seagate CHEETAH 15K.4 FC product manual

Cheetah 15K.4 FC

ST3146854FC ST373454FC ST336754FC

Cheetah 15K.4 FC

ST3146854FC ST373454FC ST336754FC

Publication number: 100220449, Rev. C

May 2005

Seagate, Seagate Technology, and the Seagate logo are registered trademar ks of Seagate Technology LLC. SeaTools, SeaFONE, SeaBOARD, and SeaTDD are either registered trademarks or tradema rks of Seaga te Technology LLC. Othe r product 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 1/1, v-viii, 1-96. Initial release. Rev. B 07/14/04 Page 9. Rev. C 05/04/05 Pages 2,11, 25, 26, 36, 38, 50, 51, 57, and 75 - 79.

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 compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.2 Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

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

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

3.2 Media description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 Factory-installed options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.8 User-installed accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

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

4.1 Internal drive characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.2 Seek performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.2.1 Access time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

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

4.2.3 General performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.3 Start/stop time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.4 Prefetch/multi-segmented cache control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

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

5.1.4 Interface errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

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

5.2.1 Mean time between failure (MTBF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

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

5.2.3 Hot plugging the drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

6.2.2 Power sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

6.2.3 Current profiles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

6.3 Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

6.4 Environmental limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Cheetah 15K.4 FC Product Manual, Rev. C i

6.4.1 Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.4.2 Relative humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

6.4.3 Effective altitude (sea level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

6.4.4 Shock and vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

6.4.5 Air cleanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.4.6 Corrosive environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.4.7 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

6.4.8 Electromagnetic susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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

7.0 Defect and error management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.1 Drive internal defects/errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.2 Drive error recovery procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.3 FC-AL system errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

7.4 Background Media Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

7.4.1 Media Pre-Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

8.0 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

8.1 Drive ID/option selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

8.2 LED connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

8.2.1 J6 connector requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

8.3 Drive orientation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

8.4 Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

8.5 Drive mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

8.6 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

9.0 Interface requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

9.1 FC-AL features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

9.1.1 Fibre Channel link service frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

9.1.2 Fibre Channel task management functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

9.1.3 Fibre Channel task management responses . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

9.1.4 Fibre Channel port login . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

9.1.5 Fibre Channel port login accept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

9.1.6 Fibre Channel Process Login. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

9.1.7 Fibre Channel Process Login Accept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

9.1.8 Fibre Channel fabric login. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

9.1.9 Fibre Channel fabric accept login. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

9.1.10 Fibre Channel Arbitrated Loop options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

9.2 Dual port support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

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

9.3.1 Inquiry data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

9.3.2 Mode Sense data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

9.4 Miscellaneous operating features and conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

9.5 FC-AL physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

9.5.1 Physical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

9.5.2 Connector requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

9.5.3 Electrical description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

9.5.4 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

9.5.5 FC-AL transmitters and receivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

9.5.6 Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

9.5.7 Fault LED Out. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

9.5.8 Active LED Out. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

9.5.9 Enable port bypass signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

9.5.10 Motor start controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

9.5.11 SEL_6 through SEL_0 ID lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

9.5.12 Device control codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

ii Cheetah 15K.4 FC Product Manual, Rev. C

9.6 Signal characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

9.6.1 TTL input characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

9.6.2 LED driver signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

9.6.3 Differential PECL output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

9.6.4 Differential PECL input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

10.0 Seagate Technology support services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Cheetah 15K.4 FC Product Manual, Rev. C iii

iv Cheetah 15K.4 FC Product Manual, Rev. C

List of Figures

Figure 1. Cheetah 15K.4 FC family disc drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2. Typical ST3146854FC drive, 2 Gbit, +12V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 3. Typical ST3146854FC drive, 2 Gbit, +5V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 4. Typical ST373454FC drive +12V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 5. Typical ST373454FC drive +5V current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 6. Typical ST336754FC drive +12V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 7. Typical ST336754FC drive +5V current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 8. ST3146854FC DC current and power vs. input/output operations per second . . . . . . . . . . . 30

Figure 9. ST373454FC DC current and power vs. input/output operations per second . . . . . . . . . . . . 31

Figure 10. ST336754FC DC current and power vs. input/output operations per second . . . . . . . . . . . . 32

