Seagate ST318405LW-LC, ST39205LW-LC, ST336705LW-LC User Manual
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Cheetah 36XL Family:
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ST336705LW/LC
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ST318405LW/LC
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ST39205LW/LC
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Product Manual, Volume 1
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Cheetah 36XL Family:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ST336705LW/LC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ST318405LW/LC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ST39205LW/LC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product Manual, Volume 1
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© 2001 Seagate Technology LLC All rights reserved
Publication number: 75789517, Rev. E
October 2001
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.
Revision status summary sheet
Revision Date Writer/Engineer Sheets Affected
Rev. A 12/11/2000 K. Schweiss/B. Reynolds 1/1, v thru ix, 1-83.
Rev. B 02/27/2001 K. Schweiss/A. Steele 4.
Rev. C 05/24/2001 K. Schweiss/B. Reynolds 4, 51, 53, and 55.
Rev. D 07/30/2001 K. Schweiss/A. Steele 3 and 38.
Rev. E 10/09/2001 K. Schweiss/B. Reynolds 18, 40-42 ,49, 51-56, and 58.
Notice.
Product Manual 75789517 is Volume 1 of a two-volume document with the SCSI interface information in
the SCSI Interface Product Manual, Volume 2, part number 75789509.
If you need the SCSI interface information, order the SCSI Interface Product Manual, Volume 2, part
number 75789509.
Cheetah 36XL Product Manual, Rev. E v
Contents
1.0 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 Applicable standards and reference documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1 Electromagnetic compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.2 Electromagnetic susceptibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2 Electromagnetic compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3 Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.0 General description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Standard features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Media characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.4 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.5 Formatted capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.6 Programmable drive capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.7 Factory installed accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.8 Options (factory installed). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.0 Performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1 Internal drive characteristics (transparent to user) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2 SCSI performance characteristics (visible to user) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.1 Access time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.2 Format command execution time (minutes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.3 Generalized performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.3 Start/stop time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.4 Prefetch/multi-segmented cache control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.5 Cache operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1 Error rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1.1 Environmental interference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1.2 Read errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1.3 Write errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1.4 Seek errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2 Reliability and service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.1 Mean time between failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.2 Preventive maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.3 Service life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.4 Service philosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.5 Service tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.6 Hot plugging Cheetah 36XL disc drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2.7 S.M.A.R.T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2.8 Drive Self Test (DST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.2.8.1 DST Failure Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.2.8.2 Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.2.9 Product warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.0 Physical/electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.1 AC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.2 DC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.2.1 Conducted noise immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.2.2 Power sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.2.3 12 V - Current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6.3 Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
vi Cheetah 36XL Product Manual, Rev. E
6.4 Environmental limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
6.4.1 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
6.4.2 Relative humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
6.4.3 Effective altitude (sea level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
6.4.4 Shock and vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
6.4.4.1 Shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
6.4.4.2 Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
6.4.5 Air cleanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
6.4.6 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
6.4.7 Electromagnetic susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
6.5 Mechanical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
7.0 Defect and error management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
7.1 Drive internal defects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
7.2 Drive error recovery procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
7.3 SCSI systems errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
8.0 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
8.1 Drive ID/option select header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
8.1.1 Notes for figures 16, 17, and 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
8.1.2 Function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
8.2 Drive orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
8.3 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
8.4 Drive mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
8.5 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
9.0 Interface requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
9.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
9.2 SCSI interface messages supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
9.3 SCSI interface commands supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
9.3.1 Inquiry Vital Product data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
9.3.2 Mode Sense data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
9.4 SCSI bus conditions and miscellaneous features supported . . . . . . . . . . . . . . . . . . . . . . . . .57
9.5 Synchronous data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
9.5.1 Synchronous data transfer periods supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
9.5.2 REQ/ACK offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
9.6 Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
9.6.1 DC cable and connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
9.6.2 SCSI interface physical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
9.6.3 SCSI interface cable requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
9.6.4 Mating connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
9.6.4.1 Mating connectors for LW model drives . . . . . . . . . . . . . . . . . . . . . .61
9.6.4.2 Mating connectors for LC model drives . . . . . . . . . . . . . . . . . . . . . .61
9.7 Electrical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
9.7.1 Multimode—SE and LVD alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
9.7.1.1 Single-ended drivers/receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
9.7.1.2 Low voltage differential I/O circuits. . . . . . . . . . . . . . . . . . . . . . . . . .71
9.7.1.3 General cable characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
9.8 Terminator requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
9.9 Terminator power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
9.10 Disc drive SCSI timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
9.11 Drive activity remote LED signal status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
10.0 Seagate Technology support services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
Cheetah 36XL Product Manual, Rev. E vii
List of Figures
Figure 1. Cheetah 36XL family drive (ST336705LC shown) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Cheetah 36XL family drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 3. Typical ST336705 drive +12 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 4. Typical ST318405 drive +12 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 5. Typical ST39205 drive +12 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 6. Typical ST336705 drive +5 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 7. TypicalST318405 drive +5 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 8. TypicalST39205 drive +5 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 9. ST336705 DC current and power vs. input/output operations per second. . . . . . . . . . . . . . . 28
Figure 10. ST318405 DC current and power vs. input/output operations per second. . . . . . . . . . . . . . . 29
Figure 11. ST39205 DC current and power vs. input/output operations per second (LVD) . . . . . . . . . . 30
Figure 12. Location of HDA Temperature Check Point. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Figure 13. Recommended mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 14. LW mounting configuration dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 15. LC mounting configuration dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 16. J6 jumper header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Figure 17. J5 jumper header (on LW model only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 18. J2 option select header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure 19. LW model drive physical interface (68-pin J1 SCSI I/O connector) . . . . . . . . . . . . . . . . . . . . 59
Figure 20. LC model drive physical interface (80-pin J1 SCSI I/O connector) . . . . . . . . . . . . . . . . . . . . 59
Figure 21. SCSI daisy chain interface cabling for LW drives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Figure 22. Nonshielded 68 pin SCSI device connector used on LW drives . . . . . . . . . . . . . . . . . . . . . . 63
Figure 23. Nonshielded 80 pin SCSI “SCA-2” connector, used on LC drives . . . . . . . . . . . . . . . . . . . . . 64
Figure 24. LVD output signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Figure 25. Typical SE-LVD alternative transmitter receiver circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Cheetah 36XL Product Manual, Rev. E 1
1.0 Scope
This manual describes Seagate Technology® LLC Cheetah 36XL™ disc drives.
