Seagate ST973401SS, ST936701SS User Manual

Product Manual

Savvio SAS

ST973401SS ST936701SS

100350598 Rev. D August 2007

Copyright © 2007 Seagate Technology LLC. All rights reserved. Printed in U.S.A. Publication number: 100350598, Rev. D, August 2007 Seagate, Seagate Technology and the Wave logo are registered trademarks of Seagate Technology LLC

in the United States and/or other countries. Savvio, SeaTools and SeaTDD are either trademarks or registered trademarks of Seagate Technology LLC or one of its affiliated companies in the United States and/or other countries. All other trademarks or registered trademarks are the property of their respective owners.

One gigabyte, or GB, equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment and formatting. Quantitative usage examples for various applications are for illustrative purposes. Actual quantities will vary based on various factors, including file size, file format, features and application software. Seagate reserves the right to change, without notice, product offerings or specifications.

Savvio SAS Product Manual, Rev. D

Contents

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

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

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

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

2.1.2 Electromagnetic compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.2 Reference documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.0 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.1 Standard features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.2 Media description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.3 Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.4 Reliability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.5 Formatted capacities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.6 Programmable drive capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.7 Factory-installed accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.8 Factory-installed options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.9 User-installed accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4.0 Performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.1 Internal drive characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.2 Seek performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.2.1 Access time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.2.2 Format command execution time for 512-byte sectors (minutes) . . . . . . . . . . . 12

4.2.3 General performance characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.3 Start/stop time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.4 Prefetch/multi-segmented cache control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.5 Cache operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4.5.1 Caching write data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.5.2 Prefetch operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.5.3 Optimizing cache performance for desktop and server applications . . . . . . . . . 15

5.0 Reliability specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.1 Error rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.1.1 Recoverable Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.1.2 Unrecoverable Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.1.3 Seek errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.1.4 Interface errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2 Reliability and service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2.1 Mean time between failure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2.2 Preventive maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.2.3 Hot plugging the drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.2.4 S.M.A.R.T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5.2.5 Thermal monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

5.2.6 Drive Self Test (DST). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

5.2.7 Product warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

6.0 Physical/electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.1 AC power requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.2 DC power requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.2.1 Conducted noise immunity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.2.2 Power sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.2.3 Current profiles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.3 Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

6.4 Environmental limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Savvio SAS Product Manual, Rev. D

6.4.1 Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.4.2 Relative humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.4.3 Effective altitude (sea level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

6.4.4 Shock and vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

6.4.5 Air cleanliness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

6.4.6 Corrosive environment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

6.4.7 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.4.8 Electromagnetic susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.5 Mechanical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

7.0 Defect and error management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.1 Drive internal defects/errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.2 Drive error recovery procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

7.3 SAS system errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

8.0 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

8.1 Drive orientation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

8.2 Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

8.3 Drive mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

8.4 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

9.0 Interface requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

9.1 SAS features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

9.1.1 task management functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

9.1.2 task management responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

9.2 Dual port support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

9.3 SCSI commands supported. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

9.3.1 Inquiry data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

9.3.2 Mode Sense data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

9.4 Miscellaneous operating features and conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

9.4.1 SAS physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

9.4.2 Physical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

9.4.3 Connector requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

9.4.4 Electrical description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

9.4.5 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

9.4.6 SAS transmitters and receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

9.4.7 Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

9.5 Signal characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

9.5.1 Ready LED Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

9.5.2 Differential signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

10.0 Seagate Technology support services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Savvio SAS Product Manual, Rev. D

iii

List of Figures

Figure 1. Typical ST973401SS drive +12V current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 2. Typical ST973401SS drive +5V current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 3. Typical ST936701SS drive +12V current profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 4. Typical ST936701SS drive +5V current profile. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 5. ST973401SS (3 Gbit) DC current and power vs. input/output operations per second. . . . . . 30

Figure 6. ST973401SS (1.5 Gbit) DC current and power vs. input/output operations per second . . . . 30