Figure 11. Locations of the HDA temperature check point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 12. Recommended mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 13. Mounting configuration dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Figure 14. Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Figure 15. LED indicator connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Figure 16. Air flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Figure 17. Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Figure 18. Port bypass circuit physical interconnect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Figure 19. FC-AL SCA device connector dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Figure 20. J6 connector dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Figure 21. FC-AL transmitters and receivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Figure 22. Transmit eye diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Figure 23. Receive eye diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Cheetah 15K.4 FC Product Manual, Rev. C v

1.0 Scope

This manual describes Seagate Technology® LLC, Cheetah® 15K.4 FC (Fibre Channel) disc drives.

Cheetah 15K.4 FC drives support the Fibre Channel Arbitrated Loop and SCSI Fibre Channel Protocol specifi-

cations to the extent desc ribed in this manual. The F ibre Channel Interface Ma nual (part number 77767496)

describes the gener al Fibre Channe l Arbitrated Loop char acteristics o f this and other Seagate Fibre Channel

drives.

Figure 1. Cheetah 15K.4 FC family disc drive

Cheetah 15K.4 FC Product Manual, Rev. C 1

2 Cheetah 15K.4 FC Product Manual, Rev. C

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 8.5.

2.1 Standards

The Cheetah 15K.4 FC family comp lies with Seagate standards as noted in th e appropriate sections of this

manual and the Seagate Fibre Channel Interface Manual, part number 77767496.

The Cheetah 15K.4 FC disc drive is a UL recognized component per UL1950, CSA certified to CAN/CSA

C22.2 No. 950-95, and VDE certified to VDE 0805 and 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.

2.1.1.1 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 dr iv e wit hin the ir s y ste ms to perform those tests req uire d 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

2, DC power requirements.

Cheetah 15K.4 FC Product Manual, Rev. C 3

2.1.2 Electromagnetic compliance

Seagate uses an inde pendent laborato ry to confirm comp liance with the directives/standa rds for CE Markin g 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 with the directives/standards, we cannot guarantee

that all systems will comply. The computer manufacturer or system integrator shall confirm EMC compliance and provide the appropriate 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.

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 FC Product Manual, Rev. C

2.2 Reference documents

Cheetah 15K.4 FC Installation Guide Seagate part number: 100220460

Fibre Channel Interface Manual Seagate part number: 77767496

ANSI Fibre Channel Documents

X3.230-1994 FC Physical and Signaling Interface (FC-PH)

X3.297.1997 FC-PH-2 Fibre Channel Physical and Signaling Interface-2

X3.303.1998 FC-PH-3 Fibre Channel Physical and Signaling Interface-3

X3.272-1996 FC Arbitrated Loop (FC-AL)

X3.269-1996 Fibre Channel Protocol for SCSI (FCP)

NCITS TR-19 Private Loop SCSI Direct Attach (PLDA)

NCITS TR-20 Fabric Loop Attachment (FC-FLA)

SFF-8045 Specification for 40-pin SCA-2 Connector with Parallel Selection

SFF-8067 Specification for 40-pin SCA-2 Connector with Bidirectional

Enclosure Services Interface

ANSI Small Computer System Interface (SCSI) Documents

X3.131-1994 (SCSI-2)

X3.270-1996 (SCSI-3) Architecture Model

NCITS 305-199X (SCSI-3) Enclosure Services

Specification for Acoustic Test Requirement and Procedures

Seagate part number: 30553-001

Package Test Specification Seagate P/N 30190-001 (under 100 lb.)

Package Test Specification Seagate P/N 30191-001 (over 100 lb.)

In case of conflict between this document and any referenced document, this document takes precedence.

Cheetah 15K.4 FC Product Manual, Rev. C 5

6 Cheetah 15K.4 FC Product Manual, Rev. C

3.0 General description

Cheetah 15K.4 FC drives com bi ne gi ant m agn etores i stive (GMR) heads, partial respo nse/ma xi mu m li ke li hoo d

(PRML) read channel ele ctronics , embedded ser vo technolog y, and a Fibre Channel interface to pr ovide hig h

performance, high capac ity data storage f or a variety of systems including engineering wo rkstations, netwo rk

servers, mainframes, and supercomputers. Cheetah 15K.4 FC drives also support 2-Gbit Fibre Channel which

can transfer data at up to 200 Mbytes per second and 400 Mbytes per second in dual-loop configurations.

