seagate ST34501 Installation guide
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Cheetah 4LP Family:
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ST34501N/W/WC/WD/DC
Product Manual, Volume 1
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Cheetah 4LP Family:
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ST34501N/W/WC/WD/DC
Product Manual, Volume 1
© 1997 Seagate T echnology, Inc. All rights reserved
Publication number: 83329120 , Rev. B
July 1997
Seagate, Seagate Technol ogy, and the Seagate l ogo are registered tradem arks of Seagate Technology, Inc. Cheetah, SeaFAX, SeaFONE, SeaNET, SeaTDD, and SeaBOARD are either tradema rks or
registered trademarks of Seagate Technology, Inc. or one of its subsidiaries. All other trademarks o r
registered trademarks are the property of their respective owners.
Seagate reserves the right to change, without not ice, product offerings or specifications. No part of
this publication may be reproduced in any form without written permission of Seagate Technology, Inc.
Revision status summary sheet
Revision Date Writer/Engineer Sheets Affected
A Issue 04/07/97 D. Ashby/G. Olson 1/1, v thru vii, 1 thru 78
B 06/26/97 D. Ashby/G. Olson 9, 10, 14, 15, 18, 20, 22, 29, 30, 49,
52, 56, and 69.
Notice.
Product Manual 83329120 is Volume 1 of a two-volume document with the SCSI interface information in
the Volume 2,
If the SCSI interface information is needed, the Volume 2 interface manual should be ordered, part
number 77738479.
SCSI Interface Product Manual
, part number 77738479.
Cheetah 4LP Product Manual, Rev. B v
Contents
1.0 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 Applicable standards and reference documentati on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Standards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1 Electromagnetic com pati bili ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.2 Electromagnetic susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2 Electromagne tic compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3 Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.0 General descri p tion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Standard features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Media characteristic s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.4 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.5 Unformatt ed and formatted capacit ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.6 Programmabl e drive capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.7 Factory installed accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.8 Options (factory install ed ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.9 Accessories (user installed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.0 Performa nce cha racteri sti c s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 command executi on time (minute s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.3 Generalized performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.3 Start/st op tim e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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
5.0 Reliabil ity sp eci ficati on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1 Error rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.1 Environmental interference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.2 Read errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.3 Write errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.4 Seek errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3
5.2 Reliability and service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.1 Mean time between failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.2 Preventive maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.3 Service life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.4 Service philosophy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.5 Service tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.6 Hot plugging Cheetah 9 disc drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2.7 S.M.A.R.T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.8 Product warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.0 Physical/electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.1 AC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.2 DC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.2.1 Conducted noise immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.2.2 Power sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8
6.2.3 12 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.3 Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.4 Environmenta l limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.4.1 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
vi Cheetah 4LP Product Manual, Rev. B
6.4.2 Relative humidit y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
6.4.3 Effective altitude (sea level). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
6.4.4 Shock and vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
6.4.5 Air cleanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
6.4.6 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
6.4.7 Electromagnetic susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
6.5 Mechanical specif icati ons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
7.0 Defect and error man agem e nt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
7.1 Drive internal defects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
7.2 Drive error recovery procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
7.3 SCSI systems errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
8.0 Installati on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.1 Drive ID/option select h ea der . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.1.1 Notes for Figures 9, 10, and 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
8.1.2 Function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
8.2 Drive orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
8.3 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
8.3 . 1 A i r fl o w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
8.4 Drive mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
8.5 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
9.0 Interface requiremen t s. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
9.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
9.2 SCSI interface messages supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
9.3 SCSI interface command s supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
9.3.1 Inquiry Vital Product data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 3
9.3.2 Mode Sense data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
9.4 SCSI bus conditions and miscellaneous features support ed . . . . . . . . . . . . . . . . . . . . . . . . .47
9.5 Synchronous data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
9.5.1 Synchronous data transfer periods supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
9.5.2 REQ/ACK offset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
9.6 Physi cal interf ac e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
9.6.1 DC cable and connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
9.6.2 SCSI interface physical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
9.6.3 SCSI interface cable requiremen ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
9.6.4 Mating connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
9.7 Electrical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
9.7.1 Single-ended drivers/receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
9.7.2 Differential drivers/receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
9.8 Terminator re quirem ent s. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
9.9 Terminator power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
9.10 Disc drive SCSI timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
10.0 Seagate technical support servi ces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
Cheetah 4LP Product Manual, Rev. B vii
Figur e s
Figure 1. Cheetah 9 family drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Cheetah 9 family drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 3. Typical Cheetah 9 family drive +12 V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 4. Locations of PCB components listed in Table 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 5. Recommended mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 6. Mounting configurati on dim ensions for m odel “N ” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 7. Mounting configurati on dimensions for m odels “W” and “WD ”. . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 8. Mounting configurati on dimensions for m odels “WC” and “DC”. . . . . . . . . . . . . . . . . . . . . . . 27
Figure 9. Model “N” option select jumper connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Figure 10. Cheetah 9 family drive ID select for models “W” and “WD” . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 11. Model ST19101WC/ DC option select jum per connecto rs . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 12. Air flow (suggested) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Figure 13. Physical interface for “N” model drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Figure 14. Model “W” and “WD” drive physical interface (68-pin J1 SCSI I/O connector). . . . . . . . . . . . 50
Figure 15. Model “WC” and “DC” drive physical interface (80-pin J1 SCSI I/O connector and
DC power connector) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 0
Figure 16. SCSI daisy-chain interface cabling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Figure 17. Nonshielded 50-pin SCSI device connector used on “N” models . . . . . . . . . . . . . . . . . . . . . 55
Figure 18. Nonshielded 68-pin SCSI device connector used on “W” and “WD” models . . . . . . . . . . . . . 56
Figure 19. Nonshielded 80-pin SCSI “SCA-2” connector used on “WC” and “DC” models. . . . . . . . . . . 57
Figure 20. Single-ended transmitters and receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Figure 21. Typical differential I/O line transmitter/receiver and external terminat ors . . . . . . . . . . . . . . . 66
Cheetah 4LP Product Manual, Rev. B 1
1.0 Scope
This manual describes the Seagate Technology®, Inc. Cheetah 4LP ™ disc drives.
