seagate ST336704LW, ST336704LWV, ST336704LC, ST336704LCV Product Manual

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Cheetah 36LP Family:

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ST336704LW/LWV/LC/LCV

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Product Manual, Volume 1

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Cheetah 36LP Family:

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ST336704LW/L WV/LC/LCV

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Product Manual, Volume 1

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© 2000-2001 Seagate Technology LLC All rights reserved

Publication number: 83329476, Rev. E

January 2001

Seagate, Seagate Techn ology, and the Seagate logo are re gistered trademarks of Seagate Technology
LLC. Cheetah, SeaFAX, SeaFONE, SeaBOARD, and SeaTDD are either trademar ks or reg istered trade­marks of Se agate Technology LLC or on e of its subsidiaries. All other trademarks or register ed trade­marks are the property of their respective owners.

Seagate reser ves the right to change, without notice, product offerings or spe cifications. No part of this

publication may be reproduced in ny form without written permission of Seagate Technology LLC.

Revision status summary sheet

Revision Date Writer/Engineer Sheets Affected

Rev. A 08/27/1999 L. Newman/G. Velaski 1/1, v thru viii, 1-77.
Rev. B 03/24/2000 L. Newman/G. Velaski All.
Rev. C 06/20/2000 L. Newman/G. Velaski Page 51 (Section 9.5.2).
Rev. D 07/12/2000 K. Schweiss/G. Velaski Pages 7, 10, 25, and 46.
Rev. E 01/17/2001 L. Newman/G. Velaski Pages 30 and 44.

Notice.
Product Manual 83329476 is Volume 1 of a two volume document with the SCSI Interface inf ormation in

the Volume 2 SCSI Interface Product Manual, part number 75789509.
If you need the SCSI Interface information, order the Volume 2 Interface Manual, part number

75789509.

Cheetah 36LP Product Manual, Rev. E v

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 Electromagnetic susceptibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.2 Electromagnetic compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.3 Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3.0 General description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

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

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

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

3.4 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 characteristics (transparent to user). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

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

4.2.1 Access time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.2.2 Format command execution time (minutes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

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

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

4.4 Prefetch/multi-segmented cache control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4.5 Cache operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4.5.1 Caching write data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.5.2 Prefetch operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.1.4 Seek errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

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 Preventive maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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

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

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

5.2.7 Hot plugging Cheetah 36LP disc drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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

5.2.9 Drive Self Test (DST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.2.10 Product warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6.0 Physical/electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.1 AC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.2 DC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.2.1 Conducted noise immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6.2.2 Power sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6.2.3 12 V - Current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6.3 Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

6.4 Environmental limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

vi Cheetah 36LP Product Manual, Rev. E

6.4.1 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

6.4.2 Relative humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

6.4.3 Effective altitude (sea level). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

6.4.4 Shock and vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

6.4.5 Air cleanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

6.4.6 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

6.4.7 Electromagnetic susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

6.5 Mechanical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

7.0 Defect and error management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

7.1 Drive internal defects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

7.2 Drive error recovery procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

7.3 SCSI systems errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

8.0 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

8.1 Drive ID/option select header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

8.1.1 Notes for Figures 11, 12, and 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

8.1.2 Function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

8.2 Drive orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

8.3 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

8.3.1 Air flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

8.4 Drive mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

8.5 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

9.0 Interface requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

9.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

9.2 SCSI interface messages supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

9.3 SCSI interface commands supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

9.3.1 Inquiry Vital Product data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

9.3.2 Mode Sense data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

9.4 SCSI bus conditions and miscellaneous features supported . . . . . . . . . . . . . . . . . . . . . . . . .50

9.5 Synchronous data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

9.5.1 Synchronous 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 connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

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

9.7.1 Multimode—SE and LVD alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .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 Technology support services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

Cheetah 36LP Product Manual, Rev. E vii

List of Figures

Figure 1. Cheetah 36LP family drive (ST336704LW shown) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2. Cheetah 36LP family drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3. Typical ST336704 drive +12 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 4. Typical ST336704 drive +5 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 5. ST336704 DC current and power vs. input/output operations per second (SE) . . . . . . . . . . 24

Figure 6. ST336704 DC current and power vs. input/output operations per second (LVD) . . . . . . . . . 24

Figure 7. Locations of PCBA components listed in Table 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 8. Recommended mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 9. ST336704LW/LWV mounting configuration dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 10. ST336704LC/LCV mounting configuration dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 11. J6 jumper header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Figure 12. J5 jumper header (on LW and LWV models only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Figure 13. J2 option select header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Figure 14. Air flow (suggested) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Figure 15. LW/LWV model drive physical interface (68-pin J1 SCSI I/O connector). . . . . . . . . . . . . . . . 52