Figure 7. ST936701SS (3 Gbit) DC current and power vs. input/output operations per second. . . . . . 31

Figure 8. ST936701SS (1.5 Gbit) DC current and power vs. input/output operations per second . . . . 31

Figure 9. Location of the HDA temperature check point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 10. Recommended mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 11. Mounting configuration dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Figure 12. Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Figure 13. Air flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Figure 14. Physical interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Figure 15. SAS device plug dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Figure 16. SAS device plug dimensions (detail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Figure 17. SAS transmitters and receivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Figure 18. Receive eye mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Figure 19. Reveive tolerance eye mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Figure 20. Sinusoidal jitter mask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Figure 21. Compliance interconnect test load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Figure 22. Zero-length test load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Figure 23. ISI loss example at 3.0 Gbps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Figure 24. ISI loss example at 1.5 Gbps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Savvio SAS Product Manual, Rev. D

1.0 Scope

This manual describes Seagate Technology® LLC, Savvio® SAS (Serial Attached SCSI) disc drives. Savvio drives support the SAS Protocol specifications to the extent described in this manual. The SAS Inter-

face Manual (part number 100293071) describes the general SAS characteristics of this and other Seagate SAS drives.

Figure 1. Savvio family disc drive

Savvio SAS Product Manual, Rev. D

2.0 Applicable standards and reference documentation

The drive has been d evelope d as a system p eriphe ral to the hig hest st and ards of desig n and constru c tion. The drive depends on its host equipment to provide adequate power and environment for optimum performance and compliance with applicable industry and governmental regulations. Special attention must be given in the areas of safety, power distribution, shielding, audible noise control, and temperature regulation. In particular, the drive must be securely mounted to guarantee the specified performance characteristics. Mounting by bottom holes must meet the requirements of Section 8.3.

2.1 Standards

The Savvio family complies with Seagate standards as noted in the appropr iate sections of this manual and the Seagate SAS Interface Manual, part number 100293071.

The Savvio disc drive is a UL recognized component per UL1950, CSA certified to CAN/CSA C22.2 No. 95095, and VDE or TUV certified to EN60950.

2.1.1 Electromagnetic compatibility

The drive, as delivered, is designed for system integration and installation into a suitable enclosure prior to use. The drive is supplied as a subassembly and is not subject to Subpart B of Part 15 of the FCC Rules and Regulations nor the Radio Interference Regulations of the Canadian Department of Communications.

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

2.1.1.1 Electromagn etic susc ept ibili ty

As a component assembly, the drive is not required to meet any susceptibility performance requirements. It is the responsibility of those integrating the drive within their systems to perform those tests required and design their system to ensure that equipment operating in the same system as the drive or external to the system does not adversely affect the performance of the drive. See Tables 12 and 13, DC power requirements.

Savvio SAS Product Manual, Rev. D

2.1.2 Electromagn etic complia nce

Seagate uses an independent laboratory to confirm compliance with the directives/standards for CE Marking and C-Tick Marking. T he dr ive was tested in a r epres ent ative system for typical applications. The select ed sys tem represents the most popular characteristics for test platforms. The system configurations include:

• Typical current use microprocessor

• 3.5-inch floppy disc drive

• Keyboard

• Monitor/display

•Printer

• External modem

•Mouse Although the test system with th is Seag ate mo del comp lies with the dir ectives/st and ards, we cannot gu aran tee

that all systems will comply. The computer manufacturer or system integrator shall confirm EMC compliance and provide the appropriate marking for their product.

Electromagnetic compliance for the European Union

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

Australian C-Tick

If this model has the C-Tick Marking it complies with the Australia/New Zealand Standard AS/NZS3548 1995 and meets the Electromagnetic Compatibility (EMC) Framework requirements of Australia’s Spectrum Management Agency (SMA).

Korean MIC

If this model has the Korean Min ist ry of Infor mat ion and Com munication (MIC) logo, it complie s with par agr aph 1 of Article 11 of the Electromagnetic Compatibility (EMC) Control Regulation and meets the Electromagnetic Compatibility Framework requirements of the Radio Research Laboratory (RRL) Ministry of Information and Communication Republic of Korea.