Cheetah 15K.4 FC drives supp ort the Fibre C hannel Ar bitrated Loo p (FC-AL) an d SCSI Fi bre Channel P roto-

col as described in the ANSI specifications, this document, and the Fibre Channel Interface Manual (part num-

ber 77767496) which describes the general interface characteristics of this drive. Cheetah 15K.4 FC drives are

classified as intelligent peripherals and provide level 2 conformance (highest level) with the ANSI SCSI-1 stan

dard.

Never disassemble the HDA a nd do not at tempt to service ite ms in the sealed enclo su re (hea ds , m edi a, ac tu-

ator, etc.) as this requires sp ecial facilities. The drive does not contain user-replaceab le parts. Opening the

HDA for any reason voids your warranty.

Cheetah 15K.4 FC drives u se a dedicated l anding zone a t the innermo st radius o f the media to el iminate the

possibility of destroying or degrading data by landing in the data zone. The heads automatically go to the land

ing zone when power is removed from the drive.

An automatic shipping lock prevents potential damage to the heads and discs that results from movement dur-

ing shipping and h andling. The shipping lock disengages and th e head load process be gins when power is

applied to the drive.

The drives also use a high-performance actuator assembly with a low-inertia, balanced, patented, straight arm

design that provides excellent performance with minimal power dissipation.

Cheetah 15K.4 FC Product Manual, Rev. C 7

3.1 Standard features

Cheetah 15K.4 FC drives have the following standard featur es :

• 2-Gbit Fibre Channel interface. For 2 gigabit operation, the block size must be divisable by 8.

• Integrated dual port FC-AL controller

• Concurrent dual port transfers

• Support for FC arbitrated loop, private and public attachment

• Differential copper FC drivers and receivers

• Downloadable firmware using the FC-AL interface

• Supports SCSI enclosure services via interface connector

• 128-deep task set (queue)

• Supports up to 32 initiators

• Drive selection ID and configuration options are set on the FC-AL backpanel or through interface commands. Jumpers are not used on the drive.

• Supports SCSI Enclosure Services through the interface connector

• Fibre Channel worldwide name uniquely identifies the drive and each port

• User-select a ble lo gi cal bl o ck si ze (512 to 528 bytes per logical block). For 2 gigabit operation, the block size must be divisable by 8.

• Selectable frame sizes from 256 to 2,112 bytes

• Industry standard 3.5-inch low profile form factor dimensions

• Programmable logical block reallocation scheme

• Flawed logical block reallocation at format time

• Programmable auto write and read reallocation

• Reed-Solomon error correction code

• Sealed head and disc assembly (HDA)

• No preventive maintenance or adjustments required

• Dedicated head landing zone

• Automatic shipping lock

• Embedded Grey Code track address to eliminate seek errors

• Self-diagnostics performed at power on

• 1:1 interleave

• Zone bit recording (ZBR )

• Vertical, horizontal, or top down mounting

• Dynamic spindle brake

• 8,192 Kbyte data buffer (see Section 4.5).

• Embedded servo design

• Reallocation of defects on command (Post Format)

• Fibre Channel interface transports SCSI protocol

3.2 Media description

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 FC Product Manual, Rev. C

3.3 Performance

• Programmable multi-segmentable cache buffer

• 200 Mbytes/sec maximum instantaneous data transfers per port

• 15k RPM spindle; average latency = 2.0 msec

• Command queuing of up to 128 commands

• Background processing of queue

• Supports start and stop commands (spindle stops spinning)

• Adaptive seek velocity; improved seek performance

3.4 Reliability

• 1,400,000 hour MTBF

• Increased LSI circuitry integration

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

• Dithering

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:

ST336754FC ST373454FC ST3146854FC

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 139,463,602 8500BB2 279,041,740 10A1D6CC 524 68,766,592 4194B80 137,577,184 83342E0 275,154,368 106685C0 528

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 FC Product Manual, Rev. C 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-install ed accessories

OEM standard drives are shipped with the Cheetah 15K.4 FC Installation Guide (part number 100220460) and the Safety and Regulatory Agency Specifications, part number 75789512 (unless otherwise specified).