Figure 16. LC/LCV model drive physical interface (80-pin J1 SCSI I/O connector) . . . . . . . . . . . . . . . . 52

Figure 17. SCSI daisy chain interface cabling for LW/LWV drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Figure 18. Nonshielded 68 pin SCSI device connector used on LW/LWV drives . . . . . . . . . . . . . . . . . . 57

Figure 19. Nonshielded 80 pin SCSI “SCA-2” connector, used on LC/LCV drives . . . . . . . . . . . . . . . . . 58

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

Figure 21. Typical SE-LVD alternative transmitter receiver circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Cheetah 36LP Product Manual, Rev. E 1

1.0 Scope

This manual describes Seagate Technology®, Inc. Cheetah 36LP™ disc drives.
Cheetah 36LP drives support the small computer system interface (SCSI) as described in the ANSI SCSI SPI-

3 interface specifications to the extent described in this manual. The SCSI Interface Product Manual (part num­ber 75789509) describes general SCSI interface characteristics of this and other families of Seagate drives.

From this point on in this product manual the reference to Cheetah 36L P models is referred to as “the drive”
unless references to individual models are necessary.

Figure 1. Cheetah 36LP family drive (ST336704LW shown)

2 Cheetah 36LP Product Manual, Rev. E

Cheetah 36LP Product Manual, Rev. E 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 i ts host equip ment to provide adequ ate power and environment i n order to achieve opti­mum performance and compli ance with applicable industry and governm ental 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 se cure ly mo unte d i n o rd er to guaran tee the s pecified performance c har­acteristics. Mounting by bottom holes must meet the requirements of Section 8.4.

2.1 Standards

The Cheetah 36LP family complies with Seagate standards as noted in the appropriate sections of this Manual
and the Seagate SCSI Interface Product Manual, part number 75789509 (Vol. 2).

The Cheetah 36LP disc drive is a UL recognized component per UL1950, CSA certified to CSA C22.2 No. 950­M89, and VDE certified to VDE 0805 and EN60950.

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 suppli ed as a subassembly and is not su bject 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 req uirements in their syst em. Shielded I/O
cables may be required if the e nclosure does not provide ad equate sh ielding. If the I/O c ables are externa l 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 assembly, the drive is not required to meet any susceptibility per formance requ irements. It is
the responsibility of tho se integrating the dr ive within their sy stem s to perform thos e tests req uired and design
their system to ensu re that equipment operating in the sam e system as the drive or external to the s ystem
does not adversely affect the performance of the drive. See Section 5.1.1 and T able 2, DC power requirements.

2.2 Electromagnetic compliance

Seagate uses an independ ent laboratory to co nfirm compliance to the directives/standard(s) for CE Mark ing
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:

• Typical current use microprocessor

• 3.5-inch floppy disc drive

• Keyboard

• Monitor/display

• Printer

• External modem

• Mouse

Although the test system wi th this Seag ate mode l co mpl ie s to the dire cti ves/standa rd(s ), we cann ot gua rante e
that all systems will comply. The computer manufacturer or system i ntegrator shall confir m EMC complianc e
and provide CE Marking and C-Tick Marking for their product.

Electromagnetic compliance for the European Union

If this model has the CE Marki ng it complies with the European Union requirem ents of the Electromagnetic
Compatibility Direc tive 89/336/EEC o f 03 May 1989 as ame nded by Direct ive 92/31/EE C of 28 Ap r il 1992 an d
Directive 93/68/EEC of 22 July 1993.

4 Cheetah 36LP Product Manual, Rev. E

Australian C-Tick

If this model has the C-Tick Markin g it complies with the Australia/New Zea land Standard A S/NZS3548 199 5
and meets the Electro magnetic Compatibility (EMC) Framework requirements of Australia’s Spectrum Man­agement Agency (SMA).

2.3 Reference documents

Cheetah 36LP Installation Guide Seagate P/N 83329477
Safety and Regulatory Agency Spec ifi catio ns Seagate P/N 75789512
SCSI Interface Product Manual Seagate P/N 75789509

Applicable ANSI small computer system interface (SCSI) document numbers:

T10/1143D Enhanced SCSI Parallel Interface (EPI)
T10/1236D Primar y Comm and s-2 (S PC -2 )
T10/996D SCSI Block Commands (SBC)
T10/1157D SCSI Architectural Mode l-2 (S AM - 2)

T10/1302D SPI-3 (SCSI Parallel Interface version 3)
SFF-8046 Specification for 80-pin connector
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.

