seagate ST136475 Installation guide
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Barracuda 36 Family:
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ST136475LW/LC
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Product Manual, Volume 1
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Barracuda 36 Family:
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ST136475LW/LC
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Product Manual, Volume 1
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© 1997-2000 Seagate Technology, LLC All rights reserved
Publication number: 77767528, Rev . C
August 2000
Seagate, Seagate Technology, and the Seagate logo are re gistered trademar ks of Seagate Technology,
LLC. Barracuda, SeaFAX, SeaFONE, SeaBOARD, and SeaTDD are either trademarks or registered
trademarks of Seagate Technology, LLC, or one of its subsidiaries. All other trademarks or registered
trademarks are the property of their respective owners.
Seagate reser ves the right to change, without notice, product offerings or spe cifications. No part of this
publication may be reproduced in any form without written permission of Seagate Technology, LLC.
Revision status summary sheet
Revision Date Writer/Engineer Sheets Affected
Rev. A 04/20/99 D. Ashby/P. Kusbel 1/1, v thru viii, 1-82
Rev. B 09/02/99 D. Ashby/P. Kusbel 25
Rev. C 08/22/2000 K. Schweiss/B. Reynolds ii, 1, 36, 42, 69-71, and backcover
Notice.
Product Manual 77767528 is Volume 1 of a two volume document with the SCSI Interface information in
the Volume 2 SCSI Interface Product Manual, part number 77738479.
If the SCSI Interface information is needed the Volume 2 Interface Manual should be ordered,
part number 77738479.
Barracuda 36 Product Manual, Rev. C vii
Table of Contents
1.0 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2.0 Applicable standards and reference documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Standards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1 Electromagnetic compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.2 Electromagnetic susceptibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.2 Electromagnetic compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3 Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.0 General description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Standard features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Media characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.4 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.5 Unformatted and formatted capacities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.6 Programmable drive capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.7 Factory installed accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.8 Options (factory installed). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 characteristics (visible to user) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.1 Access time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.2 Format command execution time (minutes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.3 Generalized performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.3 Start/stop time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.4 Prefetch/multi-segmented cache control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.5 Cache operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.5.1 Caching write data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.5.2 Prefetch operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.0 Reliability specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
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 Barracuda 36 disc drives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.7 S .M.A.R.T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2.8 Product warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.0 Physical/electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.1 AC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.2 DC power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.2.1 Conducted noise immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.2.2 Power sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.2.3 Current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.3 Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6.4 Environmental limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6.4.1 Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6.4.2 Relative humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
viii Barracuda 36 Product Manual, Rev. C
6.4.3 Effective altitude (sea level). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
6.4.4 Shock and vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
6.4.5 Air cleanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
6.4.6 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
6.4.7 Electromagnetic susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
6.5 Mechanical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 8
7.0 Defect and error management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
7.1 Drive internal defects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
7.2 Drive error recovery procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
7.3 SCSI systems errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
8.0 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
8.1 Drive ID/option select header . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
8.1.1 Function description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
8.2 Drive orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
8.3 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
8.3.1 Air flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
8.4 Drive mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
8.5 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
9.0 Interface requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
9.1 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
9.2 SCSI interface messages supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
9.3 SCSI interface commands supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
9.3.1 Inquiry Vital Product data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
9.3.2 Mode Sense data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
9.4 SCSI bus conditions and miscellaneous features supported . . . . . . . . . . . . . . . . . . . . . . . . .49
9.5 Synchronous data transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
9.5.1 Synchronous data transfer periods supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
9.5.2 REQ/ACK offset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
9.6 Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
9.6.1 DC cable and connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
9.6.2 SCSI interface physical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
9.6.3 SCSI interface cable requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
9.6.4 Mating connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
9.7 Electrical description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
9.7.1 Multimode—SE or LVD alternative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
9.8 Terminator requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
9.9 Terminator power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
9.10 Disc drive SCSI timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
10.0 Seagate Technology support services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
Appendix A. Sense keys and additional sense codes supported . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
Barracuda 36 Product Manual, Rev. C ix
List of Figures
Figure 1. Barracuda 36 family drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Barracuda 36 family drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 3a. Typical Barracuda 36 family drive +12 V current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 3b. Typical Barracuda 36 family drive +5 V current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 3c. DC current and power vs. input/output operations per second (LVD only) . . . . . . . . . . . . . . 22
Figure 3d. DC current and power vs. input/output operations per second (SE only) . . . . . . . . . . . . . . . 22
Figure 4. Locations of PCBA components listed in Table 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 5. Recommended mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 6a. Mounting configuration dim ens io ns for “LW” model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 6b. Mounting configuration dim ens io ns for “LC” model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 7a. Barracuda 36 family drive ID select for models “LW” and “LC” . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 7b. Barracuda 36 family drive ID select header J5 for “LW” model (J5 Pins 1–12) . . . . . . . . . . . 35
Figure 7c. Barracuda 36 family drive option select header for both “LC” and “LW” models . . . . . . . . . . 36
Figure 8. Air flow (suggested) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Figure 9a. Model “LW” drive physical interface (68 pin J1 SCSI I/O connector) . . . . . . . . . . . . . . . . . . . 52
Figure 9b. Model “LC” drive physical interface (80 pin J1 SCSI I/O connector and
DC power connector) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Figure 10. SCSI daisy chain interface cabling for “LW” model drives . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Figure 11a. Nonshielded 68 pin SCSI device connector used on “LW” models . . . . . . . . . . . . . . . . . . . . 56
Figure 11b. Nonshielded 80 pin SCSI “SCA-2” connector, used on “WC” and “LC” models. . . . . . . . . . . 57
Figure 12. LVD output signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Figure 13. Typical SE-LVD alternative transmitter receiver circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Barracuda 36 Product Manual, Rev. C 1
1.0 Scope
This manual describes the Seagate Technology®, LLC , Barracuda 36™ disc drives.
