per operation. The algorithm that S.M.A.R.T. uses to record rates of
error is to set thresholds for t he number of errors and the i nterval. If the number of errors exceeds the threshold
before the interval expires, then the error rate is considered to be unacceptable. If the number of errors does
not exceed the threshold before the interval expires, then the error rate is considered to be acceptable. In either
case, the interval and failure counters are reset and the process star ts over.

Barracuda 50 Product Manual, Rev. C 17

Predictive failures

S.M.A.R.T. signals predictive failures when the drive is p erform ing unacc eptably for a per iod of t ime. T he firm ­ware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accom­plish this, a counter is incremented whenever the error rate is unacceptable and decremented (not to exceed
zero) whenever the error rate is acceptable. Should the counter continually be incremented such that it reaches
the predictive threshold, a predictive failure is signaled. This counter is referred to as the Failure History
Counter. There is a separate Failure History Counter for each attribute.

5.2.9 Product warranty

Beginning on the date of shipment to customer and continuing for a period of five years, Seagate warrants that
each product (including components and subassemblies) or spare part that fails to function properly under nor­mal use due to defect in materials on workmanship or due to nonconformance to the applicable specifications
will be repaired or replaced, at Seagate ’s option and at no charge to customer, if returned by customer at cus­tomer’s expense to Seagate’s designated facility in accordance with Seagate’s Warranty Procedure. Seagate
will pay for tran sporting the repair or replaceme nt item to customer. For more detailed warranty information
refer to the Standard terms and condition s of Purchase for Seagate products.

Shipping

When transpor ting or shipping a drive, a Seagate approved containe r must be used. Keep your original box.
They are easily identified by the Seagate Appr oved Package labe l. Shipping a drive in a non-approved con­tainer voids the drive warranty .

Seagate repair centers may refuse recei pt of compon ent s im properly packaged or obviously damage d in tran­sit. Contact your Authorized Seagate Distributor to purchase additional boxes. Seagate recommends s hipping
by an air-ride carrier experienced in handling computer equipment.

Product repair and re turn information

Seagate customer service centers are the only facilities authorized to service Seagate drives. Seagate does
not sanction any third-party repair facilities. Any unauthorized repair or tampering with the factory-seal voids
the warranty.

Barracuda 50 Product Manual, Rev. C 19

6.0 Physical/electrical specifications

This section provides information rela tin g to the physical and electrical characteristics of the Barracuda 50
drive.

6.1 AC power requirem ents

None.

6.2 DC power requirements

The voltage and current requirements for a single drive are shown in the following table. Values indicated apply
at the drive power connector. The table shows current values in Am peres. See also Fig ure 3c for current and
power values vs. number of I/O operations.

T able 2: DC power requirements

ST150176

Notes

Voltage +5 V +12 V +5 V +12 V
Regulation [5] ±5% ±5%[2] ±5% ±5%[2]
Average idle current DCX

[1] 0.66 0.71 0.67 0.71

Maximum starting current

(peak DC) DC
(peak AC) AC

[3]

[3]
Delayed motor start (max) DC [1][4] 0.59 0.02 0.60 0.02
Peak operating current

Typical DCX
Maximum DC

[1][6]

[1]

Maximum (Peak)

SE Mode LVD Mode

0.75

1.34

0.74

0.77

1.07

2.6

3.4

1.15

1.22

2.6

0.78

1.4

0.78

0.81

1.26

2.6

3.4

1.15

1.22

2.6

[1] Measured with average reading DC ammeter. Instantaneous +12 V current peaks will exceed these val-

ues. Power supply is at nominal voltages.

[2] For +12 V, a –10% droop is permissible during initial start of spindle, and must return to ±5% before 7,200

rpm is reach ed. The ±5% must be maintained a fter the drive signifies that its power-up sequence has

been completed and that the drive is able to accept selection by the host initiator.
[3] See +12 V current profile in Figure 3.
[4] This condition occurs when the Motor Star t Option is enabled and the drive has not yet received a Start

Motor co mm a n d.
[5] See Section 6.2.1 “Co nducted Noise Immunity.” Specified voltage tolerance is inclusive of ripple, noise,

and transient response.
[6] Operating condition is defined as random 8 block reads at 142 input/o utput operations per second. Cur-

rent and power specified at nominal voltages. Decreasing +5 V supply by +5% increas es 5 V current by

0.3%. Decreasing +12 V supply by 5% increases +12 V current by 3.2%.

General Notes from Tabl e 2:

1. Minimum current loadin g for each supply voltage is not less than 0.7% of the maxim um operating current

shown.

2. The +5 and +12 volt supplies shall employ separate ground returns.

3. Where power is provided to multiple drives from a common supply, careful consideration for individual drive

power requirements should be noted. Where multiple units are powered on simultaneously, the peak star t ­ing current must be available to each device.

4. Parameters, other than spindle start, are measure d after a 10-minute warm up.

5. No terminator power.