Cheetah 36LP Product Manual, Rev. E 5

3.0 General descript ion

Cheetah 36LP drives combine giant magnetoresistive (GMR) heads, partial response/maximum likelihood
(PRML) read channel el ectroni cs, embedd ed ser vo tech nology, and a wide Ultra160 SCSI interface to provide
high performance, high capaci ty data storage for a variety of syste ms incl uding en ginee ring work statio ns, net­work servers, mainframes, and supercomputers.

Ultra160 SCSI uses negotiated transfer rates. These transfer rates will occur only if your host adapter supports
these data transfer rates and is compatible with the required hardware requirements of the I/O circuit type. This
drive also operates at SCSI-1 and SCS I-2 data transfer rates for backward compatibility with non -Ultra/Ultra2/
Ultra160 SCSI host adapters.

Table 1 lists the features that differentiate the two Cheetah 36LP models.

Table 1: Drive model number vs. differentiating features

Number

Model number

of active
heads I/O circuit type [1]

Number of I/O
connector pins

Number of I/O
data bus bits

ST336704LW
ST336704LWV

ST336704LC
ST336704LCV

12 Single-ended (SE) and low volt-

age differential (LVD)

12 Single-ended (SE) and low volt-

age differential (LVD)

68 16

80 16

[1] See Section 9.6 for details and definitions.
The drive records and recovers data on approximately 3.3-inch (84 mm) non-removeable discs.
The drive suppor ts the Small Computer System Interface (SCSI) as descr ibed in the ANSI SCSI-2/SCSI-3

interface specifications t o the extent described in this manual (volume 1), which defines the product perfor­mance characteris tics of the Cheetah 36LP family of drives, and the S CSI Interface Product Manual (volume

2), part number 7578 9509, which describes the genera l interface 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 disasse m­ble the HDA and do not attempt to service items in the seal ed enc losure (head s, media, ac tuator, etc.) as this
requires special facilities. The drive contains no replaceable parts. Opening the HDA voids your warranty.

Cheetah 36LP drives use a dedicated landing zone at the innermost radius of the media to eliminate the possi­bility of destroying or degrading da ta by landing in the d ata zone. The drive automa tically goes to the 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 ha ndl ing . T he shi ppi ng lock au toma tic al ly di se nga ges whe n power is applied to the drive and
the head load process begins.

Cheetah 36LP drives decode track 0 location data from the servo data embedded on each surface to eliminate
mechanical transducer adjustments and related reliability concerns.

A high-performance actuator assembly with a low-inertia, balanced, patented, straight-arm design provides
excellent performance with minimal power dissipation.

6 Cheetah 36LP Product Manual, Rev. E

Figure 2. Cheetah 36LP family drive

Cheetah 36LP Product Manual, Rev. E 7

3.1 Standard features

The Cheetah 36LP family has the following standard features:

• Integrated Ultra160 SCSI controller

• Multimode SCSI drivers and receivers—single-ended (SE) and low voltage differential (LVD)

• 16 bit I/O data bus

• Asynchronous and synchronous data transfer protocol (supports Ultra160 transfer rate)

• Firmware downloadable via SCSI interface

• Selectable even byte sector sizes from 512 to 2,064 bytes/sector

• Programmable sector reallocation scheme

• Flawed sector reallocation at format time

• Programmable auto write and read reallocation

• Reallocation of defects on command (post format)

• ECC maximum burst correction length of 240 bits with a guaranteed burst correction length of 233 bits.

• Sealed head and disc assembly

• No preventative maintenance or adjustment required

• Dedicated head landing zone

• Embedded servo design

• Self diagnostics performed when power is applied to the drive

• Zoned bit recording (ZBR)

• Vertical, horizontal, or top down mounting

• Dynamic spindle brake

• 4,096 kbyte data buffer (16,384 kbytes on LWV and LCV models)

• Hot plug compatibility (Section 9.6.4.2 lists proper host connector needed) for LC and LCV model drives

• Drive Self Test (DST)

• Supports SCSI bus fairness

3.2 Media characteristics

The media used on the dr ive has a di ameter of a pproximately 3 .3 in ches (8 4 mm). The alumi num substrat e is
coated with a thin film magneti c mat eria l, overcoated with a propr iet ar y prote ctive layer for improved durability
and environmental protection.

