seagate ST118202LW, ST118202LC Product Manual
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cheetah 18 Family:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ST118202LW/LC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product Manual, Volume 1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cheetah 18 Family:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ST118202LW/LC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product Manual, Volume 1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
© 1997, 1998 Seagat e Technology, Inc. All rights reserved
Publication number: 83329260, Rev. B
August 1998
Seagate, Seagate Technology, and the Seagate logo are registered trademarks of Seagate Technolo gy,
Inc. Cheetah, SeaFAX, SeaFONE, SeaBOARD, and SeaTDD are either trademarks or registered trademarks of Seagate Tech nology, Inc. or one of its subsidiaries. All other trademarks or registered trademarks are the property of their respective owners.
Seagate reserves the right to chang e, without notice, product offerings or specifications. No part of this
publication may be reproduced in any form without written permission of S eagat e Technology, Inc.
Revision status summary sheet
Revision Date Writer/Engineer Sheets Affected
Rev. A 05/19/98 L. Newman/J. Nowitzke 1/1, v thru viii, 1-69
Rev. B 08/14/98 L. Newman/J. Nowitzke Add Multimode signal input and output
characteristics to Section 9.
Notice.
Product Manual 83329260 is Volume 1 of a two volume document with the SCSI Interface information in
the Volume 2 SC SI Interface P roduct Manual, par t number 7773 8479.
If the SCSI Interface information is needed the Volume 2 Interface Manual should be ordered,
part number 77738479.
Cheetah 18 Product Manual, Rev. B v
Contents
1.0 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 Applicable standards and refe rence 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 descr iption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Standard features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Media characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.4 Reliabili ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.5 Unformatted and formatted capacit ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.6 Programmabl e drive capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.7 Factory installed accessorie s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.8 Options (factory i nstalled). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.9 Accessories (user installed). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.0 Performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1 Internal drive characteristics (transparent to user) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2 SCSI performance characte ristics (visible to user) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.1 Access time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.2 Format comm and exec ution time (minutes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.3 Generalized performance characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.3 Start/stop time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.4 Prefetch/multi-segmented cache control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.5 Cache operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.5.1 Caching write data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.5.2 Prefetch o peration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.0 Reliability specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1 Error rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.1 Environmental inte rference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.2 Read errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.3 Write errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.4 Seek errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.2 Reliability and service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4
5.2.1 Mean time bet ween failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.2 Field failure ra te vs time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.3 Preve ntive maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.4 Service life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.5 Service philosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.6 Service tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.7 Hot plugging Cheetah 18 disc drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.8 S.M.A.R.T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2.9 Product warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.0 Physical/electrical specific ations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.1 AC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.2 DC power requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.2.1 Conduct ed noise immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.2.2 Power sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.2.3 12 V - Current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.3 Power dissipation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.4 Environmental limits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.4.1 Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
vi Cheetah 18 Product Manual, Rev. B
6.4.2 Relative humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
6.4.3 Effective altitude (sea level). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
6.4.4 Shock and vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
6.4.4.1 Shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
6.4.4.2 Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
6.4.5 Air clea nliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
6.4.6 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
6.4.7 Electromagnetic susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
6.5 Mechanical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
7.0 Defect and error management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
7.1 Drive internal defects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
7.2 Drive erro r recovery proced ures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
7.3 SCSI systems errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
8.0 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 1
8.1 Drive ID/option select header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.1.1 Notes for Figures 8, 9, and 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
8.1.2 Function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
8.2 Drive orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