Barracuda 36 drives support the small computer system interface (SCSI) as described in the ANSI SCSI,
SCSI-2, and SCSI-3 ( Fast-20 and Fast-40) interface specific ations to the extent descr ibed in this manual. T he
SCSI Interface Product Manual (pa rt number 7773847 9) describes general SC SI interface characteristics o f
this and other families of Seagate drives.
From this point on in this produc t manual the reference to Barracud a 36 models is referred to as “the dr ive”
(unless references to individual models are necessary).
*
*Model “LW” version with 68 pin SCSI I/O connector
Figure 1. Barracuda 36 family drive
Barracuda 36 Product Manual, Rev. C 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 i ts host equip ment to provide adequ ate power and environment i n order to achieve optimum performance and compli ance with applicable industry and governm ental regulations. Special attention
must be given in the areas of safety, power distribution, shielding, audible noise control, and temperature regulation. In particular, the drive must be secur e ly mo unte d i n o rd er to guara ntee the s pec if ied per for ma nc e char acteristics. Mounting by bottom holes must meet the requirements of Section 8.4.
2.1 Standards
The Barracuda 36 family compli es with S eaga te s tan dar ds a s n oted in the appropriate se cti ons o f thi s Manual
and the Seagate SCSI Interface Product Manual, part number 77738479 (Vol. 2).
The Barracuda 36 disc drive is a UL recognized component per UL1950, CSA certified to CAN/CSA C22.2 No.
950-95, and VDE certified to VDE 0805 and EN60950.
2.1.1 Electromagnetic compatibility
The drive, as delivered, is designed for system integration and installation into a suitable enclosure prior to use.
As such the drive is suppli ed as a subassembly and is not su bject to Subpar t 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 req uirements in their syst em. Shielded I/O
cables may be required if the e nclosure does not provide ad equate sh ielding. If the I/O c ables are externa l to
the enclosure, shielded cables should be used, with the shields grounded to the enclosure and to the host controller.
2.1.2 Electromagnetic susceptibility
As a component assembly, the drive is not required to meet any susceptibility per formance requ irements. It is
the responsibility of tho se integrating the dr ive within their sy stem s to perform thos e tests req uired and design
their system to ensu re that equipment operating in the sam e system as the drive or external to the s ystem
does not adversely affect the performance of the drive. See Section 5.1.1 and T able 2, DC power requirements.
2.2 Electromagnetic compliance
Seagate uses an independ ent laboratory to co nfirm compliance to the directives/standard(s) for CE Mark ing
and C-Tick Marking. The drive was tested in a representative system for typical applications. The selected system represents the most popular characteristics for test platforms. The system configurations include:
• typical current use microprocessor
• 3.5-inch floppy disc drive
• Keyboard
• Monitor/display
• Printer
• External modem
• Mouse
Although the test system wi th this Seag ate mode l co mpl ie s to the dire cti ves/standa rd(s ), we cann ot gua rante e
that all systems will comply. The computer manufacturer or system i ntegrator shall confir m EMC complianc e
and provide CE Marking and C-Tick Marking for their product.
Electromagnetic compliance for the European Union
If this model has the CE Marki ng it complies with the European Union requirem ents of the Electromagnetic
Compatibility Direc tive 89/336/EEC o f 03 May 1989 as ame nded by Direct ive 92/31/EE C of 28 Ap r il 1992 an d
Directive 93/68/EEC of 22 July 1993.
4 Barracuda 36 Product Manual, Rev. C
Australian C-Tick
If this model has the C-Tick Markin g it complies with the Australia/New Zea land Standard A S/NZS3548 199 5
and meets the Electro magnetic Compatibility (EMC) Framework requirements of Australia’s Spectrum Management Agency (SMA).
2.3 Reference documents
Barracuda 36 Installation Guide Seagate P/N 77767529
SCSI Interface Product Manual Seagate P/N 77738479
ANSI small computer system interface (SCSI) document numbers:
X3.131-1994 SCSI-2
T10/1302D SPI-3
X3T10/1143D EPI
SFF-8046 Specification for 80-pin connector for SCSI disk drives
SCA-2 EIA Specification ANSI/EIA
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.
