seagate ST336752FC, ST318452FC Product Manual

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Cheetah X15 36LP FC Disc Drive

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ST336752FC

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ST318452FC

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Product Manual, Volume 1

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Cheetah X15 36LP FC Disc Drive

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ST336752FC

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ST318452FC

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Product Manual, Volume 1

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© 2001 Seagate Technology LLC. All rights reserved
October 2001

Publication number: 100139874, Rev. B

Seagate, Seagate Technology, and the Seagate logo are registered trademarks of Seagate Technology LLC.
Cheetah, SeaFAX, SeaFONE, SeaBOARD, and SeaTDD are either registered trademarks or trademarks of
Seagate Technology LLC. Other product names are registered trademarks or trademarks of their owners.

Seagate reserves the right to change, without notice, product offerings or specifications. No part of this publica-

tion may be reproduced in any form without written permission of Seagate Technology LLC.

Printed in the United States of America.

Revision status summary sheet

Revision Date Writer/Engineer Sheets Affected

A 06/27/2001 L. Newman/J. Nowitzke All.
B 10/30/2001 L. Newman/B. Hohn Page 22.

Cheetah X15 36LP FC Product Manual, Rev. B v

Contents

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

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

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

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

2.1.2 Electromagnetic compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.2 Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

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

3.1 Standard features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3.2 Media description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3.3 Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3.4 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.5 Unformatted and formatted capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.6 Programmable drive capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.7 Factory-installed accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.8 Factory-installed options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.9 User-installed accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

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

4.1 Internal drive characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.2 Seek performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

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

4.2.2 Format command execution time for ≥ 512-byte sectors . . . . . . . . . . . . . . . . . . . . . 9

4.2.3 General performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

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

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

4.5 Cache operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

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

4.5.2 Prefetch operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.5.3 Optimizing cache performance for desktop and server applications . . . . . . . . . . . 12

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

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

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

5.1.2 Write errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.1.3 Seek errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

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

5.2.1 Mean time between failure (MTBF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2.2 Preventive maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2.3 Service life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2.4 Service philosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2.5 Service tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2.6 Hot plugging the drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.2.7 S.M.A.R.T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.2.8 Thermal Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

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

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

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

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

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

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

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

6.2.3 Current profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6.3 Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.4 Environmental limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

6.4.1 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

vi Cheetah X15 36LP FC Product Manual, Rev. B

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

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

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

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

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

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

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

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

7.1 Drive internal defects/errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

7.2 Drive error recovery procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

7.3 FC-AL system errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

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

8.1 Drive ID/option selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

8.2 LED connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

8.2.1 J6 connector requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

8.3 Drive orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

8.4 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

8.5 Drive mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

8.6 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

9.0 Interface requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

9.1 FC-AL features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

9.1.1 Fibre Channel link service frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

9.1.2 Fibre Channel task management functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

9.1.3 Fibre Channel task management responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

9.1.4 Fibre Channel port login. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

9.1.5 Fibre Channel port login accept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

9.1.6 Fibre Channel Process Login. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

9.1.7 Fibre Channel Process Login Accept. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

9.1.8 Fibre Channel fabric login . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

9.1.9 Fibre Channel fabric accept login . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

9.1.10 Fibre Channel Arbitrated Loop options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

9.2 Dual port support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

9.3 SCSI commands supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43

9.3.1 Inquiry data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

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

9.4 Miscellaneous operating features and conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

9.5 FC-AL physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

9.5.1 Physical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

9.5.2 Connector requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

9.5.3 Electrical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

9.5.4 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

9.5.5 FC-AL transmitters and receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

9.5.6 Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

9.5.7 Fault LED Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

9.5.8 Active LED Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

9.5.9 Enable port bypass signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

9.5.10 Motor start controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

9.5.11 SEL_6 through SEL_0 ID lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

9.5.12 Device control codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

9.6 Signal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

9.6.1 TTL input characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

9.6.2 LED driver signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

9.6.3 Differential PECL output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

9.6.4 Differential PECL input. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

10.0 Seagate Technology support services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

Cheetah X15 36LP FC Product Manual, Rev. B vii

List of Figures

Figure 1. Cheetah X15 36LP FC family disc drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2. Cheetah X15 36LP FC disc drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 3. Typical ST336752FC drive +12V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 4. Typical ST336752FC drive +5V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 5. Typical ST318452FC drive +12V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 6. Typical ST318452FC drive +5V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 7. ST336752FC DC current and power vs. input/output operations per second . . . . . . . . . . . . 25