Cheetah 4LP drives support the small cumputer system interface (SCSI) as described in the ANSI SCSI,
SCSI-2, and SCS I-3 (Fast-20) in terface specif ications to the e xtent de scribed in this ma nual. The
face Product Manual
(part number 77738479) describes general SCSI interface characteristics of this and
other families of Seagate drives.
From this point on in this product m anual the refere nce to Cheetah 4LP models is referred to as “the drive”
(unless references to individual models are necessary).
SCSI Int er-
*Model “N” version with 50-pin SCSI I/O connector
Figure 1. Cheetah 4LP family drive
Cheetah 4LP Product Manual, Rev. B 3
2.0 Applicable standards and reference documentation
The drive has been developed as a system peripheral to the highest standards of design and construction. The
drive depends upon its host equipm ent to provide adequate power and environment in order to achieve optimum performance a nd compliance with applicable industry and g overnmental regulations. Special atte ntion
must be given in the areas of safety, power distribution, shielding, audible noise control, and temperature regulation. In particular, the drive must be se curely mo unte d in order to guarant ee the spe cifi ed performa nce characteristics. Mounting by bott om holes must meet the requirem ents o f Section 8.4.
2.1 Standards
The Cheetah 4LP family com pli es wit h Seagat e st andards a s not ed i n the appropria te section s of this manua l
and the Seagate
The Cheetah 4LP dis c drive is a UL recognized component per UL1950, CSA certif ied to CSA C22. 2 No. 950M89, and VDE certified to VDE 0805 and EN60950.
2.1.1 Electromagnetic compatibility
The drive, as delivered, is designed for s ystem integration and i nstallation into a suitable enclosure prior to
use. As such the drive is suppl ied as a subassembly and is not subject to Subpart B o f Part 15 of the FCC
Rules and Regulations nor the Radio Interference Regulations of the Canadian Departmen t of Communications.
The design characteristics of the drive serve to minimize radiation when inst alled 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 shiel ding. If the I/O cables are ext ernal to
the enclosure, shielded cables should be used, with the shields grounded to the enclosure and to the host controller.
SCSI Interface Product Manual
(volume 2), part number 77738479.
2.1.2 Electromagnetic susceptibility
As a component assembly, the drive is not required to meet any susceptibility performance requirem ents. It is
the responsibility of those integrati ng t he drive wi thin their system s t o perform t hose tests re quired a nd desig n
their system to ensure that equipmen t operating in the same system as the drive or external to the sy stem
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 independen t laboratory to confirm compliance to the d irectives/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 platf or m s. The system confi gurati ons 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 model complie s to the directives/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.
Electromagneti c com pli ance for the Europe an Uni on
If this model has the CE Marking it complies with the European Union requirements of the Electrom agnetic
Compatibility Di rective 89/3 36/ EEC o f 03 May 1989 as am ende d by Directive 92/3 1/EE C of 28 April 1 992 a nd
Directive 93/68/E E C of 22 Jul y 199 3.
4 Cheetah 4LP Product Manual, Rev. B
Australian C-Tick
If this model has the C-Tick Marking it complies with the Australia/New Zealand Standard AS/NZS3548 1995
and meets the Electrom agnetic Compatibilit y (EMC) Framewor k requirement s of Australia’s Spectrum Management Agency (SMA).