Taiwanese BSMI

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

Savvio SAS Product Manual, Rev. D

2.2 Reference documents

Savvio SAS Installation Guide

Seagate part number: 100350599

SAS Interface Manual

ANSI SAS Documents

ANSI Small Computer System Interface (SCSI) Documents

Specification for Acoustic Test Requirement and Procedures

Package Test Specification Seagate P/N 30190-001 (under 100 lb.) Package Test Specification Seagate P/N 30191-001 (over 100 lb.)

In case of conflict between this document and any referenced document, this document takes precedence.

Seagate part number: 100293071

SFF-82232.5” Drive Form Factor with Serial Connector SFF-8460HSS Backplane Design Guidelines SFF-8470Multi Lane Copper Connector SFF-8482SAS Plug Connector ANSI INCITS.xxx Serial Attached SCSI (SAS) Standard (T10/1562-D) ISO/IEC 14776-xxxSCSI Architecure Model-3 (SAM-3) Standard (T10/1561-D) ISO/IEC 14776-xxxSCSI Primary Commands-3 (SPC-3) Standard (T10/1416-D) ISO/IEC 14776-xxxSCSI Block Commands-2 (SBC-2) Standard (T10/1417-D)

X3.270-1996(SCSI-3) Architecture Model

Seagate part number: 30553-001

Savvio SAS Product Manual, Rev. D

3.0 General description

Savvio drives combine Tunneling Magnetoresistive (TMR) heads and a Serial Attached SCSI (SAS) interface to provide high pe rfor mance , high cap acity d at a sto rage for a va riety o f system s includ ing en gineering wor kst a tions, network servers, mainframes, and supercomputers. The Serial Attached SCSI interface is designed to meet next-generation computing demands for performance, scalability, flexibility and high-density storage requirements.

Savvio drives are random access storage devices designed to support the Serial Attached SCSI Protocol as described in the ANSI specifications, this document, and the SAS Interface Manual (part number 100293071) which describes the general interface characteristics of this drive. Savvio drives are classified as intelligent peripherals and provide level 2 conformance (highest level) with the ANSI SCSI-1 standard. The SAS connectors, cables and electrical interface are compatible with Serial ATA (SATA), giving future users the choice of populating their syste ms with eithe r S AS or SATA har d d isc dr ives. This allo ws you to continue to levera ge yo ur existing investment in SCSI while gaining a 3Gb/s serial data transfer rate.

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

Note. Never disassemble the HDA and do not attempt to service items in the sealed enclosure (heads,

media, actuator, etc.) as this requires special facilities. The drive does not contain user-replaceable parts. Opening the HDA for any reason voids your warranty.

Savvio drives use a dedicated landing zone at the innermost radius of the media to eliminate the possibility of destroying or de grad i ng d at a b y l and ing in the data zone. Th e h eads autom atical ly go t o the landing zone when power is removed from the drive.

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

Savvio drives decode track 0 location data from the servo data embedded on each surface to eliminate mechanical transducer adjustments and related reliability concerns.

The drives also use a high-performance actuator assembly with a low-inertia, balanced, patented, straight arm design that provides excellent performance with minimal power dissipation.

Savvio SAS Product Manual, Rev. D

3.1 Standard featu re s

Savvio drives have the following standard features:

• 1.5 / 3 Gbit Serial Attached SCSI (SAS) interface

• Integrated dual port SAS controller supporting the SCSI protocol

• Support for SAS expanders and fanout adapters

• Firmware downloadable using the SAS interface

• 64 - deep task set (queue)

• Supports up to 32 initiators

• Jumperless configuration.

• User-selectable logical block size (512 to 528 bytes per logical block) in any multiple of 4 bytes.