Barracuda 36 Product Manual, Rev. C 5
3.0 General description
Barracuda 36 drives combine magnetoresistive (MR) heads, partial response/maximum likelihood (PRML)
read channel electronics, embedded servo technology , and a SCSI-3 (Fast-20 and Fast-40) interface to provide
high performance, high capaci ty data storage for a variety of syste ms incl uding en ginee ring work statio ns, network servers, mainframes, and supercomputers.
Fast-20 and Fast-40 (also known as Ultra-1 SCSI and Ultra-2 SCSI, respectively) are negotiated transfer rates.
These transfer rates will occur only if your host adapter als o supports these dat a t ransfer rates. This drive also
operates at SCSI-1 and SCSI-2 data transfer rates for backward compatibility with non-Fast-20/Fast-40 capable SCSI host adapters.
Table 1 lists the features that differentiate the various Barracuda 36 models.
Table 1: Drive model number vs. differentiating features
Model number
Number
of heads I/O circuit type [1]
Number of I/O
connector pins
Number of I/O
data bus bits
ST136475LW 20 multimode (SE/LVD) 68 16
ST136475LC 20 multimode (SE/LVD) 80 16
[1] See Section 9.6 for details and definitions.
The drive records and recovers data on 3.5-inch (86 mm) non-removeable discs.
The drive suppor ts the Small Computer System Interface (SCSI) as descr ibed in the ANSI SCSI-2/SCSI-3
SPI-2 interface specifications to the extent described in this manual (volume 1), which defines the product performance character is ti cs of th e Barracuda 36 family of drives, and the SCSI Inter face Produc t Manual (volume
2), part number 77738479, whi ch describes the general interface characteri stics 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 disa ssemble the HDA and do not attempt to service items in the seal ed enclo sure (h eads, med ia, actuat or, etc.) as this
requires special facilities. The drive contains no replaceable parts. Opening the HDA voids your warranty.
Barracuda 36 dri ves use a dedic ated landing zone at the innermost radius of the med ia t o el imi na te th e pos s ibility of destroying or degrading da ta by landing in the d ata zone. The drive automa tically 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 ha ndl ing . T he shi ppi ng lock au toma tic al ly di se nga ges whe n power is applied to the drive and
the head load process begins.
Barracuda 36 drives decode track 0 locatio n data from the servo data embedded on each surface to eliminat e
mechanical transducer adjustments and related reliability concerns.
A high-performance actuator assembly with a low-inertia, balanced, patented, straight-arm design provides
excellent performance with minimal power dissipation.
6 Barracuda 36 Product Manual, Rev. C
Figure 2. Barracuda 36 family drive
Barracuda 36 Product Manual, Rev. C 7
3.1 Standard features
The Barracuda 36 family has the following standard features:
• Integrated SCSI controller
• Multimode SCSI single-ended or low voltage differential drivers and receivers
• 16 bit I/O data bus
• Asynchronous and synchronous data transfer protocol
• Firmware downloadable via SCSI interface
• Selectable sector sizes from 512 to 2,048 bytes/sector in multiples of 2 bytes/sector
• Programmable drive capacity
• 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 laser textured head landing zone
• Embedded servo data rather than a separate servo data surface
• Self diagnostics performed when power is applied to the drive
• 1:1 Interleave
• Zoned bit recording (ZBR)
• Vertical, horizontal, or top down mounting
• Dynamic spindle brake
• 1 Mbyte, or optional 4 Mbyte data buffer
• Hot plug compatibility (section 9.6.4.2 lists proper host connector needed) for “LC” model drives
• SCAM (SCSI Configured AutoMagically) plug-n-play level 2 compliant, factory set to level 1 (not user select-
able)
• Low audible noise for office environment
• Low power consumption
3.2 Media characteristics
The media used on the dr ive has a di ameter of a pproximately 3 .5 in ches (8 6 mm). The alumi num substrat e is
coated with a thin film magneti c mat eria l, overcoated with a propr iet ar y prote ctive layer for improved durability
and environmental protection.
3.3 Performance
• Suppor ts industry standard Fast-20 and Fast-40 SCSI inter faces (also called “Ultra-1 SCSI” and “Ultra-2
SCSI,” respectively)
• Programmable multi-segmentable cache buffer (see Section 4.4)
• 7200 RPM spindle. Average latency = 4.17 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 industry-standard Self-Monitoring, Analysis and Reporting Technology (S.M.A.R.T.)
• Incorporates Seek To Improve Reliability algorithm (STIR)
• 5-year warranty
8 Barracuda 36 Product Manual, Rev. C
3.5 Unformatted and 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 standar d OEM model rea d capacities da ta. Total LBAs = read cap acity
data shown below +1.
Formatted capacity
data block size 512 bytes/sector [1]
ST136475 43D671Fh (36 GB) [2]
Notes.
[1] Sector size se lectable at format time. Users having the necessar y equipmen t may modify the data block
size before issuing a format co mmand and obtain different formatted capa cities 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 spa re reallocation scheme se lected. The number of data tracks per
sparing zone and the number of alte rnate sectors (LBAs ) per sparing zone can be deter mined by using
the Mode Sense command and reading Mode Page 03h. Total LBAs(h) x 200(h) = total byte capacity.