2.3 Reference documents
Cheetah 4LP Installat ion Gu ide
SCSI Interface Product Manual
ANSI small computer system interface (SCSI) document numbers:
X3.131-1994 SCSI-2
X3T10/855D rev. 15a SPI
X3T10/1071D rev. 6 Fast-20 (also called “Ultra SCSI”)
SFF-8046 Specification for 80-pin SCA connector for SCSI disk drives
Package Test Spe cification Seagate P/N 30190-001 (under 100 lb.)
Package Test Speci fication Seagate P/N 30191-001 (over 100 lb.)
In case of conflict between this document and any referenced document, this document takes precedence.
(volume 2) Seagate P/N 77738479
Seagate P/N 83329110
Cheetah 4LP Product Manual, Rev. B 5
3.0 General description
Cheetah 4LP drives combine magnetoresistive (MR) heads, partial response/maximum likelihood (PRML) read
channel electronics, embedded servo technology, and a SCSI-3 (Fast-20) interface to provide high performance, high capacity dat a storage for a variety of systems including engineering workstations, network servers, mainframes, and supe rcompu ters.
Fast-20 (also known as Ult ra SCS I) is a negotiated transfer rat e. This transfer rate w ill o ccur only if your host
adapter also supports Fast-20 data transfer rates. This drive also operates at SCSI-1 and SCSI-2 data transf er
rates for backward compatibility with non-Fast-20 capable SCSI host adapt ers.
Table 1 lists the features that differe ntia te the various Che etah 4LP SCSI -3 Fast -20 (Ul tra SCSI ) mode ls.
Table 1. Dri ve model number vs. differentiati ng featur e s
Model number
Number
of heads I/O circuit type
Number of I/O
connector pins
Number of I/O
data bus bits
ST34501N 8 single-ended 50 8
ST34501W 8 single-ended 68 16
ST34501WD 8 differential 68 16
ST34501WC 8 single-ended 80 16
ST34501DC 8 differential 80 16
The drive records and recovers data on 3.5-inch (86 mm) non-removeable discs.
The drive supports the Smal l Computer System Interf ace (SCSI) as described in the ANSI SCSI-2 interface
specifications to the extent described in this manual (volume 1), which defines the product perform ance characteristics of the Cheetah 4LP family of drives, and the
SCSI Interface Product Manual
(volume 2), P/N
77738479, which describes the general interface characteristics of this and other families of Seaga te 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 contami nati on-fre e HDA environment .
Refer to Figure 2 for a n exploded view of the drive. This explo ded view is for information on ly—never disassemble the HDA and do not attempt to service it em s in t he s e a led enclosure (heads, m edia, actuator, etc.) as
this requires special facilities. The drive contains no replaceable parts. Opening th e HDA voids your warranty.
Cheetah 4LP drives use a dedicated landing zone at the innermost radius of the media to eliminate the possibility of destroying or degradi ng data b y landing in the data zone. The dri ve automa tically goes t o the landin g
zone when power is removed.
An automatic shipping lock prevents potential damage to the heads and discs that results from movement during shipping and handlin g. The shippi ng lock aut omatical ly disengage s wh en power is appl ied to the dri ve and
the head load process begins.
Cheetah 4LP drives decode track 0 location data from the servo data embedded on each surface to eliminate
mechanical transd ucer adjustm ent s and related reliability concerns.
A high-performance actuator assembly with a low-inertia, balanced, patented, straight-arm design provides
excellent performance with minim al power dissipation.
6 Cheetah 4LP Product Manual, Rev. B
Figure 2. Cheetah 4LP family drive
Cheetah 4LP Product Manual, Rev. B 7
3.1 Standard features
The Cheetah 4LP famil y has the following stand ard feat ures:
• Integrated SCSI control ler
• Single-ended or differential SCSI drivers and receivers
• 8-bit and 16-bit I/O data bus models availabl e
• Asynchronous and synchronous data transfer protocol
• Firmware downloadable via SCSI interfa ce
• Selectable sector size from 180 to 4,096 bytes/sect or
• Programmable drive capacity
• Programmabl e sector reallocation scheme
• Flawed sector reallocation at format time
• Programmable auto write and read reallocation
• Reallocation of defects on comm and (Po st format )
• Reed-Solomon error correcting code can correct up to 64-bit error
• Sealed head/disc assembly
• No preventative maintenance or adjust men t required
• Dedicated laser textured head landing zone
• Embedded servo data rather than a separate servo data surfa ce
• Self diagnostics performed at power o n
• 1:1 interleave
• Zoned Bit Recording (ZBR)
• Vertical, horizontal, or top-down mounting
• Dynamic spindle brake
• Active IC terminators enabled by jumpers (“N” and “W” models only)
• 442 Kbyte data buffer (2 Mbyte optional)
• Hot Plug compatibility (Sect ion 9.6.4 .3 lists proper host connector need ed) for “WC” and “DC” model drives
• SCAM (SCSI Configured AutoMagically) plug-n-play level 1 compliant as shipped. Level 2 is a factory
installed option.