• Industry standard SFF 2.5-inch dimensions

• Programmable logical block reallocation scheme

• Flawed logical block reallocation at format time

• Programmable auto write and read reallocation

• Reallocation of defects on command (Post Format)

• ECC maximum burst correction length of 320 bits

• No preventive maintenance or adjustments required

• Dedicated head landing zone

• Embedded servo design

• Automatic shipping lock

• Self diagnostics performed when power is applied to the drive

• Zone bit recording (ZBR)

• Vertical, horizontal, or top down mounting

• Dynamic spindle brake

• 8,192 Kbyte data buffer (see Secti on 4.5).

• Drive Self Test (DST)

• Background Media Scan (BGMS)

• Power Save

3.2 Media desc ription

The media used on the drive has an aluminum substrate coated with a thin film magnetic material, overcoated with a proprietary protective layer for improved durability and environmental protection.

3.3 Performance

• Programmable multi-segmentable cache buffer

• 300 Mbytes/sec maximum instantaneous data transfers.

• 10k RPM spindle. Average latency = 3.0 msec

• Background processing of queue

• Supports start and stop commands (spindle stops spinning)

• Adaptive seek velocity; improved seek performance

Savvio SAS Product Manual, Rev. D

3.4 Reliability

• Mean time between failures (MTBF) of 1,400,000 hours

• LSI circuitry

• Balanced low mass rotary voice coil actuator

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

• 5-year warranty

3.5 Formatted ca pacities

Standard OEM models are formatted to 512 bytes per block. The block size is selectable at format time and must be a multiple of 4 bytes. Users having the necessary equipment may modify the data block size before issuing a format command and obtain different formatted capacities than those listed.

To provide a stable target capacity environment and at the same time provide users with flexibility if they choose, Seagate recommends product planning in one of two modes:

1. Seagate designs specify capacity points at certain block sizes that Seagate guarantees current and future products will meet. We recommend customers use this capacity in their project planning, as it ensures a stable operating point with backward and forward compatibility from generation to generation. The current guaranteed operating points for this product are:

Capacity (Blocks)

ST936701SS ST973401SS

Sector Size

Decimal Hex Decimal Hex

512 71,687,372 445DCCC 143,374,744 88BB998 520 70,197,546 42F212A 140,395,092 85E4254 524 68,766,592 4194B80 137,577,184 83342E0

2. Seagate drives also may be used at the maximum available capacity at a given block size, but the excess capacity above the guaranteed level will vary between other drive families and from generation to generation, depending on how each block size actually formats out for zone frequencies and splits over servo bursts. This added capacity potential may range from 0.1 to 1.3 percent above the guaranteed capacities listed above. Using the drives in this manner gives the absolute maximum capacity potential, but the user must determine if the extra capacity potential is useful, or whether their assurance of backward and forward compatibility takes precedence.

3.6 Programmable drive capacity

Using the Mode Select command, the drive can change its capacity to something less than maximum. See the Mode Select (6) parameter list table in the SAS Interface Manual, part number 100293071. A value of zero in the Number of Blocks field indicates that the drive will not change the capacity it is currently formatted to have. A number other than zero and less than the maximum number of LBAs in the Number of Blocks field changes the total drive cap acity to the value in the Nu mber of Blocks field. A value gre ater t han th e maxim um nu mbe r of LBAs is rounded down to the maximum capacity.

3.7 Factory -installed acce ssories

OEM standard drives are shipped with the Savvio SAS Installation Guide (part number 100350599).

Savvio SAS Product Manual, Rev. D

3.8 Factory-installed options

Yo u may order the following items which are incorporated at the manufacturing facility d uring production or packaged before shipping. Some of the options available are (not an exhaustive list of possible options):

• Other capacities can be ordered depending on sparing scheme and sector size requested.

• Single-unit shipping pack. The drive is normally shipped in bulk packaging to provide maximum protection against transit damage. U nit s shipped individually require add itional pro tection as pr ovided by th e singl e unit shipping pack. Users planning single unit distribution should specify this option.

• The Savvio SAS Installation Guide, part number 100350599, is usually included with each standard OEM drive shipped, but extra copies may be ordered.