Cheetah 36XL drives support the Small Computer System Interface (SCSI) as described in the ANSI SCSI
interface specifications to the extent described in this manual. The
ber 75789509, describes general SCSI interface characteristics of this and other families of Seagate drives.
The
SCSI Interface Product Manual
From this point on in this product manual the reference to Cheetah 36XL models is referred to as “the drive”
unless references to individual models are necessary.
references information from the documents listed in Section 2.3.
SCSI Interface Product Manual,
part num-
Figure 1. Cheetah 36XL family drive (ST336705LC shown)
2 Cheetah 36XL Product Manual, Rev. E
Cheetah 36XL Product Manual, Rev. E 3
2.0 Applicable standards and reference documentation
The drive has been developed as a system peripheral to the highest standards of design and construction. The
drive depends upon 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 8.4.
2.1 Standards
The Cheetah 36XL family complies with Seagate standards as noted in the appropriate sections of this Manual
and the Seagate
The Cheetah 36XL disc drive is a UL recognized component per UL1950, CSA certified to CSA C22.2 No. 95095, 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.
SCSI Interface Product Manual
, part number 75789509.
2.1.2 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.
2.2 Electromagnetic compliance
Seagate uses an independent laboratory to confirm compliance to the directives/standard(s) for CE Marking
and C-Tick Marking. The drive was tested in a representative system for typical applications. The selected system represents the most popular characteristics for test platforms. The system configurations include:
• Typical current use microprocessor
• 3.5-inch floppy disc drive
• Keyboard
• Monitor/display
•Printer
• External modem
•Mouse
Although the test system with this Seagate model complies to the directives/standard(s), we cannot guarantee
that all systems will comply. The computer manufacturer or system integrator shall confirm EMC compliance
and provide CE Marking and C-Tick Marking for their product.
Electromagnetic compliance for the European Union
If this model has the CE Marking it 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 36XL Product Manual, Rev. E
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.
This drive has been tested and complies with the Electromagnetic Interference/Electromagnetic Susceptibility
(EMI/EMS) for Class B products.
• EUT name (model numbers): ST336705LC, ST336705LW, ST318405LW, ST318405LC, ST39205LC,
ST39205LW.
• Certificate number: E-H011-01-0340(B), E-H011-01-0341(B), E-H011-01-0347(B), E-H011-01-0344(B),
E-H011-01-0346(B), E-H011-01-0345(B) respectively.
• Trade name or applicant: Seagate Technology International
• Manufacturing start date: 01/2001
• Manufacturer/nationality: Singapore
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).
2.3 Reference documents
Cheetah 36XL Installation Guide
Safety and Regulatory Agency Specifications
SCSI Interface Product Manual
Applicable ANSI Small Computer System Interface (SCSI) document numbers:
T10/1143D Enhanced SCSI Parallel Interface (EPI)
T10/1236D Primary Commands-2 (SPC-2)
T10/996D SCSI Block Commands (SBC)
T10/1157D SCSI Architectural Model-2 (SAM-2)
T10/1302D SCSI Parallel Interface (SPI-3)
SFF-8046 Specification for 80-pin connector for SCSI disk drives
Package Test Specification Seagate P/N 30190-001 (under 100 lb.)
Package Test Specification Seagate P/N 30191-001 (over 100 lb.)
Seagate P/N 75789518
Seagate P/N 75789512
Seagate P/N 75789509
Specification, Acoustic Test Requirements, and Procedures Seagate P/N 30553-001
In case of conflict between this document and any referenced document, this document takes precedence.