Figure 8. ST318452FC DC current and power vs. input/output operations per second . . . . . . . . . . . . 25

Figure 9. Locations of the HDA temperature check point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 10. Recommended mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 11. Mounting configuration dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 12. Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 13. LED indicator connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 14. Air flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 15. Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Figure 16. Port bypass circuit physical interconnect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Figure 17. FC-AL SCA device connector dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Figure 18. J6 connector dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Figure 19. FC-AL transmitters and receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Figure 20. Transmit eye diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Figure 21. Receive eye diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Cheetah X15 36LP FC Product Manual, Rev. B 1

1.0 Scope

This manual describes Seagate Technology® LLC, Cheetah X15 36LP FC (Fibre Channel) disc drives.

Cheetah X15 36LP FC drives support the Fibre Channel Arbitrated Loop and SCSI Fibre Channel Protocol
specifications to the extent described in this manual. The

77767496) describes the general Fibre Channel Arbitrated Loop characteristics of this and other Seagate Fibre
Channel drives.

Figure 1. Cheetah X15 36LP FC family disc drive

Fibre Channel Interface Manual

(part number

2 Cheetah X15 36LP FC Product Manual, Rev. B

Cheetah X15 36LP FC Product Manual, Rev. B 3

2.0 Applicable standards and reference documentation

The drive has been developed as a system peripheral to the highest standards of design and construction. The
drive depends upon its host equipment to provide adequate power and environment in order to achieve opti­mum performance and compliance with applicable industry and governmental regulations. Special attention
must be given in the areas of safety, power distribution, shielding, audible noise control, and temperature regu­lation. In particular, the drive must be securely mounted in order to guarantee the specified performance char­acteristics. Mounting by bottom holes must meet the requirements of Section 8.5.

2.1 Standards

The Cheetah X15 36LP FC family complies with Seagate standards as noted in the appropriate sections of this
manual and the Seagate

The Cheetah X15 36LP 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 integration and installation into a suitable enclosure prior to use.
As such the drive is supplied as a subassembly and is not subject to Subpart B of Part 15 of the FCC Rules
and Regulations nor the Radio Interference Regulations of the Canadian Department of Communications.

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

Fibre Channel Interface Manual

, part number 77767496.

2.1.1.1 Electromagnetic susceptibility

As a component assembly, the drive is not required to meet any susceptibility performance requirements. It is
the responsibility of those integrating the drive within their systems to perform those tests required and design
their system to ensure that equipment operating in the same system as the drive or external to the system
does not adversely affect the performance of the drive. See Section 5.1.1 and Table 2, DC power requirements.

2.1.2 Electromagnetic compliance

Seagate uses an independent laboratory to confirm compliance with the directives/standards for CE Marking
and C-Tick Marking. The drive was tested in a representative system for typical applications. The selected sys­tem represents the most popular characteristics for test platforms. The system configurations include:

• 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 complies with the European Union requirements of the Electromagnetic
Compatibility Directive 89/336/EEC of 03 May 1989 as amended by Directive 92/31/EEC of 28 April 1992 and
Directive 93/68/EEC of 22 July 1993.

4 Cheetah X15 36LP FC Product Manual, Rev. B

Australian C-Tick

If this model has the C-Tick Marking it complies with the Australia/New Zealand Standard AS/NZS3548 1995
and meets the Electromagnetic Compatibility (EMC) Framework requirements of Australia’s Spectrum Man­agement 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 Electromagnetic
Compatibility Framework requirements of the Radio Research Laboratory (RRL) Ministry of Information and
Communication Republic of Korea.