• The Safety and Regulatory Agency Specifications, part number 75789512, is usually included with each standard OEM drive shipped, but extra copies may be ordered.

3.9 User-ins talle d accessorie s

The following accessories are available. All kits may be installed in the field.

• Single-unit shipping pack.

Savvio SAS Product Manual, Rev. D

4.0 Performance characteristics

This section provides de ta iled inform ation concerning perform ance-rel ate d chara cteristi cs an d featur es of Sav vio drives.

4.1 Internal drive characteristics

ST973401SS ST936701SS

Drive capacity 73.4 36.7 Gbytes (formatted, rounded off value) Read/write data heads 4 2 Bytes per track 360,000 360,000 Bytes (average, rounded off values) Bytes per surface 18,387 18,387 Mbytes (unformatted, rounded off value) Tracks per surface (total) 51,052 51,052 Tracks (user accessible) Tracks per inch 105 105 KTPI Peak bits per inch 660 660 KBPI Internal data rate 506-753 506-753 Mbits/sec (variable with zone) Disc rotation speed 10k 10k rpm Avg rotational latency 3.0 3.0 msec

4.2 Seek performance characteristics

See Section 9.4.1, "SAS physical interface" on page 56 and the SAS Interface Manual (part number

100293071) for additional timing details.

4.2.1 Access time

Including controller overhead (msec)

Read Write Read Write

Average Typical Single track Typical Full stro ke Typical

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

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

3. Typical access times are measured under nominal conditions of temperature, voltage, and horizontal orientation as measured on a representative sample of drives.

4. Access time = controller overhead + average seek time and applies to all data transfer commands. Access to data = access time + latency time.

3,4

4.2 4.6 4.0 4.4

0.40 0.80 0.20 0.60

8.3 8.8 8.1 8.6

1, 2

Not including controller overhead (msec)

1,2

Savvio SAS Product Manual, Rev. D

4.2.2 Format command execution time for 512-byte sectors (minutes)

ST973401SS ST936701SS

Maximum (wi th verify) Maximum (without verify)

52 26 26 13

4.2.3 General performance characteristics

Minimum sector interleave 1 to 1

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

Minimum 63 MBytes/sec Maximum 94 MBytes/sec

SAS Interface maximum instantaneous transfer rate 300 Mbytes/sec* per

Logical block sizes

Default is 512-byte data blocks Variable 512 to 528 bytes per sector in evenly divisible by 4 number of bytes per sector (512, 516, 520, 524, or 528). If n (number of bytes per sector is not divisible by 4, the next lowest number that is devisi ble by 4 will be used.

Read/write consecutive sectors on a track Yes

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

Average rotational latency 3.0 msec

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

port (dual port = 600 Mbytes/sec*)

Negligible

Savvio SAS Product Manual, Rev. D

4.3 Start/stop time

The drive accepts the commands listed in the SAS Interface Manual less than 3 seconds after DC power has been applied.

If the drive receives a NOTIFY (ENABLE SPINUP) primitive through either port and has not received a START STOP UNIT command with the START bit equal to 0, the drive becomes ready for normal operations within 20 seconds (excluding the error recovery procedure).

If the drive receives a START STOP UNIT command with the START bit equal to 0 before receiving a NOTIFY (ENABLE SPINUP ) pri mitive, the drive waits for a S TART STOP UNIT com mand wi th th e START bit equal to 1. After receiving a START STOP UNIT command with the START bit equal to 1, the drive waits for a NOTIFY (ENABLE SPINUP) primitive. After receiving a NOTIFY (ENABLE S PINUP) primitive through either port, the drive becomes ready for normal operations within 20 seconds (excluding the error recovery procedure).

If the drive receives a START STOP UNIT command with the START bit and IMMED bit equal to 1 and does not receive a NOTIFY (ENABLE SPINUP) primitive within 5 seconds, the drive fails the START STOP UNIT command.

The START S TOP UN IT comm and m ay be used to comm and the dr ive to stop the spindle. Stop time is 30 seconds (maximum) from removal of DC power. There is no power control switch on the drive.