Cheetah 36XL Product Manual, Rev. E 5
3.0 General description
Cheetah 36XL drives combine giant magnetoresistive (GMR) heads, partial response/maximum likelihood
(PRML) read channel electronics, embedded servo technology, and a wide SCSI Ultra160 interface to provide
high performance, high capacity data storage for a variety of systems including engineering workstations, network servers, mainframes, and supercomputers.
Ultra160 SCSI uses negotiated transfer rates. These transfer rates will occur only if your host adapter supports
these data transfer rates and is compatible with the required hardware requirements of the I/O circuit type. This
drive also operates at Ultra160 data transfer rates.
Table 1 lists the features that differentiate the Cheetah 36XL models.
Table 1: Drive model number vs. differentiating features
Number
Model number
of active
heads I/O circuit type [1]
Number of I/O
connector pins
Number of I/O
data bus bits
Data buffer
size (MB)
ST336705LW 8 Single-ended (SE) and low
68 16 4
voltage differential (LVD)
ST336705LC 8 Single-ended (SE) and low
80 16 4
voltage differential (LVD)
ST318405LW 4 Single-ended (SE) and low
68 16 4
voltage differential (LVD)
ST318405LC 4 Single-ended (SE) and low
80 16 4
voltage differential (LVD)
ST39205LW 2 Single-ended (SE) and low
68 16 4
voltage differential (LVD)
ST39205LC 2 Single-ended (SE) and low
80 16 4
voltage differential (LVD)
[1] See Section 9.6 for details and definitions.
The drive records and recovers data on approximately 3.0-inch (74 mm) non-removable discs.
The drive supports the Small Computer System Interface (SCSI) as described in the ANSI SCSI interface
specifications to the extent described in this manual (Volume 1), which defines the product performance characteristics of the Cheetah 36XL family of drives, and the
SCSI Interface Product Manual
, part number
75789509, which describes the general interface characteristics of this and other families of Seagate SCSI
drives.
The drive’s interface supports multiple initiators, disconnect/reconnect, and automatic features that relieve the
host from the necessity of knowing the physical characteristics of the targets (logical block addressing is used).
The head and disc assembly (HDA) is sealed at the factory. Air circulates within the HDA through a nonreplaceable filter to maintain a contamination-free HDA environment.
Refer to Figure 2 for an exploded view of the drive. This exploded view is for information only—never disassemble the HDA and do not attempt to service items in the sealed enclosure (heads, media, actuator, etc.) as this
requires special facilities. The drive contains no replaceable parts. Opening the HDA voids your warranty.
Cheetah 36XL 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 drive automatically goes to the landing
zone when power is removed.
6 Cheetah 36XL Product Manual, Rev. E
An automatic shipping lock prevents potential damage to the heads and discs that results from movement during shipping and handling. The shipping lock automatically disengages when power is applied to the drive and
the head load process begins.
Cheetah 36XL drives decode track 0 location data from the servo data embedded on each surface to eliminate
mechanical transducer adjustments and related reliability concerns.
A high-performance actuator assembly with a low-inertia, balanced, patented, straight-arm design provides
excellent performance with minimal power dissipation.
Figure 2. Cheetah 36XL family drive
Cheetah 36XL Product Manual, Rev. E 7
3.1 Standard features
The Cheetah 36XL family has the following standard features:
• Integrated Ultra160 SCSI controller
• Multimode SCSI drivers and receivers—single-ended (SE) and low voltage differential (LVD)
• 16 bit I/O data bus
• Asynchronous and synchronous data transfer protocol
• Firmware downloadable via SCSI interface
• Selectable even byte sector sizes from 512 to 4,096 bytes/sector
• Programmable sector reallocation scheme
• Flawed sector reallocation at format time
• Programmable auto write and read reallocation
• Reallocation of defects on command (post format)
• Enhanced ECC maximum burst correction length of 240 bits with a guaranteed burst correction length of 233
bits
• Sealed head and disc assembly
• No preventative maintenance or adjustment required
• Dedicated head landing zone
• Embedded servo design
• Self diagnostics performed when power is applied to the drive
• 1:1 Interleave
• Zoned bit recording (ZBR)
• Vertical, horizontal, or top down mounting
• Dynamic spindle brake
• 4,096 kbyte data buffer
• Hot plug compatibility (Section 9.6.4.2 lists proper host connector needed) for LC model drives
• Drive Self Test (DST)
3.2 Media characteristics
The media used on the drive has a diameter of approximately 3.0 inches (76.2 mm). The aluminum substrate is
coated with a thin film magnetic material, overcoated with a proprietary protective layer for improved durability
and environmental protection.
3.3 Performance
• Supports industry standard Ultra160 SCSI interface
• Programmable multi-segmentable cache buffer (see Section 3.1)
• 10,022 RPM spindle. Average latency = 2.99 ms
• Command queuing of up to 64 commands
• Background processing of queue
• Supports start and stop commands (spindle stops spinning)
3.4 Reliability
• 1,200,000 hour MTBF
• LSI circuitry
• Balanced low mass rotary voice coil actuator
• Incorporates industry-standard Self-Monitoring, Analysis and Reporting Technology (S.M.A.R.T.)