8.3 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
8.3.1 Air flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
8.4 Drive mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
8.5 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
9.0 Interface requiremen ts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
9.1 General d escription. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
9.2 SCSI interface messages supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
9.3 SCSI interface commands supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
9.3.1 Inquiry Vital Product data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
9.3.2 Mode Sense data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
9.4 SCSI bus conditions and miscellaneous features supported . . . . . . . . . . . . . . . . . . . . . . . . .46
9.5 Synchronous data trans fer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
9.5.1 Synchro nous data transfer periods supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
9.5.2 REQ/ACK offset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
9.6 Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
9.6.1 DC cable and connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
9.6.2 SCSI interface physical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
9.6.3 SCSI interface cable requiremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
9.6.4 Mating connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
9.6.4.1 Mating connectors for LW drives. . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
9.6.4.2 Mating connectors for LC drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
9.7 Electrical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8
9.7.1 Multimo de—S E and LV D alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
9.7.1.1 S ingle -ended drivers/receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
9.7.1.2 Low v oltage differential I/O circuits . . . . . . . . . . . . . . . . . . . . . . . . . . .60
9.7.1.3 General cab le characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
9.8 Terminator requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
9.9 Terminator power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
9.10 Disc drive SCSI timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
10.0 Seagate technical support services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
Cheetah 18 Product Manual, Rev. B vii
List of Figures
Figure 1. Cheetah 18 family drive (ST118202LW shown). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Cheetah 18 family drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 3. Typical Cheetah 18 family drive +12 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 4. Locations of PCBA com ponent s listed in Table 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 5. Recommended mo unting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 6. ST118202LW m ount ing conf iguration dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 7. ST118202LC mo unting co nfiguration dim ensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 8. J6 jumper header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Figure 9. J5 jumper header (on LW models only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 10. J2 optio n select header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 11. Air flow (suggested) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 12. ST1182 02LW drive phy sical interface (68-pin J1 SCSI I/O connector) . . . . . . . . . . . . . . . . . 48
Figure 13. ST1182 02LC drive phy sical interface (80-pin J1 SCSI I/O connector) . . . . . . . . . . . . . . . . . 48
Figure 14. SCSI daisy chain interface cabling LW drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Figure 15. Nons hie lded 68 pin SCSI device co nnecto r used on LW drives . . . . . . . . . . . . . . . . . . . . . . 52
Figure 16. Nonshie lded 80 pin SCSI “SCA-2” connecto r, used on LC drives . . . . . . . . . . . . . . . . . . . . . 53
Figure 17. LVD outpu t signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Figure 18. Typical SE-LVD alternative transmitter receiver circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Cheetah 18 Product Manual, Rev. B 1
1.0 Scope
This manual describes Seagate Technology®, Inc. Cheetah 18™ disc drives.
Cheetah 18 drives support t he small comput er system interface (SCSI) as described in the ANSI SC SI, SCSI-
2, and SCSI -3 (Fast-20 and Fast-40) interface specifications t o th e extent described in t his manual. The
Interface Product Manual
other families of Seagate drives.
From this point on in this product manual the reference to Cheetah 18 models is referred to as “the drive”
unless references to individual models are necessary.
(part number 77738479) describes general SCSI interface characteristics of this and
SCSI
*
Figure 1. Cheetah 18 family drive (ST118202LW shown)
Cheetah 18 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 hos t equipment to provide adeq uate power and environment in order to a chieve optimum performance and compliance with applicable industry a nd governmental regulations. Special attention
must be given in the areas of safety, power distribution, shielding, audible noise control, and temperature regulation. In par ticular, the drive must be securely m ount ed in o rder to guarante e th e spec ified pe rformanc e characteristics. Mounting by bottom holes must meet the requirements of Section 8.4.
2.1 Standards
The Cheetah 18 family complies with Sea gate standards as noted in the appropriate sec tions of this Manual
and the Seagate
The Cheetah 18 disc drive is a UL recognized com ponent per U L1950, CS A cer tified to CS A C22.2 No. 950M89, and VDE certified to VDE 0805 and EN 60950 .
2.1.1 Electromagnetic compatibility
The drive, as delivered, is designed f or system integration and installation into a suitable enclosure prior to use.
As such the drive is supplied as a subassembly and is not subjec t 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 do es not provide adeq uate shielding. If the I /O cables are extern al 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 77738479 (Vol. 2).
2.1.2 Electromagnetic susceptibility
As a component assem bly, the drive is not required to me et any suscep tibility perform ance requi rements. It is
the responsibility of those integrating the dri ve within their systems to perform t hose t ests req uired a nd des i gn
their system to ensure that equipm ent operating in the same system as the drive or external to the system
does not adversely affect the perf ormance of the drive. S ee Section 5.1.1 and Table 2, DC power requi rements.