3.6 Programmable drive capacity
Using the Mode Select co mmand, the drive can change its capacity to so mething less than maximum. See
Table 5.2.1-13 in the SCSI Interface Product Manual, part number 77738479. Refer to the Parameter list block
descriptor number of blocks field. A value of zero in the number of blocks field indicates tha t the drive shall not
change the capaci ty it is currently formatted to have. A number in the numb er of blocks field that is les s than
the maximum number of LBAs chang es the total dri ve capacity to the value in the block descriptor number of
blocks field. A value of FF FF FF FF in t he number of blocks fiel d restores th e dri ve capacity t o the maxi mum
capacity.
3.7 Factory installed accessories
OEM Standard dr ives are shipped with t he Barracuda 36 Installati on Guide, part number 7776752 9 (unless
otherwise specified ). The factory also ships wi th the drive a small bag of jumper plug s us ed for the J2, J5, an d
J6 option select jumper headers.
3.8 Options (factory instal led)
All customer request ed options are incorporate d during production or packaged at the manufacturin g 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 sector size requested.
• 4 Mbyte optional buffer size.
• Single unit shipping pack. The drive is norm ally shipped in bulk pa ckaging to provide maximum protec tion
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 Barracuda 36 Installation Guide, part number 77767529, is included with each standard OEM dr ive
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.
Barracuda 36 Product Manual, Rev. C 9
4.0 Performance characteristics
4.1 Internal drive characteristics (transparent to user)
ST136475
Drive capacity 36.4 GByte (formatted, rounded off values)
Read/write heads 20
Bytes/track 186 Kbytes (average, rounded off values)
Bytes/surface 2184 Mbytes (unformatted, rounded off values)
Tracks/surface (total) 11,721 Tracks (user accessible)
Tracks/inch 12,580 TPI
Peak bits/inch 223 KBPI
Internal data rate 137-240 Mbits/sec (variable with zone)
Disc rotational speed 7,200 r/min
Average rotational latency 4.17 msec
Recording code 16/17 EPR4
4.2 SCSI performance characteristics (visible to user)*
The values given in Section 4.2 .1 apply to all mo dels of the Barracuda 3 6 family unless otherwis e specified.
Refer to Section 9.10 and to the SC SI Interface Product Manual, part number 777384 79, for addition al timin g
details.
4.2.1 Access time [8]
Including controller overhead
(without disconnect) [1] [4]
Drive level
Read Write
msec
Average – Typical [3] 7.6 8.4
Single Track – Typical [3] 0.9 1.2
Full Stroke – Typical [3] 16 17
4.2.2 Format command execution time (minutes) [1]*
ST136475
Maximum (with verify) 80
Maximum (no verify) 40
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. [4]*
Avg. [4]
Max. [4]
16.2
25.3
28.3
MByte/sec
MByte/sec
MByte/sec
Data buffer transfer rate to/from disc media: (< 1 track):
Min. [4]
Avg. [4]
Max. [4]
MByte/sec divided by (interleave factor)
12.2
MByte/sec divided by (interleave factor)
18.8
MByte/sec divided by (interleave factor)
21.2
*[ ] All notes for Section 4.2 are listed at end of Section 4.2.3.
10 Barracuda 36 Product Manual, Rev. C
SCSI interface data transfer rate (asynchronous) [5]:
Maximum instantaneous 3.5 Mbytes/sec [6]
Maximum average 3.5 Mbytes/sec [7]
Synchronous transfer rate for SCSI Fast-20 (Ultra-1 SCSI):
16 bit data bus models 40 Mbytes/sec
Synchronous transfer rate for SCSI Fast-40 (Ultra-2 SCSI):
16 bit data bus models 80 Mbytes/sec
Synchronous transfer rate for fast SCSI-2:
16 bit data bus models 20 Mbytes/sec
Sector Sizes:
Default 512 byte user data blocks
Variable 512 to 2,048 bytes per sector in multiples of 2
bytes per sector.
If n (number of bytes per sector requested) is
odd, then n-1 sectors 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 region reallocation scheme.)
Overhead time for one track cylinder switch in sequential mod 1.1 msec (typical)
Average rotational latency 4.17 msec
Notes for Section 4.2.
[1] Execution time measur ed from receipt of the last Byte of the Co mmand Descriptor Block (CDB) to the
request for a Status Byte Tr ansfer to the Initiator (excluding connect/disconnect).
[2] Maximum times are specified over the worst case conditions of te mperature, voltage margins and drive
orientation. W hen co mpar ing spec ified a ccess times, ca re sh ould be taken to dis tingui sh bet ween typic al
access times and maximum acc ess times. The b est compar ison is o btained by syst em benchmar k tests
conducted under identical conditions. Maximum times do not include error recovery.
[3] Typical Access tim es are measu red u nder nomina l con ditio ns of temperatur e, voltage, and hor izonta l or i-
entation as measured on a representative sample of drives.
[4] Assumes no errors and no sector has been relocated.
[5] Rate measured from the start of the first sector transfer to or from the Host.