• 5-year warranty
8 Cheetah 36XL Product Manual, Rev. E
3.5 Formatted capacities
Formatted capacity depends on the number of spare reallocation sectors reserved and the number of bytes per
sector. The following table shows the standard OEM model read capacities data. Total LBAs = read capacity
data (shown below) +1.
Formatted
(data block size
512 bytes/sector) [1]
ST336705 445DCC9h (36.704 GB) [2]
ST318405 222EE55h (18.352 GB) [2]
ST39205 111772Ah (9.176 GB) [2]
Notes.
[1] Sector size 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. See
Mode Select command and Format command in the
SCSI Interface Product Manual
, part number
75789509.
[2] User available capacity depends on spare reallocation scheme selected, the number of data tracks per
sparing zone, and the number of alternate sectors (LBAs) per sparing zone.
3.6 Programmable drive capacity
Using the Mode Select command, the drive can change its capacity to something less than maximum. See the
Mode Select Parameter List table in the
SCSI Interface Product Manual
, part number 75789509. 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 change the capacity it is currently formatted to have. A number in the number of blocks
field that is less than the maximum number of LBAs changes the total drive capacity to the value in the block
descriptor 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
Safety and Regulatory Agency Specifications
Cheetah 36XL Installation Guide
, part number 75789518, and the
, part number 75789512, unless otherwise specified. The factory
also ships with the drive a small bag of jumper plugs used for the J2, J5, and J6 option select jumper headers.
3.8 Options (factory installed)
All customer requested options are incorporated during production or packaged at the manufacturing facility
before shipping. Some of the options available are (not an exhaustive list of possible options):
• The
Cheetah 36XL Installation Guide
, part number 75789518, is usually included with each standard 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.
Cheetah 36XL Product Manual, Rev. E 9
4.0 Performance characteristics
4.1 Internal drive characteristics (transparent to user)
ST336705 ST318405 ST39205
Drive capacity 36.704 18.352 9.176 GByte (formatted, rounded off values)
Read/write heads 8 4 2
Bytes/track 241,128 241,128 241,128 Bytes (average, rounded off values)
Bytes/surface 4,577.5 4,577.5 4,577.5 Mbytes (unformatted, rounded off values)
Tracks/surface (total) 19,036 19,036 19,036 Tracks (user accessible)
Tracks/inch 24,406 24,406 24,406 TPI
Peak bits/inch 381.28 381.28 381.28 KBPI
Internal data rate 320-490 320-490 320-490 Mbits/sec (variable with zone)
Disc rotational speed 10,022 10,022 10,022 r/min (+
Average rotational latency 2.99 2.99 2.99 msec
4.2 SCSI performance characteristics (visible to user)
The values given in Section 4.2.1 apply to all models of the Cheetah 36XL family unless otherwise specified.
Refer to Section 9.10 and to the
SCSI Interface Product Manual
, part number 75789509, for additional timing
details.
0.5%)
4.2.1 Access time [5]
Including controller overhead
(without disconnect) [1] [3]
Drive level Drive level
Not including controller overhead
(without disconnect) [1] [3]
Read Write Read Write
msec msec
Average—Typical [2] 5.6 6.4 5.4 6.2
Single Track—Typical [2] 1.0 1.4 0.8 1.2
Full Stroke—Typical [2] 10.7 11.2 10.5 11
4.2.2 Format command execution time (minutes) [1]
ST336705 ST318405 ST39205
Maximum (with verify) 36 18 9
Maximum (no verify) 19 9.5 4.5
4.2.3 Generalized performance characteristics
Minimum sector interleave 1 to 1
Data buffer transfer rate to/from disc media (one contiguous 512-byte sector):
Minimum [3] 31 MByte/sec
Average [3] 43 MByte/sec
Maximum [3] 50 MByte/sec
Data buffer transfer rate to/from disc media (<1 track)
Minimum [3] 29 MByte/sec
Average [3] 40 MByte/sec
Maximum [3] 46 MByte/sec
10 Cheetah 36XL Product Manual, Rev. E
SCSI interface data transfer rates (asynchronous):
Maximum instantaneous 8 bit wide 5.0 Mbytes/sec [4]
Maximum instantaneous 16 bit wide 10.0 Mbytes/sec [4]
Synchronous formatted transfer rates: Ultra2 SCSI Ultra160 SCSI
In SCSI Wide (16 bit) 10.0 to 80 Mbytes/sec 10.0 to 160 Mbytes/sec [6]
Sustainable data transfer rates:
Minimum 23 Mbytes/sec
Average 33 Mbytes/sec
Maximum 37 Mbytes/sec
Sector Sizes:
Default 512 byte user data blocks
Variable 512 to 4,096 bytes per sector in even number of bytes per sector.
If n (number of bytes per sector) is odd, then n-1 will be used.
Read/write consecutive sectors on a track Yes
Flaw reallocation performance impact (for flaws reallocated at format
time using the spare sectors per sparing zone reallocation scheme.)
Negligible
Average rotational latency 2.99 msec
Notes for Section 4.2.
[1] Execution time measured from receipt of the last byte of the Command Descriptor Block (CDB) to the
request for a Status Byte Transfer to the Initiator (excluding connect/disconnect).