3.7 Factory-install ed options

You may order the follow ing items which are incorpor ated at the manufacturing fa cility during production or packaged 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 shippi ng pack. The drive is normally shipped in bulk packag ing to provide maximum p rotection 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 FC Installation Guide, part number 100220460, is usually inc luded with eac h standard OEM drive shipped, but extra copies may be ordered.

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

3.8 User-installed accessories

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

• Evaluation kit, part number 73473641. This kit provides an adapter card (“T-card”) to allow cable connections for two FC ports and DC power.

• Single-unit shipping pack.

10 Cheetah 15K.4 FC Product Manual, Rev. C

4.0 Performance characteristics

This section provides detailed information concerning performance-related characteristics and features of Cheetah 15K.4 FC drives.

4.1 Internal drive characteristics

ST3146854FC ST373454FC ST336754FC Drive capaci ty 146.8 73.4 36.7 Gbytes (formatted, rounded off value) Read/write data heads 8 4 2 Bytes per track 471,916 471,916 471,916 Bytes (average, rounded off values) Bytes per surface 18,351 18,351 18,351 Mbytes (unformatted, rounded off value) Tracks per surface (total) 50,864 50,864 50,864 Tracks (user accessible) Tracks per inch 85,000 85,000 85,000 TPI Peak bits per inch 628 628 628 KBPI Internal data rate 685-1 , 14 2 685-1,142 685-1,142 Mbits/sec (variable with zone) Disc rotation speed 15k 15k 15k rpm Avg rotational latency 2.0 2.0 2.0 msec

4.2 Seek performance characteristics

See Section 9.5 , " FC- AL ph ys i cal inte r fac e" on page 64 and the Fibre Cha nnel Inte rface Manual (part num ber

77767496) for additional timing details.

4.2.1 Access time

Not including controller overhead Read Write

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.

1,2

(msec)

Cheetah 15K.4 FC Product Manual, Rev. C 11

4.2.2 Format command execution time (minutes)

ST3146854FC ST373454FC ST336754FC

Maximum (with verify) Maximum (without veri fy )

90 60 30 45 30 15

4.2.3 General performance characteristics

Data buffer to/from disc media (one 512-byte logical block)*

Minimum 685 Mbits/sec Maximum 1,142 Mbits/sec

Fibre Channel Interface maximum instantaneous transfer rate 20 0 Mby tes /s ec * per port

Logical block sizes

Default is 512-byte data blocks Variable 512 to 704 byt es 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 per formance i mpac t (for flaws rea llocated a t format tim e using the spare sectors per sparing zone reallocation scheme.)

Average rotation al lat enc y 2.0 msec

*Assumes no errors and no relocated logical blocks. Rate measured from the start of the first logical block transfer to or from the host.

(dual port = 400 Mbytes/sec*)

Negligible

4.3 Start/stop time

If the Motor Start option is disabled, the drive becomes ready within 20 seconds after DC power is applied. If a recoverable error condition is detected during the start sequence, the drive executes a recovery procedure and the time to become ready may ex ceed 20 s econds. Stop time is 3 0 seconds ( maximum) from removal of DC power.

If the Motor Start option is enabled, the internal controller accep ts the commands listed in the Fibre Channel Interface Manual less than 3 sec onds after DC power has been appli ed. After the Motor Start command has been received, the drive becomes ready for normal operations within 20 seconds (excluding the error recovery procedure). The Motor Start command can also be used to command the drive to stop the spindle.

There is no power control switch on the drive.

4.4 Prefetch/multi-segmented cache control

The drive provides a prefetch ( read look-ahead) and multi-se gmented cache control algori thms that in many cases can enhan ce system performance. Cac he refers to the drive buffer stor age space when it is used in cache operations . To select this feature, the host sends the Mode Select com mand with the proper va lues in

12 Cheetah 15K.4 FC Product Manual, Rev. C

the applicable bytes in page 08h. Prefetch and cache operations are independent features from the standpoint that each is enabled and dis abled indepe ndently using the Mode Select c ommand; however, in actual opera tion, the prefetch feature overlaps cache operation somewhat as described in sections 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

16.

4.5 Cache operation

Note. Refer to the Fibre Channel Interface Manual for more detail concerning the cache bits.

Of the 8,192 kbytes p hysical buffer space in the drive , approximately 7,077 k bytes can be used as a cache. The buffer can be divided into logical segments (using Mode Select Page 08h, byte 13) from which data is read and to which data is written.