2.2 Electromagnetic compliance
Seagate uses an independen t laboratory to confirm com pliance 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:
• 486, Pentium, and PowerPC microprocessors
• 3.5-inch floppy disc drive
• Keyboard
• Monitor/display
• Printer
• External modem
•Mouse
Although the test system with this Seagate m odel com pli es to the direct ives/standard(s), we cannot guarantee
that all systems will comply. The computer manufacturer or system integrator shall confirm EMC compli ance
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 Electromagnet ic
Compatibility Directive 89/336/EEC of 03 M ay 198 9 as amended by Directive 92/31/EEC of 28 A pri l 19 92 a nd
Directive 93/68/EEC of 22 July 1993.
4 Cheetah 18 Product Manual, Rev. B
Australian C-Ti ck
If this model has the C-Tick Marking it complies with the Au stralia/New Zealand Standard AS/NZS3548 1995
and meets the Electromagnetic Compatibility (EMC) Framework requirements of Aust ral ia’s Spectrum Management Agency (SMA).
2.3 Reference documents
Cheetah 18 Installation Guide
SCSI Interface Product Manual
ANSI small computer system interface (SCSI) document numbers:
X3.131-1994 SCSI-2
X3.253-1995 SCSI-3 Parallel Interface
T10/1142D Rev. 14 SPI-2 (SCSI-3 Parallel Interface version 2)
SFF-8046 Specification for 80-pin connector for SCSI disk drives
SCA-2 EIA Speci fication ANSI/EIA
68-pin EIA # 3652
Package Test Specification Seagate P/N 30190-001 (under 100 lb.)
Package Test Specification Seagate P/N 30191-001 (over 100 lb.)
Specification, Acoustic Test Requirements, and Procedures Seagate P/N 30553-001
In case of conflict between this document and any referenced document, this document takes precedence.
Seagate P/N 83329250
Seagate P/N 77738479
Cheetah 18 Product Manual, Rev. B 5
3.0 General description
Cheetah 18 drives combine magne toresistive (MR) heads, par tial response/ maximum likelihood (PRML) re ad
channel electronics, embedded servo technology, and a wide Ultra2 SCSI interface to provide high performance, high capacity data storage for a variety of systems including engineering workstations, network servers, mainframes, and supercomputers.
Ultra SCSI and Ultra2 SCSI use negotiated transfer rates. These transfer rates will occur only if your host
adapter support s these data transfer rates and is compatible with the required h ardware requirements of the
I/O circui t type. This dr ive also o perates at SCS I-1 and SCSI-2 d ata tra nsfer rates for back ward comp atibilit y
with non-Ultra/Ultra2 SCSI host adapters.
Table 1 lists the features that differentiate the two Cheetah 18 models.
Table 1: Drive model number vs. differentiating features
Number
Model number
of heads I/O circuit type [1]
ST118202LW 24 Multimode—single-ended (SE)
Number of I/O
connector pins
Number of I/O
data bus bits
68 16
and low voltage differential (LVD)
ST118202LC 24 Multimode—single-ended (SE)
80 16
and low voltage differential (LVD)
[1] See Section 9.6 for details and definitions.
The drive records and recovers data on approximately 3-inch (84 mm) non-removeable discs.
The drive supports the Small Computer System Interface (SCSI) as desc ribed in the ANSI S CSI -2/SCSI-3
interface specifications to the extent described in this manual (volume 1), which defines the product performance characteristics of the Cheetah 18 family of dr ives, and the
SCSI Interface Product Manual
(volume 2),
part number 77738479, which describes the general interface characteristics of this and other families of
Seagate SCSI drives.
The drive’s interface supports multiple initiators, disconnect/reconnect, self-configuring host software, and
automatic features that relieve the host from the necessity of knowing the physical characteristics of the targets
(logical block addressing is used).
The head and disc assembly (HDA) is sealed at the factory. Air circulates within the HDA through a nonreplaceable filter to maintain a contamination-free HDA environment.
Refer to Figure 2 for an exploded view of the drive. This exploded view is for information only—never disassemble the HDA a nd do not attempt to ser vice 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 18 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.
An automatic shipping lock prevents potential damage to the heads and discs that results from movement during shipping and handling. The shipping lock autom atically diseng ages when power is applied t o the drive and
the head load process begins.
Cheetah 18 drives decode track 0 location data from t he servo data em bedded on each surface to eliminate
mechanical transducer adjustments and related relia bilit y con ce rns.
