Seagate ST373454LC operation manual

Users Guide

Cheetah 15K.4 SCSI

ST3146854 ST373454 ST336754

Users Guide

Cheetah 15K.4 SCSI

ST3146854 ST373454 ST336754

Publication number: 100220456, Rev. D

May 2005

Seagate, Seagate Technology, and the Seagate logo ar e registered trademar ks of Seagate Technology LLC. SeaTools, SeaFONE, SeaBOARD, and SeaTDD are either registered trademarks or tradema rks of Seaga te Technolog y LLC. Other p roduct names are regist ered trademarks or trademarks of their owners.

Seagate reserves the right to ch ange, witho ut notice, product offerings or spec ifications . No

part of this publication may be reproduc ed in any form w ithout wr itte n per mi ssio n of Seagate

Technology LLC.

Revision status summary sheet

Revision Date Sheets Affected

Rev. A 06/30/04 i-iii, 1-93. Initial release. Rev. B 07/14/04 Page 9. Rev. C 01/13/05 Pages 9, 12, 25, 26, 28, 29, 30, 31, 32, 33, and 38. Rev. D 05/04/05 Pages 8, 12, and 37.

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.3 Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.0 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.1 Standard features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.2 Media characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.3 Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.4 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.5 Formatted capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.5.1 Programmable drive capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.6 Factory installed accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.7 Options (factory installed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.8 Accessories (user installed). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4.0 Performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.1 Internal drive characteristics (transparent to user) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.2 SCSI performance characteristics (visible to user) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.2.1 Access time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.2.2 Format command execution time (minutes). . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.2.3 Generalized performance characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.3 Start/stop time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.4 Prefetch/multi-segmented cache control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.5 Cache operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.5.1 Caching write data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.5.2 Prefetch operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.5.3 Optimizing cache performance for desktop and server applications . . . . . . . . . 15

5.0 Reliability specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.1 Error rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.1.1 Recoverable Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.1.2 Unrecoverable Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.1.3 Seek errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2 Reliability and service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2.1 Mean time between failure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2.2 Preventive maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2.3 Hot plugging Cheetah 15K.4 SCSI disc drives. . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2.4 S.M.A.R.T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.2.5 Thermal monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

5.2.6 Drive Self Test (DST). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

5.2.7 Product warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

6.0 Physical/electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.1 AC power requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.2 DC power requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.2.1 Conducted noise immunity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.2.2 Power sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.2.3 Current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.3 Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6.4 Environmental limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Cheetah 15K.4 SCSI Product Manual, Rev. D i

6.4.1 Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

6.4.2 Relative humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

6.4.3 Effective altitude (sea level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

6.4.4 Shock and vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

6.4.5 Air cleanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

6.4.6 Corrosive environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

6.4.7 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

6.4.8 Electromagnetic susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

6.5 Mechanical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

7.0 Defect and error management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

7.1 Drive internal defects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

7.2 Drive error recovery procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

7.3 SCSI systems errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7.4 Background Media Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7.4.1 Media Pre-Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