3.3 Performance

• Supports industry standard Ultra3 SCSI interface

• Programmable multi-segmentable cache buffer (see Section 4.5)

• 10,033 RPM spindle. Average latency = 2.99 ms

• Command queuing of up to 64 commands

• Background processing of queue

• Supports start and stop commands (spindle stops spinning)

3.4 Reliability

• 1,200,000 hour MTBF

• LSI circuitry

• Balanced low mass rotary voice coil actuator

• Incorporates industry-standard Self-Monitoring, Analysis and Reporting Technology (S.M.A.R.T.)

• 5-year warranty

8 Cheetah 36LP Product Manual, Rev. E

3.5 Unformatted and 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:

Formatted
data block size

512 bytes/sector [1] Unformatted

ST336704 0445DCC9h (36.7 GB) [2] 43.7 GB

Notes.

[1] Sector size se lectable at format time. Users having the necessar y equipmen t may modify the data block

size before issuing a format co mmand and obtain different formatted capa cities than those listed. See
Mode Select Command and Format Command in the SCSI Interface Product Manual, part number

75789509.

[2] User available capacit y depends on spare r eallocation schem e selected, the number o f data tracks per

sparing zone, and the number of alternate sectors (LBAs) per sparing zone.

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 SCS I Interface Product Manual, par t number 7578 9509. Refer to the
Parameter list block descriptor number of blocks field. A value of zero in the number of blocks field indic ates
that the drive shall not change the capacity it is curr ently form atted to have. A number in the number of blocks
field that is less than the ma ximum number of L BAs changes the total drive capacity to the value in the block
descriptor number of blocks field. A value greater th an the max imum number of LB As is round ed down to th e
maximum capacity.

3.7 Factory installed accessories

OEM Standard dr ives are sh ipped wit h the Ch eetah 36LP Instal lation G uide, par t number 83329477, and the
Safety and Regulatory Agency Specifications, part number 75789512 (unless otherwise specified). The factory

also ships with the drive a small bag of jumper plugs used for the J2, J5, and J6 option select jumper headers.

3.8 Options (factory instal led)

All customer request ed options are incorporate d during production or packaged at the manufacturin g 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 sector size requested.

• Single unit shipping pack. The drive is norm ally shipped in bulk pa ckaging to provide maximum protec tion

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.

• The Chee tah 36LP Installatio n Guide , par t num ber 8332 9477, is us ually included wi th each standard OEM

drive shipped, but extra copies may be ordered.

• The Safety and Regulatory Agency Specifications, par t number 75789512, is usually incl uded 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.

Cheetah 36LP Product Manual, Rev. E 9

4.0 Performance characteristics

4.1 Internal drive characteristics (transparent to user)

ST336704

Drive capacity 36.7 GByte (formatted, rounded off values)
Read/write heads 12
Bytes/track 215,248 Bytes (average, rounded off values)
Bytes/surface 3,035 Mbytes (unformatted, rounded off values)
Tracks/surface (total) 14,100 Tracks (user accessible)
Tracks/inch 18,145 TPI
Peak bits/inch 334 KBPI
Internal data rate 280-427 Mbits/sec (variable with zone)
Disc rotational speed 10,033 r/min (+
Average rotational latency 2.99 msec

4.2 SCSI performance characteristics (visible to user)

The values given in Section 4.2.1 app ly to all mode ls of the Ch eetah 36LP family unless o therwise spec ified.
Refer to Section 9.10 and to the SC SI Interface Product Manual, part number 75 789509, for addit ional timin g
details.

0.5%)

4.2.1 Access time [5]

Including controller overhead
(without disconnect) [1] [3]

Drive level Drive level

Not including controller overhead
(without disconnect) [1] [3]

Read Write Read Write

msec msec
Average – Typical [2] 5.4 6.2 5.2 6.0
Single Track – Typical [2] 0.8 1.1 0.6 0.9
Full Stroke – Typical [2] 11.2 11.9 11.0 11.7

4.2.2 Format command execution time (minutes) [1]

ST336704

Maximum (with verify) 120
Maximum (no verify) 60

4.2.3 Generalized performance characteristics

Minimum sector interleave 1 to 1

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

Min. [3]* 26.7 MByte/sec
Avg. [3] 33.0 MByte/sec
Max. [3] 40.2 MByte/sec

SCSI interface data transfer rate (asynchronous):

Maximum instantaneous one byte wide 5.0 Mbytes/sec [4]
Maximum instantaneous two bytes wide 10.0 Mbytes/sec [4]

Synchronous formatted transfer rate

Ultra2 SCSI Ultra160 SCSI

In low voltage differential (LVD) interface mode 5.0 to 80 Mbytes/sec 5.0 to 160 Mbytes/sec

10 Cheetah 36LP Product Manual, Rev. E

Sector Sizes:

Default 512 byte user data blocks
Variable 512 to 2,064 bytes per sector in even number of bytes per sector.