Taiwanese BSMI

If this model has two Chinese words meaning “EMC certification” followed by an eight digit identification num­ber, as a Marking, it complies with Chinese National Standard (CNS) 13438 and meets the Electromagnetic
Compatibility (EMC) Framework requirements of the Taiwanese Bureau of Standards, Metrology, and Inspec­tion (BSMI).

2.2 Reference documents

Cheetah X15 36LP FC Installation Guide

Seagate part number: 100139876

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
30553-001 Specification for Acoustic Test Requirement and Procedures

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 X15 36LP FC Product Manual, Rev. B 5

3.0 General description

Cheetah X15 36LPTM FC drives combine giant magnetoresistive (GMR) heads, partial response/maximum
likelihood (PRML) read channel electronics, embedded servo technology, and a Fibre Channel interface to pro­vide high performance, high capacity data storage for a variety of systems including engineering workstations,
network servers, mainframes, and supercomputers. Cheetah X15 36LP 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 X15 36LP FC drives are random access storage devices designed to support the Fibre Channel Arbi­trated Loop (FC-AL) and SCSI Fibre Channel Protocol as described in the ANSI specifications, this document,
and the
acteristics of this drive. Cheetah X15 36LP FC drives are classified as intelligent peripherals and provide level
2 conformance (highest level) with the ANSI SCSI-1 standard.

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

See Figure 2 for an exploded view of the drive. Never disassemble the HDA. This exploded view is for informa­tion only. Do not attempt to service items in the sealed enclosure (heads, media, actuator, etc.) as this requires
special facilities. The drive contains no parts replaceable by the user and opening the HDA for any reason
voids your warranty.

Fibre Channel Interface Manual

(part number 77767496) which describes the general interface char-

Figure 2. Cheetah X15 36LP FC disc drive

Cheetah X15 36LP FC drives use a dedicated landing zone at the innermost radius of the media to eliminate
the possibility of destroying or degrading data by landing in the data zone. The heads automatically go to the
landing zone when power is removed from the drive.

An automatic shipping lock prevents potential damage to the heads and discs that results from movement dur­ing shipping and handling. The shipping lock disengages and the head load process begins when power is
applied to the drive.

Cheetah X15 36LP FC drives decode track 0 location data from the servo data embedded on each surface to
eliminate mechanical transducer adjustments and related reliability concerns.

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.

6 Cheetah X15 36LP FC Product Manual, Rev. B

3.1 Standard features

Cheetah X15 36LP FC drives have the following standard features:

• 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-selectable logical block size (512 to 704 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 aluminum substrate coated with a thin film magnetic material, overcoated
with a proprietary protective layer for improved durability and environmental protection.

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

• Adaptive seek velocity; improved seek performance

Cheetah X15 36LP FC Product Manual, Rev. B 7

3.4 Reliability

• 1,200,000 hour MTBF

• LSI circuitry

• Balanced low mass rotary voice coil actuator

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

• Dithering

3.5 Unformatted and formatted capacities

Formatted capacity depends on the spare reallocation sectors scheme selected, the number of data tracks per
sparing zone, and the number of alternate sectors (LBAs) per sparing zone. The following table shows the
standard OEM model capacity:

Formatted Unformatted

ST336752FC 0445DCC9h (36.7) Gbytes 47.5 Gbytes
ST318452FC 0222EE56h (18.4) Gbytes 23.7 Gbytes

Standard OEM models are formatted to 512 bytes per block. You can order other capacities by requesting a dif­ferent sparing scheme and logical block size.

Note. For 2 gigabit operation sector sizes must be divisible by 8.

The sector size is selectable at format time. Users having the necessary equipment may modify the data block
size before issuing a format command and obtain different formatted capacities than those listed. Cheetah X15
36LP FC drives use a zone sparing scheme. The drive is divided into frequency zones with a variable number
of spares in each zone.

3.6 Programmable drive capacity

Using the Mode Select command, the drive can change its capacity to something less than maximum. See the
Mode Select (6) parameter list table in the

Fibre Channel Interface Manual

, part number 7767496. A value of
zero in the Number of Blocks field indicates that the drive will not change the capacity it is currently formatted
to have. A number other than zero and less than the maximum number of LBAs in the Number of Blocks field
changes the total drive capacity to the value in the Number of Blocks field. A value greater than the maximum
number of LBAs is rounded down to the maximum capacity.