[6] Assumes system ability to support the rates listed and no cable loss.
[7] Simulated.
[8] 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 no minal voltage h as been appl ied, the d r ive becom es rea dy withi n 30 sec onds if the Mo tor
Start Opti on is disabled (i.e. the motor star ts as soon as the power has bee n applied). If a recoverable error
condition is detected during the start sequence, the drive executes a recovery procedure which may cause the
time to become rea dy to exceed 30 seconds. Dur ing spin up to ready time the dr ive responds to s ome commands over the SCSI interface in less than 1.5 seconds afte r application of power. Stop time is less than 20
seconds from removal of DC power.
Negligible
If the Motor Star t Option is en abled, the inter nal cont roller accep ts the comm ands lis ted in the SCSI Interface
Product Manual less than 3 seconds aft er DC power has been appli ed. After the Motor Start Co mmand has
been received the d rive becomes ready for nor mal opera tions withi n 13 seco nds typic ally (excluding an error
recovery procedure). The Mo tor Start Comm and can also be used to comm and the drive to stop the spindle
(see SCSI Interface Product Manual, 77738479).
There is no power control switch on the drive.
Barracuda 36 Product Manual, Rev. C 11
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 Mod e Select command with the proper values in the app licable bytes in Mode Page 08h (see SCSI Interface Product Manual
77738479). Prefetch and cache operation are inde pendent features from the st andpoint that ea ch is enabled
and disabled independently via th e Mode Select 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 pa rameter values (Mode Page 08h) for standard OEM versions of this
drive family are given in Table 9.
4.5 Cache operation
In general, all but 100 Kbytes of the physical buffer space in the drive can be used as st orage sp ace for cach e
operations. The buffer can be divided int o logi cal segm ent s (Mode Selec t Page 08h, byte 13) from which dat a
is read and to which data is wr itten. T he dr ive maintains a table of log ical block disk medium addr esses of th e
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 SCSI Interface Prod uct Manual, part numb er 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 numb er of segments ) is still use d, but only as circula r buffer
segments during d isc medium read op erations (disregard ing Prefetch operation for the moment) . That is, the
drive does not check in the buffer segments for the requested read data, but goes di rectly to the medium to
retrieve it. The retrieved data merely passes thr ou gh 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 (disc onnect/reconnect
control) in the SCSI Interface Product Manual.
The following is a simplified description of a read operation with cache operation enabled:
Case A -
1. Drive transf ers to the initiator the first LB requested plus all subsequent contiguous LB’s that are alrea dy in
2. When a requested LB is re ached th at is not i n any c ache segm ent, th e dr ive fetches it a nd any r emai ning
3. If the prefetch feature is enabled, refer to Section 4.5.2 for operation from this point.
Case B -
1. The drive fetches the requested LB’s from the disc and transfers them into a segment, an d from there to
2. If the prefetch feature is enabled, refer to Section 4.5.2 for operation from this point.
Each buffer segment is actually a s elf-contained circular storage (wrap-around oc curs), the le ngth of which is
an integer number of disc medium sectors. The wrap-around capability of the individual segments greatly
enhances the buffer’s over all 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 se gments may be sele cted using th e Mode Sel ect comma nd, but the size
can not be direct ly s elec ted. S ize is s elec ted onl y as a by-produc t of selec ting the s egment number speci fication. 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 b y the host in a Mode Sele ct comma nd
(bytes 14 and 15) no new segment size is set up by the d rive, and if the “STRICT” bit in Mode page 00h (byte
2, bit 1) is set to one, the dr ive responds as it does for any attempt to change unc hangeable parameters (see
SCSI I/O Product Manual 77738479). The dr ive supports operation of any intege r number of segm ents from 1
to 16.
A Read command is received and the first logical block (LB) is already in cache:
the cache. This data may be in multiple segments.
requested LBs from the disc an d puts them in a s egment of the cache. The dr ive transfers the remainin g
requested LBs from the ca che to t he host in accorda nce with the disconn ect/r econn ect speci fication mentioned above.
A Read command requests data, the first LB of which is not in any segment of the cache:
the host in accordance with the disconnect/reconnect specification referred to in case A.
12 Barracuda 36 Product Manual, Rev. C
4.5.1 Caching write data
Write caching is a wr ite op eration by the dr ive that makes use of a drive buffer storage area where the data t o
be written to the medium is stored in one or more segments while the drive performs the write command.
If read caching is enabled (RCD=0), then data written to the medium is retained in the cache to be made available for future read cache hits. The s ame buffer space and segme ntat ion is u sed a s set up for read func tions.
The buffer segmentation scheme is set up or changed independently, having nothing to do with the s tate of
RCD. When a write comma nd is issued, if RCD=0 , the cache is first checked to see if any logical blocks that
are to be writte n are already stored in the cach e from a previous read or write comman d. If there are, the
respective cache segments are cleared. The new data is cached for subsequent Read commands.
If the number of wri te data lo gical blocks exceeds t he size of t he segme nt being w ritte n into, when the end o f
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.