If n (number of bytes per sector) is odd, then n-1 will be used.

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

the spare sectors per sparing zone reallocation scheme.)
Average rotational latency 2.99 msec

Notes for Section 4.2.

[1] Execution time measured fr om receipt of the last byte of the Command Descriptor Block (CDB) to the

request for a Status Byte Tr ansfer to the Initiator (excluding connect/disconnect).

[2] Typical access times are measur ed under nominal co ndition s of temperat ure, voltage, and horizont al or i-

entation as measured on a representative sample of drives.
[3] Assumes no errors and no sector has been relocated.
[4] Assumes system ability to support the rates listed and no cable loss.
[5] Access time = controller overhead + average seek time.

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

4.3 Start/stop time

After DC power at no minal voltage h as been appl ied, the d r ive becom es rea dy withi n 24 sec onds if the Mo tor
Start Opti on is disabled (i.e. the motor star ts as soon as the power has bee n applied). If a recoverable error
condition is detected during the start sequence, the drive executes a recovery procedure which may cause the
time to become rea dy to exceed 24 seconds. Dur ing spin up to ready time the dr ive responds to s ome com­mands over the SCSI interface in less than 3 seconds after application of power. Stop time is less than 30 sec­onds from removal of DC power.

If the Motor Star t Option is en abled, the inter nal cont roller accep ts the comm ands list ed in the SCSI Interface
Product Manual less than 3 seconds aft er DC power has been appli ed. After the Motor Start Co mmand has
been received the d rive becomes ready for nor mal opera tions withi n 24 seco nds typica lly (excluding an error
recovery procedure). The Mo tor Start Comm and can also be used to comm and the drive to stop the spindle
(see SCSI Interface Product Manual, part number 75789509).

Negligible

There is no power control switch on the drive.

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 buffer storage space when
it is used in cache operations. To select prefetch and cache features the host sends the Mode Select command
with the proper values in the ap plicable bytes in Mode Page 08h (see SCSI Interface Product Manual, part
number 75789509). Pre fetch and cache operation are independent features from the s tandpoint that each is
enabled and disabled independentl y via the Mode S elect com mand. However, in actual operation the prefetch
feature overlaps cache operation somewhat as is noted in Section 4.5.1 and 4.5.2.

All default cache and prefetch Mode pa rameter values (Mode Page 08h) for standard OEM versions of this
drive family are given in Tables 8.

4.5 Cache operation

In general, 3,600 Kbytes (14,399 kbytes of the 16, 384 kbytes on LWV and LCV units) of the physical buffer
space in the drive can be used as storage spac e for cache operations. The buffer can be divi ded into logical
segments (Mode Select Page 08h, byte 13) from which data is read and to which data is written. The drive sup­ports a maximum of 64 cache segments. The drive maintains a table of logical block disk medium addresses of
the data stored in each segme nt of the buffer. If cache operation is enabled (RCD bit = 0 in Mode Page 08h,

Cheetah 36LP Product Manual, Rev. E 11

byte 2, bit 0. See SCSI Interface Product Manual, part numb er 75789509), da ta requested by the hos t with a
Read command is retrieved from the buffer (if it is there), before any disc access is initiated. If cache operation
is not enabled, the buffer (still segment ed with re quired number of segme nts) is s till use d, but only as ci rcular
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 it. The retrieved data merely passes thr ou gh some buffer segment on the way to the host. On a ca ch e
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 as sociated with Mode p age 02h (disconne ct/reconnect contr ol) in
the SCSI Interface Product Manual.

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

Case A -

1. Drive transfers to the initiator the first LB reque ste d plu s al l su bs equ ent co nti guo us LBs that ar e already in

2. When the requested LB is reached that is not in any cache segment, the drive fetches it and any remaining

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

Case B -

1. The drive fetches the requested LBs from the disc and transfers them into a segment, and from there to the

2. If the prefetch feature is enabled, refer to Section 4.5.2 for operation from this point.
Each buffer segment is actually a s elf-contained circular storage (wrap-around oc curs), the le ngth of which is

an integer number of disc medium sectors. The wrap-around capability of the individual segments greatly
enhances the buffer’s over all performance as a cache storage, allowing a wide range of user selectable config­urations, which includes their use in the prefetch operation (if enabled), even when cache operation is disabled
(see Section 4.5.2) . The number of se gments is set dynam ically by the drive and can not be set by the host.
The size in Kbytes of each segme n t is no t r eported by the Mode Sen se co mma nd pa ge 0 8h, bytes 14 a nd 15 .
The value 0XFFFF is always repor ted. If a size specificatio n 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 page 00h (byte 2,
bit 1) is set to one, the drive resp onds as it does for any attempt to change unchang eable parameters (see
SCSI Interface Product Manual, part number 75789509).