[2] Typical access times are measured under nominal conditions of temperature, voltage, and horizontal ori-
entation as measured on a representative sample of drives.
[3] Assumes no errors and no sector has been relocated.
[4] Assumes system ability to support the rates listed and no cable loss.
[5] Access time = controller overhead + average seek time.
Access to data = controller overhead + average seek time + latency time.
[6] Drive required to be in LVD mode to attain maximum transfer rates.
4.3 Start/stop time
After DC power at nominal voltage has been applied, the drive becomes ready within 20 seconds if the Motor
Start Option is disabled (i.e. the motor starts as soon as the power has been applied). If a recoverable error
condition is detected during the start sequence, the drive executes a recovery procedure which may cause the
time to become ready to exceed 20 seconds. During spin up to ready time the drive responds to some commands over the SCSI interface in less than 3 seconds after application of power. Stop time is less than 15 seconds from removal of DC power.
If the Motor Start Option is enabled, the internal controller accepts the commands listed in the
Product Manual
been received the drive becomes ready for normal operations within 10 seconds typically (excluding an error
recovery procedure). The Motor Start Command can also be used to command the drive to stop the spindle
(see
SCSI Interface Product Manual
less than 3 seconds after DC power has been applied. After the Motor Start Command has
, part number 75789509).
SCSI Interface
There is no power control switch on the drive.
4.4 Prefetch/multi-segmented cache control
The drive provides prefetch (read look-ahead) and multi-segmented cache control algorithms that in many
cases can enhance system performance. “Cache” as used herein refers to the drive buffer storage space when
it is used in cache operations. To select prefetch and cache features the host sends the Mode Select command
with the proper values in the applicable bytes in Mode Page 08h (see
number 75789509). Prefetch and cache operation are independent features from the standpoint that each is
SCSI Interface Product Manual,
part
Cheetah 36XL Product Manual, Rev. E 11
enabled and disabled independently via the Mode Select command. However, in actual operation the prefetch
feature overlaps cache operation somewhat as is noted in Section 4.5.1 and 4.5.2.
All default cache and prefetch Mode parameter values (Mode Page 08h) for standard OEM versions of this
drive family are given in Tables 7 and 8.
4.5 Cache operation
In general, 4096 kbytes of the physical buffer space in the drive can be used as storage space for cache operations. The buffer can be divided into logical segments (Mode Select Page 08h, byte 13) from which data is
read and to which data is written. The drive maintains a table of logical block disk medium addresses of the
data stored in each segment of the buffer. If cache operation is enabled (RCD bit = 0 in Mode Page 08h, byte 2,
bit 0. See
command is retrieved from the buffer (if it is there), before any disc access is initiated. If cache operation is not
enabled, the buffer (still segmented with required number of segments) is still used, but only as circular buffer
segments during disc medium read operations (disregarding Prefetch operation for the moment). That is, the
drive does not check in the buffer segments for the requested read data, but goes directly to the medium to
retrieve 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 explanations associated with Mode page 02h (disconnect/reconnect control) in
the
SCSI Interface Product Manual
The following is a simplified description of a read operation with cache operation enabled:
SCSI Interface Product Manual,
.
part number 75789509), data requested by the host with a Read
Case A - A Read command is received and the first logical block (LB) is already in cache:
1. Drive transfers to the initiator the first LB requested plus all subsequent contiguous LBs that are already in
the cache. This data may be in multiple segments.
2. When the requested LB is reached that is not in any cache segment, the drive fetches it and any remaining
requested LBs from the disc and puts them in a segment of the cache. The drive transfers the remaining
requested LBs from the cache to the host in accordance with the disconnect/reconnect specification mentioned above.
3. If the prefetch feature is enabled, refer to Section 4.5.2 for operation from this point.
Case B - A Read command requests data, the first LB of which is not in any segment of the cache:
1. The drive fetches the requested LBs from the disc and transfers them into a segment, and from there to the
host in accordance with the disconnect/reconnect specification referred to in case A.
2. If the prefetch feature is enabled, refer to Section 4.5.2 for operation from this point.
Each buffer segment is actually a self-contained circular storage area (wrap-around occurs), the length of
which is an integer number of disc medium sectors. The wrap-around capability of the individual segments
greatly enhances the buffer’s overall performance as a cache storage, allowing a wide range of user selectable
configurations, which includes their use in the prefetch operation (if enabled), even when cache operation is
disabled (see Section 4.5.2). The number of segments may be selected using the Mode Select command, but
the size can not be directly selected. Size is selected only as a by-product of selecting the segment number
specification. The size in Kbytes of each segment is not reported by the Mode Sense command page 08h,
bytes 14 and 15. The value 0x0000 is always reported. If a size specification is sent by the host in a Mode
Select command (bytes 14 and 15) no new segment size is set up by the drive, and if the STRICT bit in Mode
page 00h (byte 2, bit 1) is set to one, the drive responds as it does for any attempt to change unchangeable
parameters (see
integer number of segments from 1 to 32. The default number of segments is defined in Tables 7 and 8.