A high-performance actuator assembly with a low-inertia, balanced, pa tent ed, straight-arm desi gn provi des
excellent performance with minimal power dissipation.
6 Cheetah 18 Product Manual, Rev. B
Figure 2. Cheetah 18 family drive
Cheetah 18 Product Manual, Rev. B 7
3.1 Standard features
The Cheetah 18 family has the following standard features:
• Integrated Ultra/Ultra2 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 by te sector sizes from 180 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 correction capability up to 185 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 Interl eave
• Zoned bit recording (ZBR)
• Vertical, horizontal, or top down mounting
• Dynamic spindle brake
• 1,024 kbyte data buffer (or 4,096 kbyte option)
• Hot plug compatibility (Section 9.6.4.2 lists proper host connector needed) for “LC” model drives
• SCAM (SCSI Configured AutoMagically) plug-n-play l evel 2 compliant, factory set to level 1
3.2 Media characteristics
The media used o n the drive has a diameter of ap proximately 3 inches (84 mm). The alumi num substrate is
coated with a thin film magnetic material, overcoated with a proprietar y protec tive layer for i mproved durability
and environmental protection.
3.3 Performance
• Supports industry standard Ultra2 SCSI interface
• Programmable multi-segmentable cache buffer (see Section 3.1)
• 10,025 RPM spindle. Average latenc y = 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
• 1,000,000 hour MTBF
• LSI circuitry
• Balanced low mass rotary voice coil actuator
• Incorporates industr y -standa rd Self-Monitoring, Analysis and Reporting Technology (S.M.A.R. T.)
• 5-year warranty
8 Cheetah 18 Product Manual, Rev. B
3.5 Unformatted a n d formatted capacities
Formatted capacity depends on the number of spare reallocation sectors reserved and the number of bytes per
sector. The following table shows the standard OEM model capacities:
Formatted
data block size
512 bytes/sector [1] Unformatted
ST118202 021EB38Fh (18.210 GB) [2] 22.54 GB
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 di fferent formatted capacities than those listed. See
Mode Select Command and Format Command in the
SCSI Interface Product Manual
, part number
77738479.
[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
Table 5.2.1-13 in the
SCSI Interface Product Manual
, part number 77738479, Rev. H. 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 t he capacity it is current ly formatted to have. A number in the num ber of blocks field that is
less than the max imum number of LB As changes the total drive capac ity to the value in the block d escriptor
number of blocks field. A value greater than the m aximum number of LBAs is rou nded d own to the ma ximum
capacity.
3.7 Factory installed accessories
OEM Standard dr ives are shipped wit h the
Cheetah 18 Installation Guide
, part number 83329250 (unless otherwise specified). The factory also ships with the drive a small bag of jumpe r plugs used for the J2, J5, and J6
option select jumper headers.
3.8 Options (factory installed)
All customer reques ted options are inco rporated during prod uction or packaged at the manufactur ing facility
before shipping. Some of the options available are (not an exhaustive list of possible options):
• Other capacities can be ordered depending on sparing scheme and secto r size requested.
• 4 Mbyte optional buffer size.
• Single unit shipping pack. T he drive is n ormally ship ped in bulk packaging to provide m aximum protecti on
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 18 Installation Guide
, part number 83329250, i s u sually included with each standard OE M
drive shipped, but extra copies may be ordered.
3.9 Accessories (user installed)
The following accessories are available. All accessories may be installed in the field.
• Single unit shipping pack.
Cheetah 18 Product Manual, Rev. B 9
4.0 Performance characteristics
4.1 Internal drive characteristics (transparent to user)
ST118202
Drive capacity 18.210 GByte (formatted, rounded off values)
Read/write he ads 24
Bytes/track 104,840–159,008 Bytes (average, rounded off values)
Mbytes/surface 939 Mbytes (unformatted, rounded off values)
Tracks/surface (total) 6,962 Tr acks (user accessible)
Tracks/inch 8,962 TPI
Peak bits/inch 183 KBPI
Internal data rate 152-231 Mbits/sec (variable with zone)
Disc rotational speed 10,025 r/min
Average rotational latency 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 18 family unless otherwise specified.
Refer to Section 9.10 and to the
details.