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

the cache. This data may be in multiple segments.

requested LBs from the disc an d puts them in a s egment of the cache. The dr ive transfers the remainin g
requested LBs from the ca che to t he host in accorda nce with the disconn ect/r econn ect speci fication men­tioned above.

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

host in accordance with the disconnect/reconnect specification referred to in case A.

4.5.1 Caching write data

Write caching is a wr ite op eration by the dr ive that makes use of a drive buffer storage area where the data t o
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), then data written to the medium is retained in the cache to be made avail­able for future read cache hits. The s ame buffer space and segme ntat ion is u sed a s set up for read func tions.
The buffer segmentation scheme is set up or changed independently, having nothing to do with the state of
RCD. When a write co mmand is issued, if RCD=0 , the cache is first checked to see if any logical blocks that
are to be writte n are already stored in the cach e from a previous read or write comman d. If there are, the
respective cache segments are cleared. The new data is cached for subsequent Read commands.

If the number of wri te data lo gical blocks exceeds t he size of the segment b eing w ritten i nto, 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 the drive may return GOOD status on a write 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 data to the medium, and GOOD status has already been returned, a deferred error will be
generated.

12 Cheetah 36LP Product Manual, Rev. E

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.

Tables 8 show Mode default settings for the drives.

4.5.2 Prefetch operation

If the Prefetch feature is enabled, data in conti guous lo gical blocks on the disc i mmedia tely b eyond that which
was requested by a Read comman d can be retri eved 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 th e prefetch operation us es the buffer as a cache, findin g the r equ es ted data i n
the buffer is a prefetch 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 am ount of prefetch data to optimize s ystem 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 dri ve crosses a cyl inder bounda r y to fetch more data o nly if the Discontinuity
(DISC) bit is set to one in bit 4 of byte 2 of Mode parameters page 08h.

Whenever prefetch (read look-ahead) is enabled ( enabled by DRA = 0), it opera tes und er the co ntrol of ARLA
(Adaptive Read Look-Ahead). If the host uses software interleave, ARLA enables prefetch of contiguous blocks
from the disc when it sense s that a prefetch hit will l ikely occur, even if two consecutive read operations were
not for physically contiguous blocks of data (e.g., “software interleave”). ARLA disables prefetch when it
decides that a prefetch hit will not li kely occu r. If the host is not usin g so ftware interleave, and if two sequential
read operations are not for contiguous blocks of data, ARLA dis ables prefetch, but as long as sequential read
operations request contiguous blocks of data, ARLA keeps prefetch enabled.

Cheetah 36LP Product Manual, Rev. E 13

5.0 Reliability specifications

The following reliability spe cifications assume correct hos t/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 sector in 10
MTBF 1,200,000 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 command.

• Errors caused by media d efects or hos t system failures are exclude d from er ror rate comp utat ions. Refer to
Section 3.2, “Media Characteristics.”

• Assume random data.

8

seeks

12

bits transferred (OEM default settings)

15

bits transferred (OEM default settings)

21

bits transferred

5.1.1 Environmental interference

When evaluating systems operatio n under condit ions of Ele ctromagnetic Interference (EMI), the performanc e
of the drive within the s ystem shall b e consi dered acce ptable if the dr ive does not g enerate an unre coverable
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 dr ive or sys tem rec overy pro cedur es wit hou t opera tor inte rven-

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 verified as being written correctly on
the media.

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

5.1.3 Write errors

Write errors can occur as 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 beca use of a n equipm ent mal functi on in the dr ive, the error is classi fied
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).

5.1.4 Seek errors

A seek error is de fin ed as a failure o f t he drive to position the h eads to the addressed track. Ther e sh all b e n o
more than ten recoverable seek errors in 10

8

physical seek operations. After detecting an init ia l se ek err or, the

drive automatically per forms an error recover y process. If the error r ecovery process fails, a seek posi tioning

14 Cheetah 36LP Product Manual, Rev. E

error (15h) is repor ted wit h a Medium err or (3h) or Har dware error (4h) repo rt ed in the Sense Key. This is an
unrecoverable seek error. Unrecoverable seek errors are classified as failures for MTBF calculatio ns. Refer to
the SCSI Interface Product Manual, part number 75789509, for Request Sense information.