3.7 Factory-installed accessories

OEM standard drives are shipped with the

Cheetah X15 36LP FC Installation Guide

(part number 100139876).

3.8 Factory-installed options

You may order the following items which are incorporated at the manufacturing facility 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 shipping pack. The drive is normally shipped in bulk packaging to provide maximum protection

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

• The

Cheetah X15 36LP FC Installation Guide,

part number 100139876, is usually included with each stan-

dard OEM drive shipped, but extra copies may be ordered.

• The

Safety and Regulatory Agency Specifications

, part number 75789512, is usually included with each

standard OEM drive shipped, but extra copies may be ordered.

3.9 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.

8 Cheetah X15 36LP FC Product Manual, Rev. B

Cheetah X15 36LP FC Product Manual, Rev. B 9

4.0 Performance characteristics

This section provides detailed information concerning performance-related characteristics and features of
Cheetah X15 36LP FC drives.

4.1 Internal drive characteristics

ST336752FC ST318452FC

Drive capacity 36.7 .......................... 18.4........... .......... Gbytes (formatted, rounded off value)

Read/write data heads 8 ............................... 4

Bytes per track 316,155 .................... 316,155..... .......... Bytes (average, rounded off values)

Bytes per surface 5,933 ........................ 5,933......... .......... Mbytes (unformatted, rounded off value)

Tracks per surface (total) 18,497 ...................... 18,497....... ..........Tracks (user accessible)

Tracks per inch 38,000 ...................... 38,000....... .......... TPI

Peak bits per inch 482 ........................... 482............ .......... KBPI

Internal data rate 548-706 .................... 548-706..... ..........Mbits/sec (variable with zone)

Disc rotation speed 15k............................ 15k............ .......... rpm

Avg rotational latency 2.0 ............................ 2.0............. .......... msec

4.2 Seek performance characteristics

See Section 9.5, "FC-AL physical interface" on page 52 and the

Fibre Channel Interface Manual

(part number

77767496) for additional timing details.

4.2.1 Access time

Including controller overhead
(msec)

Read Write Read Write

Average Typical
Single track Typical
Full stroke Typical

1. Execution time measured from receipt of the FCP Command to the FCP Response.

2. Assumes no errors and no sector has been relocated.

3. Typical access times are measured under nominal conditions of temperature, voltage, and horizontal orientation as

measured on a representative sample of drives.

4. Access time = controller overhead + average seek time.

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

3,4

3,4

3,4

3.8 4.4 3.6 4.2

0.5 0.6 0.3 0.4

7.28.27.08.0

1, 2

Not including controller overhead
(msec)

1,2

4.2.2 Format command execution time for ≥ 512-byte sectors

ST336752FC ST318452FC

Maximum (with verify) 90 minutes 60 minutes
Maximum (without verify) 45 minutes 30 minutes

10 Cheetah X15 36LP FC Product Manual, Rev. B

4.2.3 General performance characteristics

Minimum sector interleave 1 to 1

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

Minimum 51.8 MBytes/sec
Maximum 68.1 MBytes/sec

Fibre Channel Interface maximum instantaneous transfer rate 200 Mbytes/sec* per

port (dual port = 400
Mbytes/sec*)

Logical block sizes

Default is 512-byte data blocks
Variable 512 to 704 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

Flaw reallocation performance impact (for flaws reallocated at format time
using the spare sectors per sparing zone reallocation scheme.)

Overhead time for head switch in sequential mode

Overhead time for one track cylinder switch in sequential mode

Average rotational latency

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

Ye s

Negligible

0.8 msec

1.2 msec (typical)

2.0 msec

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 exceed 30 seconds. Stop time is 30 seconds (maximum) from removal of DC
power.