SCSI Interface Product Manual
, part number 77738 479, for additional timing
4.2.1 Access time [5]
Including controller overhead
(without disconnect) [ 1] [3]
Drive level
Read Write
msec
Aver age – Typical [2] 6.0 6.8
Single Track – Typical [2] 0.8 1.1
Full Stroke – Typical [2] 12.2 13.2
4.2.2 Format command execution time (minutes) [1]
ST118202
Maxim um (with verify) <60
Maximum (no verify) <30
4.2.3 Generalized performance characteristics
Minimum sector interleave 1 to 1
Data buffer transfer rate to/from disc media (one 512-byte sector):
Min. [3]* 19.0 MByte/sec
Avg. [3] 23.95 MByte/sec
Max. [3] 28.9 MByte/sec
SCSI interface data transfer rate (asynchronous):
Maximum instantaneous one byte wide 5.0 Mbytes/sec [4]
Maximum instantaneous two bytes wide 10.0 Mbytes/sec [4]
Synchronous transfer rate for SCSI Fast-40 (Ultra2 SCSI):
In single-ended (SE) interface mode 5.0 to 40 Mbytes/sec
In low voltage differential (LVD) interface mode 5.0 to 80 Mbytes/sec
10 Cheetah 18 Product Manual, Rev. B
Sector Sizes:
Default 512 byte user data blocks
Variable 180 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.)
Overhead time for head switch (512 byte sectors) in sequential mode 0. 8 msec
Overhead time for one track cy linder switch in sequential mode 1.2 msec (typical)
Average rotational latency 2.99 msec
Notes for Section 4.2.
[1] Execution time measured from receipt of the last By te of the Command Descriptor Block (CDB) to the
request for a Status Byte Tr ansf er to the Initiator (excluding connect/disconnect).
[2] Typical acce ss times are meas ured under nom inal conditions of te mperature, 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 suppor t the rates listed and no cable loss.
[5] Access time = controller overhead + average seek time.
Access to data = controller overhead + avera ge seek time + latency time.
4.3 S tar t/stop ti me
After DC power at nominal voltage has been applied, the drive becomes ready within 30 seconds if the Motor
Start Opt ion is disabled (i.e. the m otor star ts as soon as the power has be en applied). If a recoverable error
condition is detected during the star t sequence, the drive executes a recovery procedure which may cause the
time to become ready to exceed 30 seconds. During spin up to read y 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 30 seconds from removal of DC power.
Negligible
If the Motor Start Opt ion is enabled, the internal cont roller accepts the comm ands listed in the SC SI Interface
Product Manual less than 3 seconds after DC power has been applied. After the Motor Start Command has
been received the drive becomes ready for normal operations within 30 seconds typically (excluding an error
recovery procedure). The M otor Star t Command can also be used to command the drive to stop the spindle
SCSI Interface Product Manual
(see
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 77738479. Prefetch and cache operation are independent features from the standpoint that each is
enabled and disabled independently via the Mode Select command. However, in actual operation the prefetch
feature overlaps cache operation somewhat as is noted in Section 4.5.1 and 4.5.2.
All default cache and prefetch Mode parameter values (Mode Page 08h) for standard OEM versions of this
drive family are given in Tables 8.
4.5 Cache operation
In general, 840 Kbytes (3,700 kbytes of the 4,096 kbytes on units with this option) of the physical buffe r 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 main-
, part number 77738479).
SCSI Interface Product Manual,
part
Cheetah 18 Product Manual, Rev. B 11
tains a table of logical block disk m edium addresses of the dat a st ored i n ea ch segm ent of t he buffer. If cache
operation is enabled (RCD bit = 0 in Mode Page 08h, byte 2, bit 0. See
number 77738479), data requested by the host with a Read command is retrieved from the buffer (if it is there),
before any disc access is initiated. If cache operation is not enabled, the buffer (still segmented with required
number of segments) is still used, but only as circular bu ffe r 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
The following is a simplified description of a read operation with cache operation enabled:
Case A - A Read command is received and the first logical block (LB) is already in cache:
1. Dri ve transfers to the initiator the first LB requested plus all subsequent contiguous LBs that are alre ady 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 t he cac he to the hos t in accordance with the disconnect /recon nec t sp ecification m entioned 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 transf ers t hem 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.
SCSI Interface Product Manual,
SCSI Interface Product Manual
part
.