3.2 Media characteristics
The media used on the drive has a diameter of approximately 3.5 inches (86 mm). The aluminum substrate is
coated with a thin film magnet ic m ateri al, overcoate d with a propriet ary prot ective layer f or improved durability
and environmental protectio n.
3.3 Performa nce
• Supports industry standard Fast-20 SC SI inte rface (also called “Ult ra SCS I ”)
• Programmable multi-segmentable cache buffer
• 10,033 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 spinnin g )
3.4 Reliability
• 1,000,000 hour MT BF
• LSI circuitry
• Balanced low mass rotary voice coil actuator
• Incorporates industry -standard Self-Mo nito ring, Analysis and Reporting Technology (S.M.A.R.T.)
• Incorporates Seek To Improve Rel iabil ity algori thm (STIR)
• 5-year warranty
• Dithering
8 Cheetah 4LP Product Manual, Rev. B
3.5 Unformatted and formatted cap aci ties
Formatted ca pacity depends on the number of spare reallocati on sectors reserved and the number o f bytes
per sector. T he followin g table shows the standard OEM model capaci ties:
Formatted [1]
Data Block Size
512 Byte/Sector Unformatted
4.550 GB [2] 5.591 GB
Notes.
[1] Sector size selecta ble at format time. Users having the n ecessary equipment may m odify the da ta block
size before issuing a format command and obtain different fo rmatted capacities than those list ed. User
available capacity depends on spare reallocati on scheme selected. S ee Mo de Select Com ma nd and Fo rmat Command in the
SCSI Interface Product Manual
, P/N 77738479.
[2] Formatted with a regional sparing scheme. Each region contains 12 cylinders. Each region has 108 spare
sectors.
3.6 Program m ab le dr ive c ap aci t y
Using the Mode Select comman d, the drive can change its capacity to something less than maxim um. See
Table 5.2.1-13 in the
SCSI Interface Product Manual
, P/N 77738479, Rev. G or later. Re fer to the Parameter
list block descriptor, number of blocks field. A value of zero in the number of blocks field indicates that the drive
cannot 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 accesso rie s
OEM standard drives are shipped with the
Cheetah 4LP Installat ion Guide
, P/N 83329110 (unless otherwise
specified). The f actory also shi ps with the drive a small bag of the two jump er plug types used for the J5, J6,
and J2 option select jumper headers.
3.8 Options (factory instal led )
All customer requested opt ions are incorporated during production o r packaged at the manufacturing facilit y
before shipping. Some of the options availabl e are (not an exhausti ve list of possible options):
• Other capacities can be ordered depending on sparing scheme and sector size requested.
• Black plastic front panel. Other panel colors may be special-ordered. Panel has a green, rectangular LED
drive activity indicator lens. The indicator glows when the drive is selected.
• Single-unit shipping pack. The drive is normally shipped in bulk packaging t o provide maximum protection
against transit damage. Units shipped individually require additional protection as provided by the single unit
shipping pack. Users planning single unit distribution should specif y this opt ion.
• The
Cheetah 4LP Installation Guide
, P/N 83329110 is usually included with each standard OEM drive
shipped, but extra copies may be ordered.
• 2 Mbyte cache memory option. Standard cache memory is 442 Kbytes.
• Level 2 SCAM compliance.
3.9 Accessories (user installe d)
The following accessories are available. All accessories may be installed in the field.
• Front panel kit (with green rectangular LE D lens), P/N 734971 51
• Single-unit shipping pack
Cheetah 4LP Installat ion Gu ide
•
, P/N 83329110
Cheetah 4LP Product Manual, Rev. B 9
4.0 Performance characteristics
4.1 Internal drive characteristic s (transp arent to user )
Drive capacity 5,591 Gbyte (unformatted) (rounded-off values)
Read/write heads 8
Bytes/track 115,078 Bytes (average) (rounded-off values)
Bytes/surface 751.0 Mbytes (unformatted) (rounded-off values)
Tracks/surface (total) 6,526 Tracks (user accessible)
Tracks/inch 6,932 TPI
Bits/inch (minim um ) 94,001 BPI
Bits/inch (maximum) 135,401 BPI
Internal data rate 122-177 Mbits/sec (variable with zone)
Disc rotational speed 10,033 ±0.5% r/min
Average rotational lat ency 2.99 msec
4.2 SCSI performance charac teristics (vis ible to user)*
The values given in Secti on 4.2.1 apply to all models of the Cheetah 4L P family unless otherwise specified.
Refer to Section 9.10 and to the
4.2.1 Access time [6]
SCSI Interface Product Ma nual,
P/N 77738479 for additional timing detail s.