If write caching is enabled (WCE=1), then the drive may return GOOD status on a write command after the
data has been transferred into the cache, but before the data has been written to the medium. If an error occurs
while writing the data to the medium, and GOOD status has already been returned, a deferred error will be
generated. Write commands that have returned GOOD status but still have uncommitted data in the cache are
treated similarly to a normal queued command and therefore occupy a command queue slot. This may termporarily reduce the number of commands that may be queued by the host until the write data has been written to
the medium.
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. The Star t/Stop command with the stop bit s et will force a sync cache operat ion
before the drive stops.
Table 9 shows Mode default settings for the drives.
4.5.2 Prefetch operation
If the Prefetch feature is enabled, data in conti guous lo gical blocks on the disc i mmedia tely b eyond that which
was requested by a Read comman d can be retri eved and stored in the buffer for immediate transfer from the
buffer to the host on subsequent Read commands that request those logical blocks (this is true even if “cache”
operation is disabled). Though the pr efetch operation 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 Mod e Select pa ge 08h,
byte 12, bit 5 (Disable Read Ahe ad - DRA bit). DRA bit = 0 enables prefetch. Since data that is prefetched
replaces data already in some buffer segment(s), the host can lim it the amount of prefetch data to optim ize
system performance. Th e max pre fetch field (bytes 8 and 9) limits th e amount of pr efetch. The dri ve does not
use the prefetch “ceiling” field (bytes 10 and 11).
During a prefetch operation, the dri ve crosses a cyl inder bounda r y to fetch more data o nly if the Discontinuity
(DISC) bit is set to one in bit 4 of byte 2 of Mode parameters page 08h.
Whenever prefetch (read look-ahead) is enabled ( enabled by DRA = 0), it opera tes und er the co ntrol of ARLA
(Adaptive Read Look-Ahead). If the host uses software interleave, ARLA enables prefetch of contiguous blocks
from the disc when it senses that a prefetch “hit” will likely occur, even if two consecutive read operations were
not for physically contiguous blocks of data (e.g. “software interleave”). ARLA disables prefetch when it decides
that a prefetch “hit” will not likely occur. If the host is not using software i nterleave, and if two sequen tial read
operations are not for contiguous blocks of data , ARL A dis ables pre fetch, but as long as s equ enti al read oper ations request contiguous blocks of data, ARLA keeps prefetch enabled.
Barracuda 36 Product Manual, Rev. C 13
5.0 Reliability specifications
The following reliability spe cifications assume correct hos t/drive operational interface, including all interface
timings, power supply voltages, environmental requirements and drive mounting constraints (see Section 8.4).
Seek Errors
Less than 10 in 10
Read Error Rates [1]
Recovered Data Less than 10 errors in 10
Unrecovered Data Less than 1 sector in 10
Miscorrected Data Less than 1 sector in 10
MTBF 1,000,000 hours
Service Life 5 years
Preventive Maintenance None required
Note.
[1] Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.
5.1 Error rates
The error rates stated in this specification assume the following:
• The drive is operated per this specification using DC power as defined in this manual (see Section 6.2).
• The drive has been formatted with the SCSI FORMAT commands.
• Errors caused by media d efects or hos t system failures are exclude d from er ror rate comp utat ions. Refer to
Section 3.2, “Media Characteristics.”
8
seeks
12
bits transferred (OEM default settings)
15
bits transferred (OEM default settings)
21
bits transferred
5.1.1 Environmental interference
When evaluating systems operatio n under condit ions of Ele ctromagnetic Interference (EMI), the performanc e
of the drive within the s ystem shall b e consi dered acce ptable if the dr ive does not g enerate an unre coverable
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 dr ive or sys tem rec overy pro cedur es wit hou t opera tor inte rven-
tion.
5.1.2 Read errors
Before determination or measurement of read error rates:
• The data that is to be used for measurement of read error rates must be verified as being written correctly on
the media.
• All media defect induced errors must be excluded from error rate calculations.
5.1.3 Write errors
Write errors can occur as a result of media defects, environmental interference, or equipment malfunction.
Therefore, write errors are not predictable as a function of the number of bits passed.
If an unrecoverable write error occurs beca use of a n equipm ent mal functi on in the dr ive, the error is classi fied
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).
14 Barracuda 36 Product Manual, Rev. C
5.1.4 Seek errors
A seek error is de fin ed as a failure o f t he drive to position the h eads to t he add re ss ed track. Th ere shall be no
8
more than ten recoverable seek errors in 10
physical seek operations. After detecting an init ia l se ek err or, the
drive automatically p erforms an error rec overy process. If the error recovery process fails, a seek pos itioning
error (15h) is repor ted wit h a Medium err or (3h) or Har dware error (4h) repo rt ed in the Sense Key. This is an
unrecoverable seek error. Unrecoverable seek errors are classified as failures for MTBF calculatio ns. Refer to
the SCSI Inte rface Product Manual, par t number 777384 79, for Request Sense information. Se e also Appendix A of this manual for a list of sense keys and additional sense codes supported by this drive.