8.0 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

8.1 Drive ID/option select header. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

8.1.1 Notes for Figures 18, 19, and 20.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

8.1.2 Function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

8.2 Drive orientation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

8.3 Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

8.4 Drive mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

8.5 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

9.0 Interface requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

9.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

9.2 SCSI interface messages supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

9.3 SCSI interface commands supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

9.3.1 Inquiry Vital Product data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

9.3.2 Mode Sense data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

9.4 SCSI bus conditions and miscellaneous features supported. . . . . . . . . . . . . . . . . . . . . . . 63

9.5 Synchronous data transfer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

9.5.1 Synchronous data transfer periods supported . . . . . . . . . . . . . . . . . . . . . . . . . . 64

9.5.2 REQ/ACK offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

9.6 Physical interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

9.6.1 DC cable and connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

9.6.2 SCSI interface physical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

9.6.3 SCSI interface cable requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

9.6.4 Mating connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

9.7 Electrical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

9.7.1 Multimode—SE and LVD alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

9.8 Terminator requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

9.9 Terminator power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

9.10 Disc drive SCSI timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

9.11 Drive activity LED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

10.0 Seagate Technology support services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

ii Cheetah 15K.4 SCSI Product Manual, Rev. D

List of Figures

Figure 1. Cheetah 15K.4 SCSI family drive (ST3146854LC shown) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2. Typical ST3146854 drive +12V LVD current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 3. Typical ST3146854 drive +5 V LVD current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 4. Typical ST373454 drive +12V LVD current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 5. Typical ST373454 drive +5V LVD current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 6. Typical ST336754 drive +12V LVD current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 7. Typical ST336754 drive +5V LVD current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 8. ST3146854 DC current and power vs. IOPS (SE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 9. ST3146854 DC current and power vs. IOPS (LVD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 10. ST373454 DC current and power vs. IOPS (SE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 11. ST373454 DC current and power vs. IOPS (LVD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 12. ST336754 DC current and power vs. IOPS (SE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 13. ST336754 DC current and power vs. IOPS (LVD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 14. Locations of the HDA temperature check point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 15. Recommended mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Figure 16. LW mounting configuration dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Figure 17. LC mounting configuration dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Figure 18. J6 jumper header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Figure 19. J5 jumper header (on LW models only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Figure 20. J2 option select header (on LW models only). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Figure 21. Air flow (suggested) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Figure 22. LW model drive physical interface (68-pin J1 SCSI I/O connector) . . . . . . . . . . . . . . . . . . . . 66

Figure 23. LC model drive physical interface (80-pin J1 SCSI I/O connector). . . . . . . . . . . . . . . . . . . . . 66

Figure 24. SCSI daisy-chain interface cabling for LW drives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Figure 25. Nonshielded 68-pin SCSI device connector used on LW drives . . . . . . . . . . . . . . . . . . . . . . 71

Figure 26. Nonshielded 80-pin SCSI SCA-2 connector used on LC drives. . . . . . . . . . . . . . . . . . . . . . . 72

Figure 27. Typical SE-LVD alternative transmitter receiver circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Cheetah 15K.4 SCSI Product Manual, Rev. D iii

1.0 Scope

This manual describes Seagate® Technology LLC, Cheetah® 15K.4 SCSI disc drives.

Cheetah 15K.4 SCSI driv es support the small computer system interface (SCSI) as described in the ANS I

SCSI SPI-4 interface specifications to the extent described in this manual. The SCSI Interface Product Manual

(part number 75789509) descr ibes general SCSI interface charac te ri st ic s of this and othe r fam ilies of Se agat e

drives.

From this point on in this product ma nual the reference to Chee tah 15K.4 SCSI models is referr ed to as “the

drive” unless references to individual models are necessary.

Figure 1. Cheetah 15K.4 SCSI family drive (ST3146854LC shown)

Cheetah 15K.4 SCSI Product Manual, Rev. D 1

2 Cheetah 15K.4 SCSI Product Manual, Rev. D

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 host equ ipment to provide adequate power and envi ronment in order to achi eve opti

mum performance and co mpliance with applicable indus try and governmental regulations. Special attention

must be given in the areas of safety, power distribution, shielding, audible noise control, and temperature regu

lation. In particula r, the drive must b e s ecur el y mou nted i n o rde r to gua ra nte e th e s pe ci fie d p er formance char-

acteristics. Mounting by bottom holes must meet the requirements of Section 8.4.

2.1 Standards

The Cheetah 15K.4 SC SI fa mily c ompli es w ith Seag ate standards as note d in the approp riate sectio ns o f this

Manual and the Seagate SCSI Interface Product Manual, part number 75789509, Volume 2.

The Cheetah 15K.4 SCSI disc drive is a UL recognized c omponent per UL195 0, CSA certifie d to CSA C22.2

No. 950-95, and VDE certified to VDE 0805 and EN60950.

2.1.1 Electromagnetic compatibility

The drive, as delivered , is designed for system integrati on and installation into a suitable encl osure prior to

use. As such the d rive is supplied as a subassembly and is not subject to Subpart B of Part 15 of the FCC

Rules and Regulation s nor the Radio Interference Reg ulations of the Canadian Departm ent of Communica

tions.

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 Regula

tions of the Canadian Department of Communications when properly packaged. However, it is the user’s

responsibility t o assure that the drive mee ts the appropriate EMI re quirements in their system. S hielded I/O

cables may be requir ed if the en closure do es not provi de adequate shieldi ng. If the I/O cab les are exte rnal to

the enclosure, shielded cables should be used, with the shields grounded to the enclosure and to the host con

troller.

2.1.2 Electromagnetic susceptibility

As a component a ssembly, the drive is not requ ired to meet any susc eptibi lity perfor mance requ irements. It is

the responsibilit y of those integrating the driv e wit hin their systems to pe rfo rm those tests required a nd des ig n

their system to ensure th at equipment operating in the same sy stem as the drive or external to the syste m

does not adversely affect the performance of the drive. See Table

Cheetah 15K.4 SCSI Product Manual, Rev. D 3

12, DC power requirements.

2.2 Electromagnetic compliance

Seagate uses an indepe ndent laboratory to co nfirm compliance to the di rectives/standard(s) for CE Marking and C-Tick Marking. The drive was tested in a representative system for typical applications. The selected sys tem 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 with this Seagate model complies to the directives/standard(s), we cannot guarantee

that all systems will comply. The computer manufacturer or system integrator shall confirm EMC compliance and provide CE Marking and C-Tick Marking for their product.