Including controller overhead
(without disconnect) [2] [3]
Read Write
msec
Average (typical) [2] 7.7 8.7
Single track (typical) [2] 0.98 1.24
Full stroke (typical) [2] 18.2 19.2
4.2.2 Format command executio n time (minutes) [ 1]
ST34501
Maximum (with verify ) < 1 hours
Maximum (no verify) < 0.6 hour
4.2.3 Generalized performance characteristics
Minimum sector interlea ve 1 to 1
Data buffer transfer rate to/from disc media (one 512-byte sector)—variable with zone/cylinder:
Minimum [3] 122 Mbits/sec
Maximum [3] 177 Mbits/sec
Data buffer transfer rate to/from disc media (< 1 track):
Minimum [3] TBD Mbytes/sec divided by (interleave factor)
Average [3 ] TBD M byt es/sec divided by (interleave factor)
Maximum [3] TBD M byt es/sec divided by (interleave factor)
*[ ] All notes for Section 4.2 are listed at end of Section 4.2. 3.
10 Cheetah 4LP Product Manual, Rev. B
SCSI interface data transfer rate (asynchronous) [4]:
Maximum instantane ous (16 bit wide) 10.0 Mbytes/sec [5]
Maximum instantane ous (8 bit wide) 5.0 Mbytes/sec [5]
Synchronous transfer rate for SCSI Fast-20 (Ultra SCSI):
8 bit data bus (N model) 2.5 to 20 Mbytes/sec
16 bit data bus (W/WC/WD/DC models) 5.0 to 40 Mbytes/sec
Sect or Si zes
Default
Variabl e
Read/write consecutive sectors on a track Yes
Flaw reallocation perform ance impact :
For flaws reallocated at format time Negligible
For flaws reallocated using the spare sectors per cylinder reallocation scheme 5.98 msec (minimum)
Overhead time for head switch (512-byte sectors) in sequential mode 0.798 msec
Overhead time for one track region switch in sequential mode 1.064 msec (typical)
Average rotational latency 2.99 msec
512-byte user data blocks
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.
17.94 msec (maximum )
Notes for Section 4.2.
[1] Execution time measured from receipt of the last Byte of the Command Descriptor B lock (CDB) to the
request for a status byte transfer to the initiator (excluding connect/discon nect).
[2] Typical access times are measured under nominal conditions of temperature, voltage, and horizontal ori-
entation as measured on a representative samp le of drives.
[3] Assumes no errors and no sector has been relocated.
[4] Rate measured from the start of the first sector transfer to or from the host.
[5] Assumes system abi lity to support th e rates listed and no cable loss.
[6] Access time = controller overhead + average seek time
Access to data = controller overhead + average seek time + latency time
4.3 Start/stop time
After DC power at nominal voltage has been applied, the drive becomes ready within 30 seconds if the Motor
Start Option is disabled (i.e., the motor starts as soo n as the power has been applied). If a recoverable error
condition is detected during the start sequence, th e drive executes a recovery procedure which may cause the
time to become ready to exceed 30 seconds. During spin up to ready time the drive responds to some commands over the SCSI interface. Stop time is less than 30 seconds from removal of DC power.
If the Motor Start Opt ion is enabled, the int ernal con troller ac cepts the comm ands listed in the
Product Manu al
been received the drive becomes ready for normal operations within 30 seconds typically (excluding an error
recovery procedure). The Motor Start comm and can also be used to command the drive to stop the spindle
(see the
SCSI Interface Product Manual
less than 3 seconds after DC p ower has been applied. Af ter the Motor St art command has
, P/N 77738479).
SCSI Int erf ac e
There is no power control switch on the drive.
4.4 Prefetch/multi-se gmen ted cach e contro l
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 t he Mode Sele ct command with the pro per values in the appli cable byt es in Mode Page 08h (see th e
SCSI Interface Prod uct Man-
Cheetah 4LP Product Manual, Rev. B 11
ual
, P/N 77738479. Prefetch and cache operation are indepe ndent features from the standpoint that each is
enabled and disabled independent ly via the M ode S el ect comm and. 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 Table 9.
4.5 Cache operation
In general, 442 Kbytes of the 512 K bytes of physical buffer space in the drive (1,850 Kbytes of the 2. 0 megabytes on units with this option) can be used as storage space for cache operations. The buffer can be divided
into logical segment s (Mode Select Page 08h , byte 13) from which data is read and to which data i s written.
The drive maintains a table of logi cal block disk medium ad dresses 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 the
Product Manual,
(if it is there), before any disc ac cess is initiated. If cache operati on is not enabled, t he buffer (still segmente d
with required number of segments) is still used, but only as circular buffer segments during disc med ium read
operations (disregarding Prefet ch operation for th e moment). Tha t is, the drive does not check in the buffer
segments for the requested read dat a, but goes directl y to the mediu m to retrieve it. The retrieved data m erely
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
Manual
.
P/N 77738479), data requested by the host with a Read command is retrieved from the buffer
SCSI Interface Product
SCSI Int erface
The following is a simplified description of a read operation with cache operation enabl ed:
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 subsequen t contiguous LB s that are already in
the cache. This data may be in multiple seg men ts.