If the Motor Start option is enabled, the internal controller accepts the commands listed in the

Interface Manual

less than 3 seconds after DC power has been applied. After the Motor Start command has

Fibre Channel

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-segmented cache control algorithms that in many
cases can enhance system performance. Cache refers to the drive buffer storage space when it is used in
cache operations. To select this feature, the host sends the Mode Select command with the proper values in
the applicable bytes in page 08h. Prefetch and cache operations are independent features from the standpoint
that each is enabled and disabled independently using the Mode Select command; however, in actual opera­tion, the prefetch feature overlaps cache operation somewhat as described in sections 4.5.1 and 4.5.2.

All default cache and prefetch mode parameter values (Mode Page 08h) for standard OEM versions of this
drive family are given in Table 16.

Cheetah X15 36LP FC Product Manual, Rev. B 11

4.5 Cache operation

Note. Refer to the

Of the 8,192 kbytes physical buffer space in the drive, approximately 7,500 kbytes 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 stored in each segment of the buffer. If the
cache is enabled (see RCD bit in the
command is retrieved from the buffer, if possible, before any disc access is initiated. If cache operation is not
enabled, the buffer (still segmented with the required number of segments) is still used, but only as circular
buffer segments during disc medium read operations (disregarding Prefetch operation for the moment). That is,
the drive does not check in the buffer segments for the requested read data, but goes directly to the medium to
retrieve it. The retrieved data merely passes through some buffer segment on the way to the host. On a cache
miss, all data transfers to the host are in accordance with buffer-full ratio rules. On a cache hit, the drive ignores
the buffer-full ratio rules. See the explanation provided with the information about Mode Page 02h (disconnect/
reconnect control) in the

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 is reached that is not in any cache segment, the drive fetches it and any

remaining requested logical block addresses from the disc and puts them in a segment of the cache. The
drive transfers the remaining requested logical blocks from the cache to the host in accordance 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.

Fibre Channel Interface Manual

Fibre Channel Interface Manual

Fibre Channel Interface Manual

for more detail concerning the cache bits.

), data requested by the host with a read

.

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 logical blocks from the disc and transfers them into a segment, 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 crosses a cylinder boundary to fetch data only if the Discontinuity (DISC) bit is set
to 1 in bit 4 of byte 2 of the Mode Select parameters page 08h. Default is zero for bit 4.

Each cache segment is actually a self-contained circular buffer whose length is an integer number of logical
blocks. The wrap-around capability of the individual segments greatly enhances the cache’s overall perfor­mance, allowing a wide range of user-selectable configurations. The drive supports operation of any integer
number of segments from 1 to 16. Divide the 7,500 Kbytes in the buffer by the number of segments to get the
segment size. Default is 3 segments.

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

value 0XFFFF is always reported regardless of the actual size of the segment. Sending a size specifi­cation using the Mode Select command (bytes 14 and 15) does not set up a new segment size. 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 an unchangeable parameter.

4.5.1 Caching write data

Write caching is a write operation by the drive that makes use of a drive buffer storage area where the data to
be written to the medium is stored 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 same buffer space and segmentation is used as set up for read functions.
The buffer segmentation scheme is set up or changed independently, having nothing to do with the state of
RCD. When a write command is issued, if RCD=0, the cache is first checked to see if any logical blocks that
are to be written are already stored in the cache from a previous read or write command. If there are, the
respective cache segments are cleared. The new data is cached for subsequent Read commands.

12 Cheetah X15 36LP FC Product Manual, Rev. B

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 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.

Table 16 shows the mode default settings for the drive.

4.5.2 Prefetch operation

If the Prefetch feature is enabled, data in contiguous logical blocks on the disc immediately beyond that which
was requested by a Read command are retrieved and stored in the buffer for immediate transfer from the buffer
to the host on subsequent Read commands that request those logical blocks (this is true even if cache opera­tion is disabled). Though the prefetch operation uses the buffer as a cache, finding the requested data in the
buffer is a 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 prefetched replaces data already in some buffer segments, the host can limit the amount of
prefetch data to optimize system performance. The Max Prefetch field (bytes 8 and 9) limits the amount of
prefetch. The drive does not use the Prefetch Ceiling field (bytes 10 and 11).