Electromagnetic compliance for the European Union

If this model has the CE Marking it co mplies with the European Union requirements of the El ectromagnetic Compatibility Directive 89 /336/EEC of 03 May 1989 as amend ed by Dir ective 92 /31/ EEC of 28 Apri l 1992 an d Directive 93/68/EEC of 22 July 1993.

Australian C-Tick

If this model has th e C-Tick Marking it complies with the Austr alia/New Zeal and Standard AS/NZS3548 199 5 and meets the Electromagnet ic Compatibility (EMC) Framework requi rements of Australia’s Spectrum Man agement Agency (SMA).

Korean MIC

If this model has the Korean Ministry of Information and Communication (MIC) logo, it complies with paragraph 1 of Article 11 of the Electromagnetic Compatibility (EMC) Control Regulation and meets the Electroma gnetic Compatibility Framework requirements of the Radio Research Laborator y (RRL) Ministry of Information and Communication Republic of Korea.

This drive has been t ested and c omplies with the Elec tromagne tic Interfer ence/El ectromagne tic Susc eptibility (EMI/EMS) for Class B products.

Taiwanese BSMI

If this model has the Chinese National Standard (CNS) 13438 marking, it complies with Chinese National Standard (CNS) 13438 an d meets the Electromagnetic Compatibil ity (EMC) Framework requir ements of the Taiwanese Bureau of Standards, Metrology, and Inspection (BSMI).

4 Cheetah 15K.4 SCSI Product Manual, Rev. D

2.3 Reference documents

Cheetah 15K.4 SCSI Installation Guide Seagate P/N 100220463

Safety and Regulatory Agency Specifications 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) T10/1416D Primary Commands-2 (SPC -3 ) T10/1417D SCSI Block Commands (SBC-2) T10/1157D SCSI Architectural Model-2 (SAM-2) T10/1302D SPI-3 (SCSI Parallel Interface version 3)

T10/1365D SPI-4 (SCSI Parallel Interface version 4) SFF-8451 Specification for SCA-2 Unshielded Connections Package Test Specification Seagate P/N 30190-001 (under 100 lb.) Package Test Specification Seagate P/N 30191-001 (over 100 lb.) Specification, Acoustic T est Requirements, and Procedures Seagate P/N 30553-001 In case of conflict between this document and any referenced document, this document takes precedence.

Cheetah 15K.4 SCSI Product Manual, Rev. D 5

6 Cheetah 15K.4 SCSI Product Manual, Rev. D

3.0 General description

Cheetah 15K.4 SCSI dr ives combine giant magnetoresistive (GMR) heads, partial respon se/maximum likelihood (PRML) read channel electr onics, embedded servo technology, and a wide Ultra320 SCSI interface to provide high perform ance, high capacity data storage fo r a variety of syste ms including engine ering worksta tions, network servers, mainframes, and supercomputers.

Ultra320 SCSI use negot iated trans fer rates . These tr ansfer ra tes will occu r only if your hos t adapter su pports these data transfer rates and is compatible with the required hardware requirements of the I/O circuit type. This drive also operates at S CSI-1 and SCSI- 2 data tran sfer rat es for backw ard compatib ility with non- Ultra/ Ultra2/ Ultra160/Ultra320 SCSI host adapters.

Table 1 lists the features that differentiate the Cheetah 15K.4 SCSI models.

Table 1: Drive model number vs. differentiating features

Model number

ST3146854LW ST373454LW ST336754LW

ST3146854LC ST373454LC ST336754LC

Number of active heads I/O circuit type [1]

8 4

Single-ended (SE) and low voltag e differential (LVD)

2 8

Single-ended (SE) and low voltag e differential (LVD)

Number of I/O connector pins

[1] See Section 9.6 for details and definitions. The drive records and recovers data on approximately 70 mm non-removable discs. The drive supports the Small Computer System Interface (SCSI) as described in the ANSI SCSI interface

specifications to the extent desc ribed in th is m anual (v olume 1), whi ch d efines the produ ct pe rforman ce c har acteristics of the Cheetah 15K.4 SCSI family of drives, and the SCSI Interface Product Manual (volume 2), part number 75789509, which desc ribes the general interface characteri stics of this and other families of Seagate SCSI drives.

The drive’s interface sup ports mul tip le ini tia tor s , disc onn ec t/r econn ec t, se lf- c onfig u ring h os t so ftware, a nd l og ical block addressing.

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.