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 sp e cificat ion m entioned above.
3. If the prefetch feature is enabled, refer to Section 4.5.2 for operat ion 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 f rom the disc and transfers them into a segment , and from there t o
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 operat ion from this point.
Each buffer segm ent is actuall y a sel f-contained circular storage (wra p-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). Th e number of segment s may be selected using the Mo de Select comm and, but the size
can not be directly selected. Size is selected only as a by-product of selecting the segment num ber specification. The size in Kbytes of each segment is not reported by the Mode Sense command page 08h, bytes 14 and
15. These bytes read OxFFFF, regardless of the number of segments sett ing. If a size specification is sent by
the host in a Mode Sel ect command (byte s 14 and 15) no new segme nt size is set up by the drive, a nd if the
“STRICT” bit in Mode page 00h (byte 2, bit 1) is set to one, the drive responds as i t does for any attempt to
change unchangeable parameters ( see the
any integer number of segments from 1 to 16.
SCSI Interf ace Product Manual).
The drive support s operation of
4.5.1 Caching write data
Write caching is a write operat ion b y the drive that ma kes use of a dri ve buffer storage area wh ere the dat a to
be written to the medium is stored in one or more segment s while th e drive perform s the write com man d.
Write caching is enabled along with read caching. For write caching , the same buffer space a nd segm ent atio n
is used as set up for read functions. The buffer segmentation scheme is set up or changed independently, hav-
12 Cheetah 4LP Product Manual, Rev. B
ing nothing to do with whether or not read and write caching is enable d or disabled. When a write comma nd is
issued, 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 comma nd. If there are, the respect ive cache segments are cleared. Th e
new data is cached for subsequent Read commands.
If the number of write data logical blocks exceeds the size of the segment being writ ten 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 .
Table 9 shows Mode default settings fo r the drive.
4.5.2 Prefetch operation
If the Prefetch feat ure is ena bled, data in co ntiguous log ical bl o cks on the disc imme diat ely beyon d that wh ich
was requested by a Read comm and can be ret rieved and stored in the b uffer for immediat e transfer from the
buffer to the host on subsequent Read commands that request those logi cal blocks (this is true even if “cache”
operation is disabled). Though the pref etch operati on uses the buffer as a “cache,” finding the requested dat a
in the buffer is a prefetch “hit,” not a “cache” operation “hit.” Prefetch is enabled using Mode Select page 08h,
byte 12, bit 5 (Disabl e Read Ahead - D RA bit). DRA bit = 0 enabl es prefetch. Since data that is prefetched
replaces data already in some buffer segment(s), the host can limit the amou nt of prefetch data to optimize
system performance. The max prefetch field (bytes 8 and 9) limits t he 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 paramete rs page 08h.
Whenever prefetch (read look-ahea d) is enab led (enabled by DRA = 0), it opera tes un der the cont rol 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” wi ll not likely occur. If the host is not using software interleave, a nd 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 4LP Product Manual, Rev. B 13
5.0 Reliability specifications
The following reliabilit y specif ications assume correct host/drive operational interface, including all interface
timings, power supply voltages, environment al requi remen ts and drive mounting constraint s (see Sectio n 8.4).
Seek errors
Less than ten in 10
Read error rates [1]
Unrecovered data Less than 1 sector in 10
Miscorrected data Less than 1 sector in 10
MTBF 1,000,000
Service life 5 years
Preventive maintenance None required
Note.
[1] Error rate specified with automat ic retries and data correction wit h ECC enabled an d all flaws reallocated.
5.1 Error rates
The error rates stated in this specification assume the following:
• The drive is operated per this specifica tion using DC power as defined in this manua l (see Sectio n 6.2).
• The drive has been formatted with the SCSI format commands.
• Errors caused by media defects o r host system fail ures are excluded from error rat e computa tion s. Refer to
Section 3.2, “Media Characteristics.”
8
seeks
14
bits transferred (OEM default settings)
21
bits transferred (OEM default settings)
5.1.1 Environmental in te rferen c e
When evaluating s ystems operation under conditions of Electromag netic In terference (EM I), the perform ance
of the drive within the system is considered acceptable if the drive does not generat e an unrecoverable c on dition.
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 determinat ion or measurem ent 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, environment al interference, or equipmen t m alfunction.
Therefore, write errors are not predictable as a function of the number of bits passed.
If a write error un recove rable occurs because of a n equipment malfunct ion in the drive, the error is classifie d
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 po sition the heads t o the addressed track. There will be no
more than ten recoverable seek errors in 10
8
physical seek operations. After det ectin g an ini tia l seek error, the
drive automatically perform s an error recovery process. If the error recovery process fails, a seek positioning
error (15h) is reported with a Mediu m error (3h) or Hardwa re error (4h) report ed in the Sense Key. This is an
unrecoverable seek error. Unrecoverable seek errors are classified a s failures for M TBF calculat ions. Ref er to
Section 5.1.1.2 of the
SCSI Interface Product Manual,
P/N 77738479, for Request Sense information.