The drive keeps track of the logical block addresses of the data stor ed in each segment of the buffer. If the cache is enabled (see RCD bit in the Fibre Chann el In ter fac e M anua l command is retrieved from the buffer, if possible, before any disc access is initiated. If cac he operation is not enabled, the buffer (still segm ented with the required number of s egments) is still used, but only as ci rcular buffer segments during disc medium read operations (disreg arding Prefetch operatio n 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 through some buffer segment on the way to the hos t. On a cache miss, all data transfers to the host are in accordance with buffer-full ratio rules. On a cache hit, the drive ignores the buffer-full ratio rules. See the explanation provided with the information about Mode Page 02h (dis connect/reconnect control) in the Fibre Channel Interface Manual.

), data requested by the host wi th a rea d

The following is a simplified description of the prefetch/cache operation: Case A—read command is received and the first logical block is already in the cache:

1. Drive transfers to the initiator the first logical block requested plus all subsequent contiguous logical blocks

that are already in the cache. This data may be in multiple segments.

2. When a requested logical block i s reached that is not in an y cache se gment, the dri ve fetches it and any

remaining requested lo gical b lock a ddres ses from th e disc and puts them in a seg ment o f the cache . The drive transfers the r emaining requested logical blocks from t he cache to the host in a ccordance with the Mode Select Disconnect/Reconnect parameters, page 02h.

3. If the prefetch feature is enabled, refer to section 4.5.2 for operation from this point. Case B—A Read command requests data, and the first logical block is not in any segment of the cache:

1. The drive fetches the requested lo gical bl ocks from t he disc and transfe rs them int o a segme nt, and then

from there to the host in accordance with the Mode Select Disconnect/Reconnect parameters, page 02h.

2. If the prefetch feature is enabled, refer to section 4.5.2 for operation from this point. During a prefetch, the drive cross es a cylinder boundary to fetc h data only if the Disco ntinui ty (DISC) bit is se t

to 1 in bit 4 of byte 2 of the Mode Select parameters page 08h. Default is zero for bit 4. Each cache se gment is actually a s elf-contained circula r buffer whose length is an integer number of logical

blocks. The wrap-ar ound capability of the individual segm ents greatly enhances the cache’s ove rall perfor mance, allowing a wide range of user-sele ctable configurations. The d rive supports operation of any integer number of segments from 1 to 32. Div ide the 7,077 Kbyte s in the b uffer by the numbe r of seg ments to get th e segment size in bytes; then divide by the sector size to get the number of sectors per segment, any partial sec tors remaining are not used. Default is 3 segments.

Note. The size of each segment is not reported by Mode Sense c ommand page 08h, bytes 14 and 15 .

The value 0XFFFF is always reported regardless of t he a ctu al size of th e segm ent . Se ndi ng a si ze specification using the Mode Select command (byt es 14 and 15) does not set up a new segment

Cheetah 15K.4 FC Product Manual, Rev. C 13

size. If the STRICT bit in Mode page 00h (byte 2, bit 1) is set to one , the driv e respon ds as it does for any attempt to change an unchangeable parameter.

4.5.1 Caching write data

Write caching is a write operation by the drive th at mak es use of a drive buffer sto ra ge area where the data to be written to the medium is stored 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 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 logical blocks exceed the size of the segment being written into, when the end of the segment is reached, the data is written into the beginning of the same cache segment, overwriting the data that was written there at the beginning of the operation; however, the drive does not overwrite data that has not yet been written to the medium.

If write caching is enabled (WCE=1), then the drive may return Good status on a write command after the data has been transferred into the cache, but befor e the data has been written to the medium. If an error oc curs while writing the data to the medium, and Good status has already been returned, a deferred error will be gen erated.

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.

Table 16 shows the mode default settings for the drive.

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 ch was requested by a Read c ommand are retrieved and stored in the buffer for immediate 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.

To enable Prefetch, use Mode Select page 08h , byte 12, bit 5 (Disable Read Ahead - DRA bit). DRA bit = 0 enables prefetch.

Since data that is pr efetch ed r eplaces data alr eady in som e b uffer segmen ts, the ho st can limit the a mount o f prefetch data to optimize system per formance. The Max Prefetch field (bytes 8 and 9) limits the amount of prefetch. The drive does not use the Prefetch Ceiling field (bytes 10 and 11).