During a prefetch operation, the drive crosses a cylinder boundary to fetch more data only if Mode parameters
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 operates under the control of ARLA
(Adaptive Read Look-Ahead). If the host uses software interleave, ARLA enables prefetch of contiguous blocks
from the disc when it senses that a prefetch hit will likely occur, even if two consecutive read operations were
not for physically contiguous blocks of data (e.g. “software interleave”). ARLA disables prefetch 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 not for contiguous blocks of data, ARLA disables prefetch, but as long as sequential read oper­ations request contiguous blocks of data, ARLA keeps prefetch enabled.

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 configure the cache to respond quickly to repetitive accesses of multiple small segments of data
without taking the time to “look ahead” to the next contiguous segments of data. In a server environment, you
want to configure the cache to provide large volumes of sequential data in a non-repetitive manner. In this
case, the ability of the cache to “look ahead” to the next contiguous segments of sequential data is a good
thing.

The Performance Mode (PM) bit controls the way the drive switches the cache buffer into different modes of
segmentation. In “server mode” (PM bit = 0), the drive can dynamically change the number of cache buffer seg­ments as needed to optimize the performance, based on the command stream from the host. 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 Parameters page (00h) of the Mode Sense command (1Ah) in the

Product Manual

, part number 77767496.

Fibre Channel Interface

Cheetah X15 36LP FC Product Manual, Rev. B 13

5.0 Reliability specifications

The following reliability specifications assume correct host and drive operational interface, including all 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:

1

Less than 10 errors in 10

Less than 10 errors in 10

Less than 1 sector in 10

Less than 1 sector in 10

Less than 1 error in 10
Less than 1 error in 10

See Section 9.6.4, "Differential PECL input." on page 60
MTBF: 1,200,000 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 using DC power as defined in paragraph 6.2, "DC
power requirements."

• The drive has been formatted with the FC-AL Format command.

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

• Assume random data.

8

seeks

12

bits transferred (OEM default settings)

15

bits transferred

21

bits transferred

12

bits transferred with minimum receive eye.

14

bits transferred with typical receive eye.

5.1.0.1 Interface errors

An interface error is defined as a failure of the receiver on a port to recover the data 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 devices is the sum of the individual device error
rates.

5.1.1 Environmental interference

When evaluating systems operation under conditions of electromagnetic interference (EMI), the performance
of the drive within the system is considered acceptable if the drive does not generate an unrecoverable condi­tion.

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

• is not detected and corrected by the drive itself

• is not detected from the error or fault status provided through the drive or FC-AL interface

• is not recovered by normal drive or system recovery procedures without operator intervention

5.1.2 Write errors

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

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

5.1.3 Seek errors

A seek error is defined as a failure of the drive to position the heads to the addressed track. After detecting an
initial seek error, the drive automatically performs an error recovery process. If the error recovery process fails,
a seek positioning error (15h) is reported with a Medium error (3h) or Hardware error (4h) reported in the
Sense Key. This is an unrecoverable seek error. Unrecoverable seek errors are classified as failures for MTBF

14 Cheetah X15 36LP FC Product Manual, Rev. B

calculations. Refer to the

Fibre Channel Interface Manual

, part number 77767496, for Request Sense informa-

tion.

5.2 Reliability and service

You can enhance the reliability of Cheetah X15 36LP FC disc drives by ensuring that the drive receives ade­quate cooling. Section 6.0 provides recommended air-flow information, temperature measurements, and other
information, which you can use to enhance the service life of the drive.

5.2.1 Mean time between failure (MTBF)

The production disc drive achieves an MTBF of 1,200,000 hours when operated in an environment that
ensures the case temperatures specified in Section 6.4.1 are not exceeded. Short-term excursions up to the
specification limits of the operating environment will not affect MTBF performance. Operating the drive at case
temperatures above these values will adversely affect the drive’s ability to meet specifications. See Section 6.4,
"Environmental limits".

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 period

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 disc drive must have accumulated at least nine months of operation. Data is calculated 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 indicates that the drive is deteriorating to an imminent failure and is considered
an MTBF hit.

5.2.2 Preventive maintenance

No routine scheduled preventive maintenance is required.

5.2.3 Service life

Depot repair or replacement of major parts is permitted during the service lifetime.