Never disassemble the HDA a nd do not at tempt to service ite m s i n t he se aled enclosure ( hea ds, m edi a, ac tu ator, etc.) as this requires specia l facilities. The d rive contains no replac eable parts. Opening the HDA voids your warranty.

Cheetah 15K.4 SCSI Product Manual, Rev. D 7

Cheetah 15K.4 SCSI drives use a dedicated landing zone at the innermost radius of the media to eliminate the possibility of d estroying or degrading d ata by landing in the data zone. The drive automatically 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 handl in g. T he s hip pin g lo ck auto mat ic all y dis eng age s whe n powe r i s ap plied to the drive and the head load process begins.

A high-performance actuator assembly with a low-inertia, balanced, patented, straight-arm design provides excellent performance with min im al powe r diss ipation .

3.1 Standard features

The Cheetah 15K.4 SCSI family has the following standard features:

• Integrated Ultra320 SCSI interface.

• 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

• Firmware downloadable via SCSI interface

• Selectable even byte sector sizes from 512 to 528 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 burst correction length of up to 288.

• 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

• 8,192 kbytes data buffer

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

• Drive Self Test (DST)

• Supports SCSI bus fairness

3.2 Media characteristics

The media used on the drive has an alumi num sub st rat e co ated with a thin fi lm magn eti c mater ia l, over coate d with a proprietary protective layer for improved durability and environmental protection.

8 Cheetah 15K.4 SCSI Product Manual, Rev. D

3.3 Performance

• Supports industry standard Ultra320 SCSI interface

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

• 15k RPM spindle. Average latency = 2.0 msec

• Command queuing of up to 64 commands

• Background processing of queue

• Supports start and stop commands (spindle stops spinning)

3.4 Reliability

• 1,400,000 hour MTBF

• Increased LSI circuitry integration

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

• 5-year warranty

3.5 Formatted capacities

Standard OEM models are formatted to 512 bytes per block. The sector size is selectable at format time. Users having the necessary equipm ent may mo dify the data block s ize before issuing a fo rmat comm and and obtain different formatted capacities than those listed.

To provide a stable target capacity environment and at the same time provide users with flexibility if they choose, Seagate recommends product planning in one of two modes:

1. Seagate designs specify capacity points at certain sector sizes that Seagate guarantees current and future

products will meet. We recommend custo mers use this capacity in their project pl anning, as it ensures a

stable operating point with backw ard and forward c ompatibi lity from gener ation to generati on. The curren t

guaranteed operating points for this product are:

ST336754 ST373454 ST3146854

Sector Size

Decimal Hex Decimal Hex Decimal Hex

512 71,687,372 445DCCC 143,374,744 88BB998 286,749,488 11177330 514 70,512,692 433F034 141,025,384 867E068 282,050,768 10CFC0D0 520 70,197,546 42F212A 140,395,092 85E4254 280,790,184 10BC84A8 522 68,914,176 41B8C00 137,834,496 8373000 275,656,704 106E3000 524 68,766,592 4194B80 137,577,184 83342E0 275,154,368 106685C0 528 68,165,733 4102065 136,331,467 82040CB 272,662,935 10408197

2. Seagate drives also may be used at the maximum available capacity at a given sector size, but the excess

capacity above the guaranteed level will vary between 10K and 15K families and from generation to gener

ation, depending on how each sector si ze actually for mats out for zone frequencies an d splits over serv o

bursts. This added capaci ty potent ial may range from 0.1 to 1.3 percent above th e guarant eed capacities

listed above. Us ing th e dr ives in th is mann er gi ves the ab so lute m aximu m capacity poten tial, but the user

must determine if the extra ca pacity potential is useful, or whether their assurance of backward and for

ward compatibility takes precedenc e.

3.5.1 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 Interface Product Manual. Refer to the Parameter list block descriptor number of blocks field. A value of zero in the number of blocks field indicates that the drive shall not

Cheetah 15K.4 SCSI Product Manual, Rev. D 9

change the capacity it i s currently forma tted to have. A number in the n umber of block s field that is less than the maximum numbe r of LBAs changes th e total driv e capacity t o the val ue in the block des criptor number of blocks field. A value greater than the maximum number of LBAs is rounded down to the maximum capacity.

3.6 Factory installed accessories

OEM Standard drives are shipped with the Cheetah 15K.4 Installation Guide, part number 100220463, and the Safety and Regulatory Agency Specifications, part number 75789512 (unless otherwise specified). The factory

also ships with the drive a small b ag of jumper pl ugs use d for the J2, J5, and J6 option sele ct ju mper heade rs on LW models only.

3.7 Options (factory installed)

All customer req uested options are inc orporated during produ ction or packaged at t he manufacturing facil ity 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 normall y shipped in bulk packagin g to provide maximum pro tection 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 Cheetah 15K.4 Installation Guide, part number 100220463, is usually included with each standard OEM drive shipped, but extra copies may be ordered.