During a prefetch operation, the drive cros ses a cylinder boundary to fetch more data only if Mode param ete rs page 08h, byte 2, bit 4 is set to 1 (Discontinuity--DISC bit).

When prefetch (read look -ahead) is enabled (enabled by DRA = 0), it opera tes under the control of ARLA (Adaptive Read Look-Ahead). If the host uses software interleave, ARLA enables prefetch of contiguous blocks from the disc when it senses that a prefetch hit will likely occur, even if two consecutive read operations were not for physically co ntiguous blocks of data (e.g. “software interleave ”). ARLA disables pref etch 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 ontiguous bloc ks of data , ARLA d isables pr efetc h, but as long as seq uentia l read operations request contiguous blocks of data, ARLA keeps prefetch enabled.

14 Cheetah 15K.4 FC Product Manual, Rev. C

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. For additio nal information about the PM bit , refer to the Unit Attention Parame ters page (00h) of the Mode Sense command (1Ah) in the Fibre Channel Interface Product Manual, part number 77767496.

Cheetah 15K.4 FC Product Manual, Rev. C 15

16 Cheetah 15K.4 FC Product Manual, Rev. C

5.0 Reliability specifications

The following reli ability specifica tions assume co rrect host and drive operational interfa ce, including al l interface timings, power supply voltages, environmental requirements and drive mounting constraints.

Seek error rate: Read Error Rates

Recovered Data Unrecovered Data Miscorrected Data

Interface error rate:

MTBF: 1,400,000 hours Preventive maintenance: None required

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 manual assume the following:

• The drive is operated in accordance with this manual u sing DC power as defined in paragraph 6.2, " DC

power requirements."

• 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.

Less than 10 errors in 108 seeks

Less than 10 errors in 1012 bits transferred (OEM default settings) Less than 1 sector in 1015 bits transferred Less than 1 sector in 1021 bits transferred Less than 1 error in 1012 bits transferred with minimum receive eye.

Less than 1 error in 1014 bits transferred with typical receive eye. See Section 9.6.4, "Differential PECL input." on page 72

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 FC Product Manual, Rev. C 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 addressed t rack . After 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. Recoverable seek erro rs are sp ecified at Le ss than 10 erro rs in 10

seeks. Unrecoverable seek errors

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

5.1.4 Interface errors

An interface error is defin ed as a failure of the receiver on a port to recover the d ata as transmitted by the device port connected to the receiver. The error may be detected as a running disparity error, illegal code, loss of word sync, or CRC error. The total error rate for a loop of de vices is the su m of the individual device error rates.

5.2 Reliability and service

Y ou can enhance the reliability of Cheetah K15.4 disc drives by ensuring that the drive receives adequate cooling. Section 6.0 provides temperature measure ments and other informa tion that m ay be used to enhanc e the service life of the drive. Section 8.3 provides recommended air-flow information.

5.2.1 Mean time between failure (MTBF)

The production disc drive achieves an MTBF of 1,400,000 hours when operated in an environment that ensures the case temperatu res specified in Section specification limi ts of the operati ng en vi r onm ent wi ll not affect MTBF perfo rm anc e. Oper a tin g the dr iv e at c ase temperatures above these values will adversely affect the drive’s ability to meet specifications (see "Environmental limits" ).

6.4.1 are not ex ceeded. Short-term excursions up to the Section 6.4,

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

MTBF per measurement period = Estimated power-on operating hours in the p eriod

Number of drive failures in the period

Estimated power-on operating hours means power-on hours per disc drive times the total number of disc drives in service. Each dis c driv e mu st hav e accu mul ate d at lea st ni ne mon ths of operati on . Data is calculate d 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

• Operating at nominal voltages

• System provides adequate cooling to ensure the case temperatures specified in Section 6.4.1 are not exceeded.

Drive failure means any stoppage or failure to meet defined specifications caused by drive malfunction. A S.M.A.R.T. predictive failure indic ates that the drive i s deterior ating to an immin ent failu re and is co nside red

an MTBF hit.

5.2.2 Preventive maintenance

No routine scheduled preventive maintenance is required.

18 Cheetah 15K.4 FC Product Manual, Rev. C

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