SCSI Interface Product Manual,
part number 75789509). The drive supports operation of any
4.5.1 Caching write data
Write caching is a write operation by the drive that makes use of a drive buffer storage area where the data to
be written to the medium is stored in one or more segments while the drive performs the write command.
If read caching is enabled (RCD=0), 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
12 Cheetah 36XL Product Manual, Rev. E
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.
If the number of write data logical blocks exceeds 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.
Tables 7 and 8 show Mode default settings for the drives.
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 can be retrieved and stored in the buffer for immediate transfer from the
buffer to the host on subsequent Read commands that request those logical blocks (this is true even if cache
operation is disabled). Though the prefetch operation uses the buffer as a cache, finding the requested data in
the buffer is a prefetch hit, not a cache operation hit. Prefetch is enabled using Mode Select page 08h, byte 12,
bit 5 (Disable Read Ahead - DRA bit). DRA bit = 0 enables prefetch. Since data that is prefetched replaces data
already in some buffer segment(s), the host can limit the 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 the Discontinuity
(DISC) bit is set to one in bit 4 of byte 2 of Mode parameters page 08h.
Whenever prefetch (read look-ahead) is enabled (enabled by DRA = 0), it 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 increase the number of cache buffer segments
above the value defined in Mode Page 8, Byte 13, 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. For additional information about the PM bit, refer to the Unit
Attention Parameters page (00h) of the Mode Sense command (1Ah) in the
part number 75789509.
SCSI Interface Product Manual
,
Cheetah 36XL Product Manual, Rev. E 13
The base cache buffer configuration for desktop or server environments needs to be set correctly by the host
system. This involves setting the PM bit in Mode Page 0, Byte 2, as well as the number of cache buffer segments in Mode Page 8, Byte 13. The firmware default values are set to desktop mode (PM bit = 1), and the
number of cache buffer segments set to 16 (10h). The OEM saved values for drives with LW interface is the
same as the firmware default values. For drives with the LC interface, the OEM saved values are changed to
server mode (PM bit=0), and the number of cache buffer segments are set to 3 (03h). Refer to Tables 9a
through 9f in Section 9.3.2 for drive default values for the PM bit in Mode Page 0, Byte 2 and the number of
cache buffer segments in Mode Page 8, Byte 13.
Caching Parameters page (08h)
Byte 13 (Number of Cache Segments)
Desktop mode 10h (16 segments -- default for LW models)
Server mode 03h (3 segments -- default for LC models)
Unit Attention Parameters page (00h)
Byte 2, Bit 7 (PM bit)
1
0
14 Cheetah 36XL Product Manual, Rev. E
Cheetah 36XL Product Manual, Rev. E 15
5.0 Reliability specifications
The following reliability specifications assume correct host/drive operational interface, including all interface
timings, power supply voltages, environmental requirements and drive mounting constraints (see Section 8.4).
Seek Errors
Less than 10 in 10
Read Error Rates [1]
Recovered Data Less than 10 errors in 10
Unrecovered Data Less than 1 sector in 10
Miscorrected Data Less than 1 sector in 10
MTBF 1,200,000 hours
Service Life 5 years
Preventive Maintenance None required
Note.
[1] Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.
5.1 Error rates
The error rates stated in this specification assume the following:
• The drive is operated per this specification using DC power as defined in this manual (see Section 6.2).
• The drive has been formatted with the SCSI Format command.
• Errors caused by media defects or host system failures are excluded from error rate computations. Refer to
Section 3.2, “Media Characteristics.”
• Assume random data.
8
seeks
12
bits transferred (OEM default settings)
15
bits transferred (OEM default settings)
21
bits transferred
5.1.1 Environmental interference
When evaluating systems operation under conditions of Electromagnetic Interference (EMI), the performance
of the drive within the system shall be considered acceptable if the drive does not generate an unrecoverable
condition.
An unrecoverable error, or unrecoverable condition, is defined as one that:
• Is not detected and corrected by the drive itself;
• Is not capable of being detected from the error or fault status provided through the drive or SCSI interface; or
• Is not capable of being recovered by normal drive or system recovery procedures without operator intervention.
5.1.2 Read errors
Before determination or measurement of read error rates:
• The data that is to be used for measurement of read error rates must be verified as being written correctly on
the media.
• All media defect induced errors must be excluded from error rate calculations.
5.1.3 Write errors
Write errors can occur as a result of media defects, environmental interference, or equipment malfunction.
Therefore, write errors are not predictable as a function of the number of bits passed.
If an unrecoverable write error occurs because of an equipment malfunction in the drive, the error is classified
as a failure affecting MTBF. Unrecoverable write errors are those which cannot be corrected within two
attempts at writing the record with a read verify after each attempt (excluding media defects).
5.1.4 Seek errors
A seek error is defined as a failure of the drive to position the heads to the addressed track. There shall be no
more than ten recoverable seek errors in 10
8
physical seek operations. After detecting an initial seek error, the
drive automatically performs an error recovery process. If the error recovery process fails, a seek positioning
16 Cheetah 36XL Product Manual, Rev. E
error (15h) is reported with a Medium error (3h) or Hardware error (4h) reported in the Sense Key. This is an
unrecoverable seek error. Unrecoverable seek errors are classified as failures for MTBF calculations. Refer to
the
SCSI Interface Product Manual,
5.2 Reliability and service
You can enhance the reliability of Cheetah 36XL disc drives by ensuring that the drive receives adequate cooling. Section 6.0 provides temperature measurements and other information that may be used to enhance the
service life of the drive.