• The Safety and Regulatory Agency Specifications, part nu mber 75789512, is usually included with each standard OEM drive shipped, but extra copies may be ordered.

3.8 Accessories (user installed)

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

• Single unit shipping pack.

10 Cheetah 15K.4 SCSI Product Manual, Rev. D

4.0 Performance characteristics

4.1 Internal drive characteristics (transparent to user)

ST3146854 ST373454 ST336754

Drive capacity 146.8 73.4 36.7 GByte (formatted, rounded off values) Read/write heads 8 4 2 Bytes/track 471,916 471,916 471,916 Bytes (average, rounded off values) Bytes/surface 18,351 18,351 18,351 Mbytes (unformatted, rounded off val-

ues) Tracks/surface (total) 50,864 50,864 50,864 Tracks (user accessible) Tracks/inch 85,000 85,000 85,000 TPI Peak bits/inch 628 628 628 KBPI Internal data rate 685-1,142 685-1,142 685-1,142 Mbits/sec (variable with zone) Disc rotational speed 15k 15k 15k r/min Average rotational latency 2.0 2.0 2.0 msec

4.2 SCSI performance characteristics (visible to user)

The values given in Section 4.2.1 apply to all models of the Cheetah 15K.4 SCSI family unless otherwise specified. Refer to Section 9.10 and to the SCSI Interface Product Manual for additional timing details.

Cheetah 15K.4 SCSI Product Manual, Rev. D 11

4.2.1 Access time

Not including controller overhead (msec) Read Write

1,2

Average Typical 3.5 4.0 Single Track Typical 0.2 0.4 Full Stroke Typical 7.4 7.9

1. Typical access times are measured under nominal conditions of temperature, voltage, and horizontal orientation as measured on a representative sample of drives.

2. Access to data = access time + latency time.

4.2.2 Format command execution time (minutes) [1]

ST3146854 ST373454 ST336754

Maximum (with verify) 90 60 30 Maximum (no verify) 45 30 15

4.2.3 Generalized performance characteristics

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

Minimum [3] 685 Mbits/sec Maximum [3] 1,142 Mbits/sec

Sustainable disc transfer rate:

Minimum [3] 58 Mbytes/sec Maximum [3] 96 Mbytes/sec

SCSI interface data transfer rate (asynchronous):

Maximum instantaneous one byte wide 5.0 MBytes/sec [3] Maximum instantaneous two bytes wide 10.0 MBytes/sec [3]

Synchronous transfer rate

In low voltage differential (LVD) interface mode 5.0 to 320 MBytes/sec

Sector Sizes: Default 512 byte user data blocks Variable 512 to 528 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

Negligible

the spare sectors per sparing zone reallocation scheme) Average rotational latency 2.00 msec

Notes for Section 4.2. [1] Execution time measu red from receipt of the last by te of the Command Descriptor B lock (CDB) to the

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

12 Cheetah 15K.4 SCSI Product Manual, Rev. D

[2] Assumes no errors and no sector has been relocated. [3] Assumes system ability to support the rates listed and no cable loss.

4.3 Start/stop time

After DC power at nomi nal voltage h as b een ap plied , the drive becom es rea dy wi thin 20 seco nds i f the Motor Start Option is disabled (i.e., the motor starts as soo n as the power has b een applied). If a recov erable error condition is detected during the start sequence, the drive executes a recovery procedure which may cause the time to become ready to exceed 20 seco nds. During spin up to ready time the drive responds to s ome com mands over the SCSI interface in less than 3 seconds after application of power. Stop time is 30 seconds from removal of DC power.

If the Motor Start Option is enabled , the interna l contro ller acc epts the command s liste d in the S CSI Inter face Product Manual less than 3 seconds after DC power has been appli ed. After the Motor Start Command has been received the dri ve becomes re ady for norma l operations withi n 20 second s typically (excluding a n error recovery procedur e). The Motor Start Command can also be u sed to command t he drive to stop the spi ndle (see the SCSI Interface Product Manual).

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 v alues in the applicabl e bytes in Mode Page 08h (see the SCSI Interf ace Product Manual). Prefetch and cache ope ration 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 somewhat as is noted in

Section 4.5.1 and 4.5.2.

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

19.