5.2 Reliability and service

You can enhance the reliability of Cheetah 36LP disc drives by ensuring that the drive receives adequate cool­ing. Section 6.0 pr ovides tempe rature me asurements and othe r information that may be used to en hance th e
service life of the drive. Section 8.3.1 provides recommended air-flow information.

5.2.1 Mean time between failure

The production d isc drive shall achieve an MTBF o f 1,200,000 hours when operated in an environment that
ensures the case temperatures specified in Section 6.4.1, T able 3 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 may degrade product reliability.

The MTBF target is specified as device power-on hours (POH) for all drives in service per failure.
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 servic e. Each dis c dr ive shal l have accumulated a t leas t nine month s of o peration. Data sha ll be calc ulated
on a rolling average base for a minimum period of six months.

MTBF is based on the following assumptions:

• 8,760 power-on hours per year.

• 250 average on/off cycles per year.

• Operations at nominal voltages.

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

exceeded.
Drive failure means any stoppage or substandard performance caused by drive malfunction.
A S.M.A.R.T. pre dictive failure indic ates th at the d rive is deter ioratin g to an immin ent failure an d is co nside red

an MTBF hit.

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 90% of power-on hours.

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

exceeded.

Month 1 2,500 PPM

Month 2 1,650 PPM

Month 3 1,200 PPM

Month 4 1,000 PPM

Month 5 890 PPM

Month 6 840 PPM

Month 7 805 PPM

Failure rate is calculated as follows:

• No system-induced failures are counted

• Based on 1,200,000 MTBF and 720 power-on hours per month

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

Cheetah 36LP Product Manual, Rev. E 15

5.2.3 Preventive maintenance

No routine scheduled preventive maintenance shall be required.

5.2.4 Service life

The drive shall have a useful ser vic e life of five years. Depot repair or repl acement of major parts is per m itted
during the lifetime (see Section 5.2.5).

5.2.5 Service philosophy

Special equipmen t is requir ed to repair the drive HDA. In order to achi eve the above service life, repairs must
be performed only at a proper ly equip ped and staffed ser vice and repair facility. Troubleshooting and repair of
PCBs in the field i s not recommended, be cause of the extensive diagnostic eq uipment required for effective
servicing. Also, there are no spare parts available for this drive. Drive warranty is voided if the HDA is opened.

5.2.6 Service tools

No special tools are requi red for site instal lat ion or recomm ended 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 Cheetah 36LP disc drives

The ANSI SPI-3 (T10 /1302D) documen t defines the physical requi rements for removal and inser tion of SCS I
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 - All bus devices powered off during removal or insertion
Case 2 - RST signal asserted continuously during removal or insertion
Case 3 - Current I/O processes not allowed during insertion or removal
Case 4 - Current I/O process allowed during insertion or removal, except on the device being changed
Seagate Cheetah 36LP di s c dr i ves support all four hot pluggin g ca se s. Pr ovision sha ll be ma de by the s yste m

such that a device being inserted ma kes power and ground connecti ons pri or to the co nnection o f any device
signal contact to the bus. A device being re moved shall maintain power and groun d connecti ons after the dis­connection 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 processe s for the SCSI device bein g inser ted or removed shall b e quiescent. A ll SCSI devices on th e
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 (LV D) mode, then all I/O pr ocesses for all devices on the bus must be compl eted, 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 Res et, 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 (H VD) drivers and receivers and devices wit h
SE, LVD, or multimode drivers and rec eivers on the same SCSI bus since the co mmon 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 co me to a complete st op prior to comple tely removing the dr ive from the cabinet
chassis. Use of the Stop Spin dle co mmand o r partial with drawal of the dr ive, enough to be dis connec ted fro m
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, "Shock and vibration" in this manual.

16 Cheetah 36LP Product Manual, Rev. E

5.2.8 S.M.A.R.T.

S.M.A.R.T. is a n acronym for Self -Monitor ing A nalysis and Repor ti ng Technology. This technology is inte nded
to recognize conditions that indi cate a dri ve failure and is designed to provide suff icient war ning of a failure to
allow data back-up before an actual failure occurs.

Note.

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

Each attribute ha s bee n s el ec ted to mo nit or a sp ec ifi c s et of failure c ond itio n s in the operating performa nce of
the drive, and the thresholds are optimized to minimize “false” and “failed” predictions.

Controlling S.M.A.R.T.