14 Cheetah 4LP Product Manual, Rev. B
5.2 Reliability an d servic e
You can enhance the reli ability of Cheetah 4LP disc drives by ensuring that the drive receives adequate cooling. Section 6.0 provides tem perature m easurements and ot her information t hat may be used to enh ance the
service life of the drive. Section 8.3.1 provides recommended air-flow informat ion.
5.2.1 Mean time between failure
The production disc drive achieves an MTBF of 1,000,000 hours when operated in an environment that
ensures that the case temperatures specifi ed in column 2 of Table 3 are not exceeded (see Section 6.4.1).
Short-term excursions up to the specificat ion limits of the operating environm ent (given in Table 3, column 1)
will not affect MTBF perform ance. Continual or sustained operat ion at case temperatures above the values
shown in Table 3, column 2, may degrade product reliability.
The following expression defines MTBF:
Estimated power-on operating hours in the perio d
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 will have accumulated at least nine months of operation. Data will b e calculated on a rolling average base for a minimum period of six months.
Drive failure means any stoppage or substandard performa nce caused by drive malfunct ion.
5.2.2 Preventive maintenance
No routine scheduled preventive mainten ance is required.
5.2.3 Service life
The drive has a useful service life of five years. Depot repair o r replacem ent of major parts i s permi tted durin g
the lifetime ( see Sect ion 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 recommen ded, 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 recomm ende d 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.
5.2.6 Hot plugging Cheetah 4LP disc dri ves
During power-up and power-down periods, the hot SC SI connect/disconnect capability on Cheet ah 4LP SCSI
disc units will produce no glitches and/or any corruptions on an active SCS I bus.
Note. It is the responsibility of the systems int egrat or to assu re that n o tempe ra ture, ene rgy, voltage hazard,
or ESD potential is presented during the hot connect/disconnect operati on.
1. All I/O processes for the SCSI device being inserted or removed shall be quiescent. All other SCSI devices
on the bus shall have receivers that conform to the SCSI-3 standard.
2. A device being inserted shall make its power grou nd and logic ground connection at least 1 millisecond
prior to the connection of any device connecto r contact to the bus. The ground connect ions shall be maintained during and after the connection of the device to the bus.
3. A device being removed shall maintain its power ground and logic ground prior to, during, and for at least 1
msec after the disconnection of any device connector contact from the bus.
Cheetah 4LP Product Manual, Rev. B 15
4. The SCSI device being removed or inserted shall employ transceivers that conform to the requirements for
glitch-free powe r-on/off in th e S C S I-3 standard. Th e SCSI device shall maintain the high -impedance state
at the device connector contacts during a power cycle until the transceiver is enabled.
5. The power to the electronics and mechanics of the device may be simultaneously switched with the bus
contacts if the power distribution system i s able to m aintain adequ ate power stabilit y to ot her d e vi ces during the transition and the grounding requireme nts in items 2 and 3 are met.
6. The SCSI bus termination shall be external to the device being inserted or removed.
7. Connector J2 must be configured so there is no connection between the drive and TRMPW R signal on
SCSI bus. Removing all jumpers will accom plish this.
8. The disc drive m otor must come to a com plete st op prior t o changing the plane of operation. This time is
required to insure data integrity.
Note. Hot-plug drives are not designed for simultaneous power discon nection and ph ysical removal .
5.2.7 S.M.A.R.T.
S.M.A.R.T. is an a cronym for Self-Moni toring Analysis and Re porting Technology. This technology is int ended
to recognize conditions that i ndicate a d rive fail ure a nd i s desi gned to provid e sufficient wa rning of a f ailure to
allow data back-up before an actual failure oc curs.
Note. The firmware will monitor specific attributes for degradation over time but cannot predict instantaneous
drive failures.
Each attribute ha s been sele cted to m oni tor a spe cific set of fa ilure con dit ions in the o perat ing pe rform ance of
the drive, and the thresholds are optimized to minim ize “false” and “fai led” predict ions.
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 M ode Page” (1Ch). The DE XCPT bi t is used to enable or disab le 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 perform s n o rmal read/writ e o perat ions. Whe n t he PERF b it is set, t he drive is conside re d to be i n
“On-line Mode Only” and will not perform off-line function s.
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 inte rrup 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. interruptio ns occur. As described above, forcing S.M.A.R.T by the RTZ comm and will reset the timer.
Performa nce imp a ct
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 para meters once every two h ours subject t o an idle perio d on the
SCSI bus. The process of measuring off-line attribute dat a 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 200 milliseconds
Reporting control
Reporting is controlled in the “Inform ational Ex ceptions Control Page” (1Ch). Subject to the reporting method,
the firmware will issue to the “host” an 01-5D00 sense code. The error code is preserved through bus resets
and power cycles.