5.2.4 Service philosophy

Special equipment is required to repair the drive HDA. Repairs must be performed only at a properly equipped
and staffed Seagate service and repair facility. Troubleshooting and repair of PCBs in the field is not recom­mended because of the extensive diagnostic equipment required for effective servicing. There are not spare
parts available for this drive. The drive warranty is voided if the HDA is opened.

5.2.5 Service tools

No special tools are required for site installation or recommended for site maintenance. Refer to Section 5.2.4.
The depot repair philosophy of the drive precludes the necessity for special tools. Field repair of the drive is not
practical because users cannot purchase individual parts for the drive.

Cheetah X15 36LP FC Product Manual, Rev. B 15

5.2.6 Hot plugging the drive

Inserting and removing the drive on the FC-AL will interrupt loop operation. The interruption occurs when the
receiver of the next device in the loop must synchronize to a different input signal. FC error detection mecha­nisms, character sync, running disparity, word sync, and CRC are able to detect any error. Recovery is initiated
based on the type of error.

The disc drive defaults to the FC-AL Monitoring state, Pass-through state, when it is powered-on by switching
the power or hot plugged. The control line to an optional port bypass circuit (external to the drive), defaults to
the Enable Bypass state. If the bypass circuit is present, the next device in the loop will continue to receive the
output of the previous device to the newly inserted device. If the bypass circuit is not present, loop operation is
temporarily disrupted until the next device starts receiving the output from the newly inserted device and
regains synchronization to the new input.

The Pass-through state is disabled while the drive performs self test of the FC interface. The control line for an
external port bypass circuit remains in the Enable Bypass state while self test is running. If the bypass circuit is
present, loop operation may continue. If the bypass circuit is not present, loop operation will be halted while the
self test of the FC interface runs.

When the self test completes successfully, the control line to the bypass circuit is disabled and the drive enters
the FC-AL Initializing state. The receiver on the next device in the loop must synchronize to output of the newly
inserted drive.

If the self-test fails, the control line to the bypass circuit remains in the Enable Bypass state.

Note. It is the responsibility of the systems integrator to assure that no temperature, energy, voltage hazard,

or ESD potential hazard is presented during the hot connect/disconnect operation. Discharge the static
electricity from the drive carrier prior to inserting it into the system.

Caution. The drive motor must come to a complete stop prior to changing the plane of operation. This time is

required to insure data integrity.

5.2.7 S.M.A.R.T.

S.M.A.R.T. is an acronym for Self-Monitoring Analysis and Reporting Technology. This technology is intended
to recognize conditions that indicate imminent drive failure and is designed to provide sufficient warning of a
failure to allow you to back up the data before an actual failure occurs.

Note. The drive’s firmware monitors specific attributes for degradation over time but can’t predict instanta-

neous drive failures.

Each monitored attribute has been selected to monitor a specific set of failure conditions in the operating per­formance of the drive and the thresholds are optimized to minimize “false” and “failed” predictions.

Controlling S.M.A.R.T.

The operating mode of S.M.A.R.T. is controlled by the DEXCPT and PERF bits on the Informational Exceptions
Control mode page (1Ch). Use the DEXCPT bit to enable or disable the S.M.A.R.T. feature. Setting the DEX­CPT bit disables all S.M.A.R.T. functions. When enabled, S.M.A.R.T. collects on-line data as the drive performs
normal read and write operations. When the PERF bit is set, the drive is considered to be in “On-line Mode
Only” and will not perform off-line functions.

You can measure off-line attributes and force the drive to save the data by using the Rezero Unit command.
Forcing S.M.A.R.T. resets the timer so that the next scheduled interrupt is in two hours.

You can interrogate the drive through the host to determine the time remaining before the next scheduled mea­surement and data logging process occurs. To accomplish this, issue a Log Sense command to log page 0x3E.
This allows you to control when S.M.A.R.T. interruptions occur. Forcing S.M.A.R.T. with the RTZ command
resets the timer.

Performance impact

S.M.A.R.T. attribute data is saved to the disc so that the events that caused a predictive failure can be recre­ated. The drive measures and saves parameters once every two hours subject to an idle period on the FC-AL