5.2 Reliability and service
You ca n en hance the reli abili ty of B arracuda 36 di sc dr ives by ensur ing that the dr ive receives adequa te coo ling. Section 6.0 pr ovides tempe rature me asurements and othe r information that may be used to en hance th e
service life of the drive. Section 8.3.1 provides recommended air-flow information.
5.2.1 Mean time between failure
The production d isc drive shall achieve an MTBF o f 1,000,000 hours when operated in an environment that
ensures the case temperatures specified in Section 6.4.1, Table 3, Column 2 are not exceeded. Shor t-term
excursions up to the specification limits of the operating environment will not affect MTBF performance. Continual or sustained operation at cas e 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 per i od
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 servic e. Each dis c dr ive shal l have accumulated a t leas t nine month s of o peration. Data sha ll be calc ulated
on a rolling average base for a minimum period of six months.
Drive failure means any stoppage or substandard performance caused by drive malfunction.
5.2.2 Preventive maintenance
No routine scheduled preventive maintenance shall be required.
5.2.3 Service life
The drive shall have a useful ser vic e life of five years. Depot repair or repl aceme nt of maj or parts is per m itted
during the lifetime (see Section 5.2.4).
5.2.4 Service philosophy
Special equipmen t is requir ed to repair the drive HDA. In order to achi eve the above service life, repairs must
be performed only at a proper ly equip ped and staffed ser vice and repair facility. Troubleshooting and r epair of
printed circuit board assemblies (PCBAs) in the field is not recommended, because of the extensive diagnostic
equipment required for effective servicing. Also, there are no spare parts available for this drive. Drive warranty
is voided if the HDA is opened.
5.2.5 Service tools
No special tools are requi red for site instal lat ion or recomm ended 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.
Barracuda 36 Product Manual, Rev. C 15
5.2.6 Hot plugging Barracuda 36 disc drives
The ANSI SPI-2 (T10 /1142D) documen t defines the physical requi rements for removal and inser tion of SCS I
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 Barracuda disc drives support all four hot plugging cases. Provision shall be made by the system such
that a device being inser ted ma kes power and ground connecti ons prior to the connection of any device signal
contact to the bus. A device being rem oved shall mai nta in p ower and gr oun d c onn ect ion s after th e d isco nne ction 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 processe s for the SCSI device bein g inser ted or removed shall b e quiescent. A ll SCSI devices on th e
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) mode, then all I/O processes for all devices on the bus must be completed , and the bus quiesced, before attempting to hot plug. Following the insertion of the newly installed device, the SCSI host
adapter must issue a Bus Res et, 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 (H VD) drivers and receivers and devices wit h
SE, LVD, or multimode drivers and receivers on the s ame SCSI bus since the commo n 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 co me to a complete st op prior to comple tely removing the dr ive from the cabinet
chassis. Use of the Stop Spin dle co mmand o r partial with drawal of the drive, enough to be disc onnec ted fro m
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, "S hock and vibration," of this manual.
5.2.7 S.M.A.R.T.
S.M.A.R.T. is an acronym for Self-Monitori ng Analys is and Rep or ting Technology. This technology is intended
to recognize conditions that indi cate a dri ve failure and is designed to provide suffic ient war ning of a failure to
allow data back-up before an actual failure occurs.
Note.
Each attribute ha s bee n s el ec ted to mo nit or a sp ec ifi c s et of failure conditions in the op erati ng pe rforma nc e o f
the drive, and the thresholds are optimized to minimize “false” and “failed” predictions.
Controlling S.M.A.R.T.
The operating mode of S.M.A.R.T. is controlled by the DEXCPT bit and the PERF bi t of the “Informational
Exceptions Control Mo de Page” (1Ch). The DEXCPT bit is us ed to enable or disable the S.M.A.R.T. process.
Setting the DEXCPT bit will disable all S.M.A.R.T. functions. When enabled, S.M.A.R.T. will collect on-line data
as the drive performs nor m al re ad/wr ite operatio ns. When t he PER F bit is set, th e dr ive is consi dered to be in
“On-line Mode Only” and will not perform off-line functions.
The firmware will monitor specific attributes for degradation over time but cannot predict instantaneous
drive failures.
The process of measuri ng off-line attributes and saving data can be forced by the RTZ (return to zero) command. Forcing S.M.A.R.T. will reset the timer so that the next scheduled interrupt will be two hours.
16 Barracuda 36 Product Manual, Rev. C
The drive can be interrogated by the host to determine the time remaining before the next scheduled measurement and data loggi ng process will oc cur. This is accomplished by a log sense command to log page 0x3E .
The purpose is to allow the customer to control when S.M.A.R.T. interruptions occur. As described above, forcing S.M.A.R.T by the RTZ command will reset the timer.
Performance impact
S.M.A.R.T. attribute data will be saved to the disc for the purpose of recreating the events that caused a predictive failure. The drive will measure and save parameters once every two hours subject to an idle per iod on the
SCSI bus. The process of m easuring off-line attr ibute data and saving data to th e disc is u ninterrup table 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 65 milliseconds 490 milliseconds
Reporting control
Reporting is controlled in the “Informational Exceptions Contro l Page” (1Ch). Subj ect to the reporting method ,
the firmware will issue to the “host” an 01-5D00 sense code. The error code is preser ved through bus resets
and power cycles.