The operating mode of S.M.A.R.T. is controlled by the DEXCPT bit and the PERF bi t of the “Informational
Exceptions Control Mode Page” (1Ch). Th e DEXCPT bit is us ed to enable or disable 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 nor m al re ad/wr ite operatio ns. When t he PER F bit is set, th e dr ive is consi dered to be in
“On-line Mode Only” and will not perform off-line functions.

The process of measuring off-line attributes and saving data can be forced by the Rezero Unit command. Forc­ing S.M.A.R.T. will reset the timer so that the next scheduled 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 loggi ng process will oc cur. 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, forc­ing S.M.A.R.T by the Rezero Unit 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 save parameters once every two hours subject to an idle per iod on the
SCSI bus. The process of m easuring off-line attr ibute data and saving data to th e disc is u ninterrup table and
the maximum delay is summarized below:

Maximum processing delay

On-line only delay Fully enabled delay
DEXCPT = 0, PERF = 1 DEXCPT = 0, PERF = 0

S.M.A.R.T. delay times 50 milliseconds 300 milliseconds

Reporting control

Reporting i s controlled in the Informational Excep tions Control Page (1Ch). Subj ect to the repor ting method,
the firmware will is su e a 01- 5D0 0 s ense c od e to the hos t. T h e err or c ode is pr eserved through bus resets an d
power cycles.

Determining rate

S.M.A.R.T. monito rs the rat e at whi ch error s occu r and signals a pr edictive failure if the rate of degraded error
rate increases to an una cc ept able level. To det ermine rate, error events are logged and c omp ar ed t o th e num­ber of total operations for a given attr ibute. The inter val defines the number of operations over which to m ea­sure the rate. The counter that keeps track of the c urrent number of operations is referred to as the I nterval
Counter.

S.M.A.R.T. measu res error rate, hence for each attribute the oc currence of an error is rec orded. A counter
keeps track of the number of errors for the current interval. This counter is referred to as the Failure Counter.

Error rate is simply the number of errors per ope ration. The algorithm that S.M.A.R.T. uses to recor d rates of
error is to set thresholds for the number of errors and the interval. If the number of errors exceeds the threshold
before the interval expires, then the error rate is cons idered to be u nacceptable. If the numbe r of errors d oes
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 starts over.

Cheetah 36LP Product Manual, Rev. E 17

Predictive failures

S.M.A.R.T. signals predicti ve failures when the dr ive is perform ing una ccep tably for a period of tim e. The fir m­ware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accom­plish this, a counte r is incremen ted whenever the error rate is una cceptable and de cremented (n ot 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 Drive Self Test (DST)

Drive Self Test (DST) is a technology designed to recognize drive fault conditions that qualify the drive as a
failed unit. DST validates the functionality of the drive at a system level.

There are two test coverage options implemented in DST:

1. Extended test

2. Short text
The most thorough option is the extended test that performs various tests on the drive and scans every logical

block address (LBA) of the drive. The short test is time-restricted and limited in length—it does not scan the
entire media surface, but does some fundamental tests and scans portions of the media.

If DST encounters an error during either of these tests, it reports a fault condition. If the drive fails the test,
remove it from service and return it to Seagate for service.

5.2.9.1 DST Failure Definition

The drive will present a “diagnostic failed” condition through the self-tests results value of the diagnostic log
page if a functional failure is encountered during DST. The channel and servo parameters are not modified to
test the drive more stringently, and the number of retries are not reduced. All retries and recovery processes
are enabled during the test. If data is recoverable, no failure condition will be reported regardless of the number
of retries required to recover the data.

The following conditions are considered DST failure conditions:

• Seek error after retries are exhausted

• Track-follow error after retries are exhausted

• Read error after retries are exhausted

• Write error after retries are exhausted.

Recovered errors will not be reported as diagnostic failures.

5.2.9.2 Implementation

This section provides all of the information necessary to implement the DST function on this drive.

5.2.9.2.1 State of the drive prior to testing

The drive must be in a ready state before issuing the Send Diagnostic command. There are multiple reasons
why a drive may not be ready, some of which are valid conditions, and not errors. For example, a drive may be
in process of doing a format, or another DST. It is the responsibility of the host application to determine the “not
ready” cause.

While not technically part of DST , a Not Ready condition also qualifies the drive to be returned to Seagate as a
failed drive.

A Drive Not Ready condition is reported by the drive under the following conditions:

• Motor will not spin

• Motor will not lock to speed

• Servo will not lock on track

• Drive cannot read configuration tables from the disc

In these conditions, the drive responds to a Test Unit Ready command with an 02/04/00 or 02/04/03 code.