Each buffer segment is actually a self-contained circular storage (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 ov erall 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 segm ents may be selected using the Mode Select com mand, but the size
can not be directly selected. Size is selected on ly as a by-product of sele cting t he s egm ent num ber s pecification. The size in Kbytes of each segment is not reported by the Mode Sense command page 08h, bytes 14 and
15. The value 0XFFFF is always reported. If a size specification is sent by the 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 on e, the drive responds as it doe s for any attempt to change unchan geable parameters (see
SCSI Interface Product Manual,
of segments from 1 to 16. Default is three segments.
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 dat a 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), t hen dat a written to the medium is retained in the cache to be made available for future read cache hi ts. The s am e buffer space and s egm entat ion is used as set up for read functions.
The buffer segmentation scheme is set up or changed indep endently, 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 subs equen t Read command s.
If the number of write dat a logical blocks exceeds the size of the segment being wr itten 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. Howev er, the drive does not overwrite data that has not
yet been written to the medium.
part number 77738479). The drive supports operation of any integer number
If write caching is enabled (WCE=1), then t he drive may return GOOD status on a wri te command after the
data has been transferred into the cache, but before the data has been written to the medium. If an error occurs
12 Cheetah 18 Product Manual, Rev. B
while writing the dat a to the medium, and G OOD status has already bee n 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 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 i mmedi ately 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 t hat reques t 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 s egment(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 bo undary to fetch more data only if the Di scontinuity
(DISC) bit is set to one in bit 4 of byte 2 of Mode parameters page 08h.
Whenever prefetc h (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, A RLA enables prefetch of contiguous blocks
from the disc when it sens es that a prefetch hit will likely occur, even if two consecutive read operations were
not for phy sically contiguous bloc ks of data (e .g. “software interleav e”). 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.
Cheetah 18 Product Manual, Rev. B 13
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 tha n 10 errors in 10
Unrecovered Data Less than 1 sector in 10
Miscorrected Data Less than 1 sector in 10
MTBF 1,000,000 hours
Service Life 5 years
Preventive M aintenance 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 def ined 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 defa ult settings)
21
bits tran sferred
5.1.1 Environmental interference
When evaluating syste ms operation under conditions of Electromagnetic Interference (EMI), th e performance
of the drive within the system shall be considered acc eptable if the drive does not g enerate 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 v erifi ed as being written correctly on
the m edia.
• All media defect induced errors must be excluded from error rate calculations.
5.1.3 Write errors
Write errors can occur a s 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 cl assified
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 (exc luding media defects).
5.1.4 Seek errors
A seek error is defined as a failure of the drive to position the heads to the addres sed t rack. There shal l 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
error (15h) is reported with a Medium error (3h) or Hardware error (4h) rep orted in the Sense Key. This is an
14 Cheetah 18 Product Manual, Rev. B
unrecoverable seek error. Unrecoverable seek errors are classified as failures for MTBF calculations. Refer to
Section 5.1.1.2 of the
SCSI Interface Product Manual,
part number 77738479, for Request Sense information.
5.2 Reliability and service
You can enhance the reliability of Cheetah 18 disc drives by ensuring that the drive receives adequate cooling.
Section 6.0 provides temperature measurem ents and other information that may be used to enhance t he service life of the drive. Section 8.3.1 provides recommended air-flow information.
5.2.1 Mean time between failure
The production disc dri ve shall achieve an MTBF of 1,000,000 hours w hen operated in an environment that
ensures the case temperatures specified in Section 6.4.1, T able 3 are not exceeded. Short-term excursions up
to the specification limits of the operating environment will not af fec t MTBF performance. Continual or sus tained operation at case temperatures above the values shown in Table 3 may degrade product reliability.
The MTBF target is specified as device power-on hours (POH) for all drives in service per failure.
Estimated power-on operating hours in the period
MTBF per measurement period =
Number of drive failures in the period
Estimated power-on operation hours means power-up hours per disc drive times the total number of disc drives
in 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 perio d of six months.
MTBF is based on the following assumptions:
• 8,760 power-on hours per year.
• 250 average on/off cycles per year.
• Read/seek/write operation 20% of power-on hours.
• Operations at nominal voltages.
• Systems will provide adequate cooling to ensure the case te mperatures specified in Section 6.4.1 are not
exceeded.