5.2.1 Mean time between failure
The production disc drive shall achieve an MTBF of 1,200,000 hours when operated in an environment that
ensures the case temperatures are not exceeded. Short-term excursions up to the specification limits of the
operating environment will not affect MTBF performance. Continual or sustained operation at case temperatures above the values specified in Section 6.4.1 may degrade product reliability.
The MTBF target is specified as device power-on hours (POH) for all drives in service per failure.
Estimated power-on operating hours in the period = MTBF per measurement period
Estimated power-on operation hours means power-up hours per disc drive times the total number of disc drives
in service. Each disc drive shall have accumulated at least nine months of operation. Data shall be calculated
on a rolling average base for a minimum period of six months.
part number 75789509, for Request Sense information.
Number of drive failures in the period
MTBF is based on the following assumptions:
• 8,760 power-on hours per year.
• 250 average on/off cycles per year.
• Operations at nominal voltages.
• Systems will provide adequate cooling to ensure the case temperatures specified in Section 6.4.1 are not
exceeded.
Drive failure means any stoppage or substandard performance caused by drive malfunction.
A S.M.A.R.T. 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 shall be required.
5.2.3 Service life
The drive shall have a useful service life of five years. Depot repair or replacement of major parts is permitted
during the lifetime (see Section 5.2.4)
5.2.4 Service philosophy
Special equipment is required to repair the drive HDA. In order to achieve the above service life, repairs must
be performed only at a properly equipped and staffed 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. Also, there are no spare parts available for this drive. 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 since there are no user purchasable parts in the drive.
Cheetah 36XL Product Manual, Rev. E 17
5.2.6 Hot plugging Cheetah 36XL disc drives
The ANSI SPI-3 (T10/1302D) document defines the physical requirements for removal and insertion of SCSI
devices on the SCSI bus. Four cases are addressed. The cases are differentiated by the state of the SCSI bus
when the removal or insertion occurs.
Case 1 - All bus devices powered off during removal or insertion
Case 2 - RST signal asserted continuously during removal or insertion
Case 3 - Current I/O processes not allowed during insertion or removal
Case 4 - Current I/O process allowed during insertion or removal, except on the device being changed
Seagate Cheetah 36XL disc drives support all four hot plugging cases. Provision shall be made by the system
such that a device being inserted makes power and ground connections prior to the connection of any device
signal contact to the bus. A device being removed shall maintain power and ground connections after the disconnection of any device signal contact from the bus (see SFF-8046, SCA-2 specification).
It is the responsibility of the systems integrator to assure that no hazards from temperature, energy, voltage, or
ESD potential are presented during the hot connect/disconnect operation.
All I/O processes for the SCSI device being inserted or removed shall be quiescent. All SCSI devices on the
bus shall have receivers that conform to the SPI-3 standard.
If the device being hot plugged uses single-ended (SE) drivers and the bus is currently operating in low voltage
differential (LVD) mode, then all I/O processes for all devices on the bus must be completed, and the bus quiesced, before attempting to hot plug. Following the insertion of the newly installed device, the SCSI host
adapter must issue a Bus Reset, followed by a synchronous transfer negotiation. Failure to perform the SCSI
Bus Reset could result in erroneous bus operations.
The SCSI bus termination and termination power source shall be external to the device being inserted or
removed.
End users should not mix devices with high voltage differential (HVD) drivers and receivers and devices with
SE, LVD, or multimode drivers and receivers on the same SCSI bus since the common mode voltages in the
HVD environment may not be controlled to safe levels for SE and LVD devices (see ANSI SPI-3).
The disc drive spindle must come to a complete stop prior to completely removing the drive from the cabinet
chassis. Use of the Stop Spindle command or partial withdrawal of the drive, enough to be disconnected from
the power source, prior to removal are methods for insuring that this requirement is met. During drive insertion,
care should be taken to avoid exceeding the limits stated in Section 6.4.4, "Shock and vibration" in this manual.
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 a drive failure and is designed to provide sufficient warning of a failure to
allow data back-up before an actual failure occurs.
Note. The firmware will monitor specific attributes for degradation over time but cannot predict instantaneous
drive failures.
Each attribute 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 bit and the PERF bit of the “Informational
Exceptions Control Mode Page” (1Ch). The DEXCPT bit is used to enable or disable the S.M.A.R.T. process.
Setting the DEXCPT bit will disable all S.M.A.R.T. functions. When enabled, S.M.A.R.T. will collect on-line data
as the drive performs normal read/write operations. When the PERF bit is set, the drive is considered to be in
“On-line Mode Only” and will not perform off-line functions.
18 Cheetah 36XL Product Manual, Rev. E
The process of measuring off-line attributes and saving data can be forced by the RTZ command. Forcing
S.M.A.R.T. will reset the timer so that the next scheduled interrupt will be two hours.