4.5 Cache operation

In general, 7,077 kbytes of the physical buffer space in the drive can be used as storage space for cache operations. The buffer can be d ivided into logical segments (Mode Selec t 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 dis c medium a ddres ses of th e data stored i n eac h segm ent of the buffer. If cache opera tion is enabled (RCD bit = 0 in Mode Page 08h, byte 2, bit 0. See SCSI Interface Product Manual), data requested by the hos t with a Read command is r etrie ved from the buffer ( if i t i s th er e) , b efo re an y di sc ac ce ss is initiated. If c ache oper ation is no t enabl ed, the buffer (stil l se gmented with r equired num ber of s egments) is still used, but only as circular buffer segments during disc medium read operations (disregarding Prefetch operation for the momen t). 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 through some buffer seg ment on the way to the h ost. On a ca che mis s, all data transfe rs to the hos t are in acc ordance wi th buffer-full ratio rules. On a cach e hit the drive igno res the buffer-full r atio rules . See e xplanati ons assoc iated 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 LBs that are already in the cache. This data may be in multiple segments.

2. When the requested LB is reached that is not in any cache segment, the drive fetches it and any remaining requested LBs from th e disc and puts them in a segment of the cache. The drive transfers the rem aining

Cheetah 15K.4 SCSI Product Manual, Rev. D 13

requested LBs from the ca che t o the host in accorda nce with the disc onnect/r econn ect speci ficatio n mentioned above.

3. If the prefetch feature is enabled, refer to Se cti on 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 LBs from the disc and transfers them into a segm ent, and from there to the host in accordance with the disconnect/reconnect specification referred to in case A.

2. If the prefetch feature is enabled, refer to Se cti on 4.5. 2 for operation from this point.

Each buffer segment is act ually a self-containe d circular sto rage (wrap-arou nd occurs), the length of which is an integer number 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 configurations, which includes their use in the prefetch operat ion (if enabled) , even when cache ope ration is disab led (see

4.5.2). The number of segmen ts is set dyna mical ly by the d rive and can not no rmally be set by the h ost (it ca n

be set using the PM bit as describe d in Section 4.5.3). 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 ho st in a M ode Select c ommand (byte s 14 and 15) no new segm ent si ze is set up b y the drive, and if the STRICT bit in Mode page 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).

4.5.1 Caching write data

Write caching is a write operation by the d rive th at makes u se of a dr ive b uffer s to rage ar ea wher e the da ta to be written to the medium is stored in one or more segments while the drive performs the write command.

Section

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 an d segme ntation is use d as set up for read func tions. The buffer segmentation s cheme is set up or changed independently, having nothing to do with the state of RCD. When a write command is issued, i f RCD=0, the cache is first checke d to see if any logical blocks tha t are to be written are a lready stored in the cache f rom 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 write data logi cal block s exceeds th e size of the s egment being wr itten into, whe n 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.

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 19 show Mode default settings for the drives.

4.5.2 Prefetch operation

If the Prefetch fea ture i s ena bl ed, data in co nti guo us lo gic al b lock s on t he d is c immediately beyond tha t whi c h was requested by a Read command can be re trieved and stored in the buffer for i mmediate transfer from the buffer to the host on subseque nt Read com mands that request t hose logica l block s (this is tr ue 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 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 bi t = 0 enables prefetch. S ince data that is prefetc hed replaces

14 Cheetah 15K.4 SCSI Product Manual, Rev. D

data already in some buffer segment(s ), the hos t can lim it the amou nt of pr efet ch data to optimi z e syst em per formance. The max prefetch field (bytes 8 a nd 9) limits the amount of pref etch. The drive does not use the Prefetch Ceiling field (bytes 10 and 11).

During a prefetch operati on, the dri ve crosses a cylinde r boundary to fetch mor e data only if th e Discontinu ity (DISC) bit is set to one in bit 4 of byte 2 of Mode parameters page 08h.

Whenever prefetch ( re ad loo k-ah ead) is enabled ( ena ble d b y DRA = 0), i t o per at es und er th e c on tro l of A RLA (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 physically con tiguou s blocks of da ta (e.g., “software i nterleave”) . ARLA disab les prefetc h when it decides that a prefetch hit will not likely occur. If the host is not using software interleave, and if two sequential read operations are no t for c ontigu ous bloc ks of data, ARLA d isables prefetc h, but as long as se quentia l read operations request contiguous blocks of data, ARLA keeps prefetch enabled.

4.5.3 Optimizing cache performance for desktop and server applications

Desktop and server applications require different drive caching operations for optimal performance. This means it is difficult to provide a single configuration that meets both of these needs. In a desktop environment, you want to con figure the cache to respond q uickly to repetitive ac cesses of multiple s mall segmen ts of data without taking the time to “look ahea d” to the next conti guous segmen ts of data. In a server environ ment, you want to configure the cac he to provide large volumes of seque ntial data in a non-repetitive manner. In this case, the ability of the cache to “look ahead” to the next contiguous segmen ts of sequential data is a good thing.