Drive failure means any s t oppag e or substandard perform ance caus ed 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 Field failure rate vs time
The expected field failure rate is listed below. Drive utilization will vary. An estimated range of utilization is:
• 720 power-on hours (POH) per month.
• 250 on/off cycles per year.
• Read/seek/write operation 20% of power-on hours.
• Systems will provide adequate cooling to ensure the case te mperatures specified in Section 6.4.1 are not
exceeded.
Month 1 2,364 PPM
Month 2 1,422 PPM
Month 3 1,403 PPM
Month 4 1,391 PPM
Month 5 1,317 PPM
Month 6 1,255 PPM
Month 7 1,162 PPM
Month 8+ 1,025 PPM
Failure rate is calculated as follows:
• No system-induced failures are counted
• PPM targets include 30% no defect found and handling failures
• Based on 1,000,000 MTBF and 720 power-on hours per month
• Month 1’s rate includes a 300 PPM installation failure
Cheetah 18 Product Manual, Rev. B 15
5.2.3 Preventive maintenance
No routine scheduled preventiv e maintenance shall be required.
5.2.4 Service life
The drive shall have a usef ul service life of five years. Depo t repair or replacement of major parts is permitt ed
during the lifetime (see Section 5.2.5).
5.2.5 S e rvi c e 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 st affed service and repai r facility. Troubleshooting and repair of
PCBs in the field is not rec ommended, because of the extensive diagnost ic equipment required for effective
servicing. Also, there are no spare parts available for this drive. Drive warranty is vo ided if the HDA is opened.
5.2.6 Service tools
No special tools are required for site installation or recommended for site maintenance. Refer to Section 5.2.5.
The depot repair philosophy of the drive precludes the necessity for special tools. Field repair of the drive is not
practical since there are no user purchasable parts in the drive.
5.2.7 H ot pl ugging Chee ta h 1 8 dis c dri ve s
The ANSI SPI-2 (T10/1142D) docum ent 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 18 disc drives suppo rt all four hot plugging cases. Provision shall be made by the system
such that a device being insert ed makes power and ground connections pri or 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 inser ted or removed shall be quiesce nt. All SCSI devices on the
bus shall have receivers that conform to the SPI-2 standard.
If the device being hot plugged uses single-ended (SE) drivers and the bus is currently operating in low voltage
differential (LVD) mod e, then a ll I /O processes for all devices on the bus must be completed, and t he bus q uiesced, before attempting to hot plug. Following the insertion of the newly installed device, the SCSI host
adapter must issue a B us Rese t, 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-2).
The disc drive spindle must come to a complete stop pri or 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.
16 Cheetah 18 Product Manual, Rev. B
5.2.8 S.M.A.R.T.
S.M.A.R.T. is an acronym for Self-Monitoring Anal ysis and Repor ting Techn ology. This tec hnology 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 a n actual failure occurs.
Note. The firmware will monitor specific attributes for degradation over time b ut cannot predict instantaneous
drive failures.
Each attribute has been selecte d to m onitor a spec ific s et of failure conditions in th e operat ing pe rformanc e of
the drive, and the thresholds are optimized to minimize “false” and “fa iled” predictions.
Controllin g S.M.A.R.T.
The operating mode of S.M.A.R.T. is controlled by the DEXCP T bit and the PERF bit of the “Informational
Exceptions Control Mode Page” (1Ch). The DEXCPT bit i s used to e nable 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.
The process of measuring of f-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 schedu led interrup t 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, f orcing 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 t o 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 50 milliseconds 300 milliseconds
Repor tin g c on t rol
Reporting is controlled in the Informational Exceptions Control Page (1Ch). Subject t o the repor ting method,
the firmware will issue a 01-5D00 sense c ode to t he ho st. The e rror code is preserved through bus resets and
power cycle s.
Determining rate
S.M.A.R.T. monitors the rate at which errors occur an d sig nals a predictive failure if the rate of degraded error
rate increases to an unacceptable level. To determ ine rate, error events are logged and compared to the num ber of total operations for a gi ven 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 Inter val
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 t he num ber 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 t he number of errors and the interval. If the number of errors e xceeds the threshold
before the interval expires, then the error rate is considered to be unacceptable. If th e 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.
Loading...