The drive can be interrogated by the host to determine the time remaining before the next scheduled measurement and data logging process will occur. This is accomplished by a log sense command to log page 0x3E.
The purpose is to allow the customer to control when S.M.A.R.T. interruptions occur. As described above, forcing S.M.A.R.T by the Rezero Unit command will reset the timer.
Performance impact
S.M.A.R.T. attribute data will be saved to the disc for the purpose of recreating the events that caused a predictive failure. The drive will measure and save parameters once every two hours subject to an idle period on the
SCSI bus. The process of measuring off-line attribute data and saving data to the disc is uninterruptable and
the maximum delay is summarized below:
Maximum processing delay
On-line only delay Fully enabled delay
DEXCPT = 0, PERF = 1 DEXCPT = 0, PERF = 0
S.M.A.R.T. delay times ST336705: 150 ms ST336705: 270 ms
ST318405: 100 ms ST318405: 190 ms
ST39205: 70 ms ST39205: 130 ms
Reporting control
Reporting is controlled in the Informational Exceptions Control Page (1Ch). Subject to the reporting method,
the firmware will issue a 01-5D00 sense code to the host. The error code is preserved through bus resets and
power cycles.
Determining rate
S.M.A.R.T. monitors the rate at which errors occur and signals a predictive failure if the rate of degraded error
rate increases to an unacceptable level. To determine rate, error events are logged and compared to the number of total operations for a given attribute. The interval defines the number of operations over which to measure the rate. The counter that keeps track of the current number of operations is referred to as the Interval
Counter.
S.M.A.R.T. measures error rate, hence for each attribute the occurrence of an error is recorded. A counter
keeps track of the number of errors for the current interval. This counter is referred to as the Failure Counter.
Error rate is simply the number of errors per operation. The algorithm that S.M.A.R.T. uses to record rates of
error is to set thresholds for the number of errors and the interval. If the number of errors exceeds the threshold
before the interval expires, then the error rate is considered to be unacceptable. If the number of errors does
not exceed the threshold before the interval expires, then the error rate is considered to be acceptable. In either
case, the interval and failure counters are reset and the process starts over.
Predictive failures
S.M.A.R.T. signals predictive failures when the drive is performing unacceptably for a period of time. The firmware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accomplish this, a counter is incremented whenever the error rate is unacceptable and decremented (not to exceed
zero) whenever the error rate is acceptable. Should the counter continually be incremented such that it reaches
the predictive threshold, a predictive failure is signaled. This counter is referred to as the Failure History
Counter. There is a separate Failure History Counter for each attribute.
5.2.8 Drive Self Test (DST)
Drive Self Test (DST) is a technology designed to recognize drive fault conditions that qualify the drive as a
failed unit. DST validates the functionality of the drive at a system level.
Cheetah 36XL Product Manual, Rev. E 19
There are two test coverage options implemented in DST:
1. extended test
2. short test
The most thorough option is the extended test that performs various tests on the drive and scans every logical
block address (LBA) of the drive. The short test is time-restricted and limited in length—it does not scan the
entire media surface, but does some fundamental tests and scans portions of the media.
If DST encounters an error during either of these tests, it reports a fault condition. If the drive fails the test,
remove it from service and return it to Seagate for service.
5.2.8.1 DST Failure Definition
The drive will present a “diagnostic failed” condition through the self-tests results value of the diagnostic log
page if a functional failure is encountered during DST. The channel and servo parameters are not modified to
test the drive more stringently, and the number of retries are not reduced. All retries and recovery processes
are enabled during the test. If data is recoverable, no failure condition will be reported regardless of the number
of retries required to recover the data.
The following conditions are considered DST failure conditions:
• Seek error after retries are exhausted
• Track-follow error after retries are exhausted
• Read error after retries are exhausted
• Write error after retries are exhausted
Recovered errors will not be reported as diagnostic failures.
5.2.8.2 Implementation
This section provides all of the information necessary to implement the DST function on this drive.
5.2.8.2.1 State of the drive prior to testing
The drive must be in a ready state before issuing the Send Diagnostic command. There are multiple reasons
why a drive may not be ready, some of which are valid conditions, and not errors. For example, a drive may be
in process of doing a format, or another DST. It is the responsibility of the host application to determine the “not
ready” cause.
While not technically part of DST, a Not Ready condition also qualifies the drive to be returned to Seagate as a
failed drive.
A Drive Not Ready condition is reported by the drive under the following conditions:
• Motor will not spin
• Motor will not lock to speed
• Servo will not lock on track
• Drive cannot read configuration tables from the disc
In these conditions, the drive responds to a Test Unit Ready command with an 02/04/00 or 02/04/03 code.
5.2.8.2.2 Invoking DST
To invoke DST, submit the Send Diagnostic command with the appropriate Function Code (001b for the short
test or 010b for the extended test) in bytes 1, bits 5, 6, and 7. Refer to the
number 75789509, for additional information about invoking DST.
SCSI Interface Product Manual,
part
5.2.8.2.3 Short and extended tests
The short and extended test options are described in the following two subsections.
Each test consists of three segments: an electrical test segment, a servo test segment, and a read/verify scan
segment.
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