The Performance Mode (PM) bit contr ols the way the drive switches the cache buffer into different modes o f segmentation. In “server mode” (PM bit = 0), the drive can dynamically cha nge the number of cache buffer segments as needed to opt imize the performa nce, based on the command st ream from the hos t. In “desktop mode” (PM bit = 1), the number of segments is maintained at the value defined in Mode Page 8, Byte 13, at all times (unless changed by using a Mode Select command). For additional information about the PM bit, refer to the Unit Attention Param eters page (00h) of the Mode Sense command (1Ah) in the SCSI Interfac e Product Manual, part number 75789509.

Cheetah 15K.4 SCSI Product Manual, Rev. D 15

16 Cheetah 15K.4 SCSI Product Manual, Rev. D

5.0 Reliability specifications

The following reliabi lity specifications assume cor rect host/drive operational interfa ce, including all interface timings, power supply voltages, environmental requirements and drive mounting constraints (see Section

Seek Errors Read Error Rates [1]

Recovered Data Less than 10 errors in 1012 bits transferred (OEM default settings) Unrecovered Data Less than 1 sector in 1015 bits transferred (OEM default settings) Miscorrected Data Less than 1 sector in 1021 bits transferred MTBF 1,400,000 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.

Less than 10 in 108 seeks

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).

• Errors caused by host system failures are excluded from error rate computations.

• Assume random data.

• Default OEM error r ecovery settings are applied. Thi s includes AWRE, ARRE, full read retries, fu ll write

retries and full retry time.

8.4).

5.1.1 Recoverable Errors

Recovereable errors are those detected and corrected by the drive, and do not require user intervention. Recoverable Data errors will use co rrection, although ECC on -the-fly is not c onsidered for purposes of recov-

ered error specifica tio ns. Recovered Data error rate is determine d using read bits transfer red for recove rable errors occurring dur ing a

read, and using write bits transferred for recoverable errors occurring during a write.

5.1.2 Unrecoverable Erro rs

Unrecoverable Data Error s (Sense Ke y = 03h) ar e specified at l ess than 1 se ctor in erro r per 1015 bits transferred. Unrecoverable Data Errors resulting from the same cause are treated as 1 error for that block.

Cheetah 15K.4 SCSI Product Manual, Rev. D 17

5.1.3 Seek errors

A seek error is defined as a fail ur e of the dr i ve to pos it ion the heads to the address ed tra ck. Aft er dete cti ng a n initial seek error, the drive automatically performs an error recovery process. If the error recovery process fails, a seek positioning error (Error code = 15h or 02h) will be reporte d with a Hardware error (04h) in t he Sense Key. Recoverab le seek er rors are sp ecifi ed at Less than 10 erro rs in 10

seeks. Unrecoverable seek errors

(Sense Key = 04h) are classified as drive failures.

5.2 Reliability and service

You can enhan ce the reliability of Che etah 15K.4 SCSI disc drives by ensuring that the drive r eceives adequate cooling. Sectio n 6.0 provides tem perature measurements and other in formation that may be used to enhance the service life of the drive. Section 8.3 provides recommended air-flow information.

5.2.1 Mean time between failure

The production disc dri ve shall achieve an MTBF of 1,400,000 hours when o perated in an environmen t that ensures the HDA case t emperatures specified in Section the specificatio n limits of the ope rating en vironm ent will no t affect MTBF pe rformance. Continua l or sustaine d operation at case temperatures above the values shown in Section

The MTBF target is specified as device power-on hours (POH) for all drives in service per failure.

6.4 are not exceeded. Short-term ex cursions up to

6.4.1 may degrade product reliability.

MTBF per measurement period = Estimated power-on operating hours in the 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. Ea ch dis c drive shall hav e accu mulate d at leas t nine mon ths of ope ratio n. Data shall be cal culated 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 prov ide adequate coolin g to ensure the case temperatures specified in S ection 6.4.1 are not

exceeded. Drive failure means any stoppage or substandard performance caused by drive malfunction. A S.M.A.R.T. predictive fail ure indic ates that the dri ve is deter iorating to an imm inent failu re and is co nside red

an MTBF hit.

5.2.2 Preventive maintenance

No routine scheduled preventive maintenance shall be required.

5.2.3 Hot plugging Cheetah 15K.4 SCSI disc drives

The ANSI SPI-4 document defines the physical requirements for removal and insertion of SCSI devices on the SCSI bus. Four cas es are addressed. The cases a re 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

18 Cheetah 15K.4 SCSI Product Manual, Rev. D

Case 4 - Current I/O process allowed during insertion or removal, except on the device being changed Seagate Cheetah 15K.4 SCSI disc drives support all four hot plugging cases . Provision shall be made by the

system such tha t a dev ice being inserted ma kes p ower a nd g ro und c onn ect ion s prior t o the connection of any device signal co ntact to the bus. A device bein g removed shall maintain p ower and grou nd connecti ons after the disconnection of any device signal contact from the bus (see SFF-8451 Specification for SCA-2 Unshielded Connections).