Determining rate
S.M.A.R.T. monitors the rate at which errors occur and s ignals a pred ictive failure if the rate of degraded er ror
rate increases to an una cc ept able level. To determine rate, error events are logged and compared to the number of total operations for a given attr ibute. The inter val defines the number of operations over which to m easure the rate. The counter that keeps track of the c urrent number of operations is referred to as the I nterval
Counter.
S.M.A.R.T. measures error rate, hence for each attribute the occurr ence of an “error” is recorded. A counter
keeps track of the number of errors for the current interval. This counter is referred to as the Failure Counter.
Error rate is simply the number of errors per ope ration. 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 cons idered to be u nacceptable. If the numbe r of errors d oes
not exceed the threshold before the interval expires, then the error rate is considered to be acceptable. In either
case, the interval and failure counters are reset and the process starts over.
Predictive failures
S.M.A.R.T. signals predictive failures when the drive is performing unaccep tably for a period o f time. The f ir mware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accomplish this, a counte r is incremen ted whenever the error rate is una cceptable and de cremented ( not to exceed
zero) whenever the error rate is acceptable. Should the counter continually be incremented such that it reaches
the predictive threshold, a predictive failure is signaled. This counter is referred to as the Failure History
Counter. There is a separate Failure History Counter for each attribute.
5.2.8 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 mater ials on work mans hip or du e to nonc onform ance t o the app lica ble specific ations
will be repaired or replaced, at Seagate’s option and at no charge to custom er, if returned by customer at customer’s expense to Seagate’s designated facility in accordance wi th Seagate’s Warranty Procedure. Seagate
will pay for transporting th e repair or replacement item to customer. For more detailed warranty information
refer to the Standard terms and conditions of Purchase for Seagate products.
Barracuda 36 Product Manual, Rev. C 17
Shipping
When transpor ting or shipping a dr ive, a Seagate approved container must be used. Keep your origina l box.
They are easily identifi ed by the Seagate Approved Package label. Shipping a dr ive in a non-approved container voids the drive warranty.
Seagate repair centers may refuse receip t of compon ents imp roper ly pa ckaged or obviously damaged in transit. Contact your Authorized Seaga te Dis tr ibutor to pur chase addition al boxes. Seagate recommends ship ping
by an air-ride carrier experienced in handling computer equipment.
Product repair and return information
Seagate customer se rvice centers are the only facilities author ized to service Seagate drives. Seagate does
not sanction any third-par ty repair facilities. Any unauthorized repai r or tampering with the factory- seal voids
the warranty.
Barracuda 36 Product Manual, Rev. C 19
6.0 Physical/electrical specifications
This section p rovides informat ion relating to the physical and el ectrical characteristics of the Barracuda 36
drive.
6.1 AC power requirements
None.
6.2 DC power requirements
The voltage and current requirements for a single drive are shown in the following table. V alues indicated apply
at the drive power connector. The single ended power requirements i ncludes the inter nal disc dr ive SCSI I/O
terminatio n. The table shows current values in Amperes. See also Figure 3c for current and power values vs.
number of I/O operations.
Table 2: DC power requirements
ST136475
LC/LW
Notes
Voltage +5 V +12 V
Regulation [5] ±5% ±5%[2]
Average idle current DCX
[1] 0.75 0.8
Maximum starting current
(peak DC) DC
(peak AC) AC
[3]
[3]
Delayed motor start (max) DC [1][4] 0.65 0.03
Peak operating current
Typical DCX
Maximum DC
[1][6]
[1]
Maximum (Peak)
LVD
1.05 2.8
4.2
1.05
1.4
1.7
1.3
1.5
3.15
[1] Measured wi th average reading DC ammeter. Instantaneous +12 V curr ent peaks will exceed thes e val-
ues. Power supply is at nominal voltages.
[2] For +1 2 V, a –10% droop is permissible during initial start of spindle, and must return to ±5% before 7,200
rpm is reached. T he ±5% must be maintained after the drive signifies that its power-up seque nce has
been completed and that the drive is able to accept selection by the host initiator.
[3] See +12 V current profile in Figu re 3a.
[4] This co ndition occurs when the Mo tor Star t Opti on is enabled an d the dr ive has not yet received a Star t
Motor command.
[5] See Section 6.2.1 “Conducted Noise Immunity.” Specified voltage tolerance i s inclusive of ripple, noise,
and transient response.
[6] Operating condition is defined as random 8 block reads at 160.5 input/output operations per second. Cur-
rent and power specified at nom inal voltages. Increasing +5 V su pply by +5% increases 5 V cur rent by
4.62%. Decreasing +12 V supply by 5% increases +12 V current by 18.75%.
General Notes from Table 2:
1. Minimum current loading for each supply voltage is not less than 4% of the maximum operat ing current
shown.
2. The +5 and +12 volt supplies shall employ separate ground returns.
3. Where power is provided to multiple drives from a common supply, careful consideration for individual drive
power requirements should be noted. Where multiple units are powered on simultaneously, the peak starting current must be available to each device.
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