16 Cheetah 4LP Product Manual, Rev. B
Determining rate
S.M.A.R.T. moni tors the rate at which errors occur and signals a p redicti ve f ailure if the rat e of degraded error
rate increases to an unacceptable le vel. To det ermine rat e, error events are logged and com pared to the number of total operations for a given attribut e. The interval d efines the number o f operations over w hich to me asure 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 Count er.
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 count ers are reset and the process starts over.
Predictive failures
S.M.A.R.T. signals predi ctive f ail ures when the drive is pe rform ing unaccept ably for a p eri od of tim e. The firm ware 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 (no t 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 attribut e.
5.2.8 Product warranty
Beginning on the date of shipment to customer and continuing for a period of five years, Seagate warrants that
each product (including components and subassemblies) or spare part that fails to function properly under normal use due to defect in materials on workmanship or due to nonconformance to the applicable specifications
will be repaired or replaced, a t Seagate’s opt ion an d at no charge to custom er, if returned by customer at customer’s exp ense to Seagate’s design ated facility in accordance wi th Seagate’s Warranty Procedure. Seagate
will pay for transporting the repair or replacem ent item to customer. F or more detailed warranty information
refer to the Standard Terms and Conditions of Purchase for Seagate products.
Shippi ng
When transporting or shippi ng a drive, a Seagate appro ved container must be used. Keep your origin al box.
They are easily identified by the Seagate Ap proved Package label. Shipping a drive in a non-approved container voids the drive warranty.
Seagate repair centers m ay refuse receipt of components i mprop erly packaged or o bviously damaged in transit. Contact your Autho rized S eagate Di stribut or to purchase a ddit ional boxes. Se agat e recommen ds shippin g
by an air-ride carrier experienced in handling computer equipment.
Product repair and return inform ati on
Seagate customer service centers are the only facilities authorize d to service Seagate drives. Seagate does
not sanction any third-party repair facilities. Any unautho rized repair or tampering with the factory-seal voids
the warranty.
Cheetah 4LP Product Manual, Rev. B 17
6.0 Physical/electrical specifications
This section provides information relating to the physical and electrical characteristics of the Cheetah 4LP
drives.
6.1 AC power requ irements
None.
6.2 DC power requ irements
The voltage and current requirements for a single drive are shown in the following table. Values indicated apply
at the drive power connector. The single ended power requirements includes the internal d isc drive SCS I I/O
termination. The table shows current values in Amperes.
Table 2: DC power requirements
Notes
ST34501N/W/WC
Single-ended
ST34501WD/DC
Differential
Voltage +5 V [8] +12 V +5 V [8] +12 V
Regulation [5] ±5% ±5%[2] ± 5% ±5%[2]
Maximum operating current DC3σ [1] 0. 9 0 0.94 1 .09 0.94
Average idle current DCX
[1] [11] 0. 64 0.73 0.72 0. 7 3
Maximum starting current
(peak DC) DC3σ
(peak AC) AC3σ
[3] [6]
[3]
0.88
—
2.2
3.65
0.89
—
2.2
3.65
Delayed motor start (max) DC3σ [1] [4] 0.81 0.08 0 .72 0.08
Peak operating current
Typical DCX
Maximum D C3σ
Maximum (Pe ak) DC3σ
[1] [7]
[1]
0.85
0.9
1.0
0.89
0.94
1.98
1.05
1.09
—
0.89
0.94
1.98
Track following at
OD DCX
ID DCX
[1]
[1]
0.8
0.78
0.73
0.72
0.89
—
0.73
0.72
Read Track
OD DC3σ
AC3σ
Seeking (typical) DCX
Maximum DC3σ
Maximum (peak) AC3σ
[1] [10] 0.95
1.07
0.84
[1] [9]
[1]
0.88
0.93
0.76
1.0
1.11
1.20
2.02
1.26
2.00
0.89
0.93
1.58
0.76
1.0
1.11
1.20
2.02
[1] Measured with average reading DC amm eter. Instantaneous +12V current peaks will exceed these val-
ues.
[2] A –10% tolerance is permissible during initial start of spindle, and mu st return to ±5% before 10,000 rpm
is reached. The ±5% must be mai ntained after the drive signifies th at its power-up sequence has been
completed and that the drive is able to accept selection by the host initiator.
[3] See +12V current profile in Figure 3.
[4] This condition occurs when the Motor Start Option is enabled and the drive has not yet received a Start
Motor command .
[5] See Section 6.2.1, “Conducted No ise Im munit y.” Specified voltage t olera nce is inclusive of ri pple, noise,
and transient response.
[6] At power-up, the motor current regulator limits the 12 volt current to an average value of less than 2.2
amperes, although inst antaneous peaks may exceed this value. These pe aks should measure 5 msec
duration or less.
[7] Operating condition i s defined as a third-st roke seek at OD a nd Read One track. A comm and is is sued
every (0.048 seconds on Wide and SCA drives).
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