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 th e SCSI device bein g inserted or remov ed shall be quiesc ent. All SCSI devices on the bus shall have receivers that conform to the SPI-4 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 fo r all devic es on the bus must be co mplete d, and th e bus qu i esced, before attempting to hot plug. Following the insertion of the newly installed device, the SCSI host adapter must issue a Bus Reset, fol lowed by a sy nchronous transfer ne gotiation . Failure to per form 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 shoul d not mix devices with high vol tage differential (HVD) driv ers and r eceivers a nd devices with SE, LVD, or multimode drivers and receivers on the same SCSI bu s since the comm on mode vo ltages in the HVD environment may not be controlled to safe levels for SE and LVD devices (see ANSI SPI-4).

The disc drive sp indle must come to a complete s top prior to completely removing the drive from the cabinet chassis. Use of th e Stop Spindle command or partial withdr awal of the drive, e nou gh to b e disco nnecte d 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

5.2.4 S.M.A.R.T.

S.M.A.R.T. is an acronym for Se lf-Moni toring Ana lysis and Repor ting Technology. This technology is intende d to recognize conditions that indicate drive degradation and is designed to provide sufficient warning of a failure to allow data back-up before an actual failure occurs.

Note. The firmwa re will monitor s pecific attribute s for degradation over time but canno t predict instanta-

neous drive failures.

Each attribute monit ors a specif ic set of co nditions in the operating pe rformance of the drive, and the thresholds are optimized to minimize “false” 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 bit of the “ Informational Exceptions Control Mo de Page” (1Ch) . The DEXCPT bit i s used to ena ble or dis able 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/w rite oper ation s. When th e PERF bit is s et, the drive i s consi dered to b e 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.

Section 6.4.4, "Shock and vibration" in this manual.

The drive can be interrogated by the host to determine the time remaining before the next scheduled measurement and data logging process will occu r. 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, forc ing S.M.A.R.T by the Rezero Unit command will reset the timer.

Cheetah 15K.4 SCSI Product Manual, Rev. D 19

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 driv e wi ll measure and save parameter s on ce ever y tw o hou rs subj ec t to an idl e p er iod on th e SCSI bus. The process of measu ring off-line attribute data and saving data to the disc is uninterruptable and the maximum delay is summarized below::

Maximum processing delay

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

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

42 milliseconds

Fully-enabled delay DEXCPT = 0, PERF = 0

163 milliseconds

Reporting control

Reporting is contr olled in the Inform ational Exceptions Co ntrol Page (1Ch). Subject to the repo rting method, the firmware will is sue a 01-5D00 sense code to th e h ost . T he erro r co de i s pr es erve d th ro ugh bus res ets an d power cycles.

Determining rate

S.M.A.R.T. monitors the rate at which erro rs occur and signal s a pred ictive fai lure if the rate of degrad ed error rate increases to an un acce ptab le le ve l. To determine rate, error events are logged and compar ed to the num ber of total operations for a given attribut e. The interval defines the number of operatio ns over which to measure the rate. The counter that kee ps track of the current number of oper ations is referred to as the Interval Counter.

S.M.A.R.T. measures error rate, hence for each attribute the occur rence of an error is recorded. 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 simpl y the number of errors per operation. T he algorithm t hat S.M.A. R.T. uses to reco rd 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 i s considered to be un acceptable. If the num ber of errors does not exceed the threshold before the interval expires, then the error rate i s considered to be acceptable. In either case, the interval and failure counters are reset and the process starts over.

Predictive failures

S.M.A.R.T. signals predict ive failures when the drive is perfor ming unacc eptably for a period of time. Th e firmware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accomplish this, a counter is incre mented wheneve r the error rate is unacc eptable and decremen ted (not to exceed zero) whenever the error rate is acceptable. This counter is referred to as the Failure History Counter. There is a separate Failure History Cou nter for each attribute. Should the c ount er con tin ual ly be i ncre men ted s uc h tha t it reaches the predictive threshold, a predictive failure is signaled.

5.2.5 Thermal monitor

Cheetah 15K.4 SCSI drives implement a temperature warning system which:

1. Signals the host if the temperature exceeds a value which would threaten the drive.

2. Signals the host if the temperature exceeds a user-specified value.

3. Saves a S.M.A.R.T. data frame on the drive which exceed the threatening temperature value. A temperature sensor monito rs the drive temperature and is sues a warning over the int erface when the tem-

perature exceeds a s et threshol d. The temper ature is measured at power-up an d then at te n-minute intervals after power-up.

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