4.4 Prefetch /m ulti-segmen te d cache contro l

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

All default cache and prefetch mode parameter values (Mode Page 08h) for standard OEM versions of this drive family are given in Table 19.

4.5 Cache operation

Note. Refer to the SAS Interface Manual for more detail concerning the cache bits.

Of the 8,192 kbytes physical buffer space in the drive, approximately 6,900 kbytes can be used as a cache. The buffer can be divi ded into log i cal segm ent s (u sing M ode S elect Pa ge 08 h, byte 13) from which data is read and to which data is written.

The drive keeps track of the logical block addresses of the data stored in each segment of the buffer. If the cache is enabled (see RCD bit in the SAS Interface Manual ), data req uested by the host w ith a rea d comm and is retrieved from the buf fe r, if possible, before any disc access is initiated . If cach e oper ation is not en abled, the buffer (still segmented with the required number of segments) is still used, but only as circular buffer segments during disc medium read operations (disregarding Prefetch operation for the moment). That is, the drive does not check in the buffe r segm ents for the requested re ad dat a, but goes directly to the m edium to ret rieve i t. The retrieved data merely passes through some buffer segment on the way to the host. On a cache miss, all data transfers to the host are in accordance with buffer-full ratio rules. On a cache hit, the drive ignores the bufferfull ratio rules. See the explanation provided with the information about Mode Page 02h (disconnect/reconnect control) in the SAS Interface Manual.

The following is a simplified description of the prefetch/cache operation: Case A—read command is received and the first logical block is already in the cache:

1. Drive transfers to the initiator the first logical block requested plu s all subsequent cont ig uous logical bl ocks

that are already in the cache. This data may be in multiple segments.

Savvio SAS Product Manual, Rev. D

2. When a requested logical block is reached that is not in any cache segment, the drive fetches it and any remaining requested logical block addresses from the disc and puts them in a segment of the cache. The drive transfers the remaining requested logical blocks from the cache to the host in accordance with the Mode Select Disconnect/Reconnect parameters, page 02h.

3. If the prefetch feature is enabled, refer to section 4.5.2 for operation from this point.

Case B—A Read command requests data, and the first logical block is not in any segment of the cache:

1. The drive fetches the requested logical blocks from the disc and transfers them into a segment, and then from there to the host in accordance with the Mode Select Disconnect/Reconnect parameters, page 02h.

2. If the prefetch feature is enabled, refer to section 4.5.2 for operation from this point.

During a prefetch, the drive crosses a cylinder boundary to fetch data only if the Discontinuity (DISC) bit is set to 1 in bit 4 of byte 2 of the Mode Select parameters page 08h. Default is zero for bit 4.

Each cache segment is actually a self-contained circular buffer whose length is an integer number of logical blocks. The wrap-around capability of the individual segments greatly enhances the cache’s overall performance, allowing a wide range of user-selectable configurations. The drive supports operation of any integer number of segments from 1 to 16. Divide the 6,900 Kbytes in the buffer by the number of segments to get the segment size. Default is 3 segments.

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

The value 0XFFFF is always reported regardless of the actual size of the segment. Sending a size specification using the Mode Select command (bytes 14 and 15) does not set up a new segment size. If the STRICT bit in Mode page 00h (byte 2, bit 1) is set to one, the drive responds as it does for any attempt to change an unchangeable parameter.

4.5.1 Caching write data

Write caching is a write operation by the drive that makes use of a drive buffer storage area where the data to be written to the medium is stored while the drive performs the Write command.

If read caching is enabled (RCD=0), then data written to the medium is retained in the cache to be made available for future read cache hits. The same buffer space and segmentation is used as set up for read functions. The buffer segmentation scheme is set up or changed independently, having nothing to do with the state of RCD. When a write command is issued, if RCD=0, the cache is first checked to see if any logical blocks that are to be written are already stored in the cache from a previous read or write command. If there are, the respective cache segments are cleared. The new data is cached for subsequent Read commands.

If the number of write dat a logical blo cks excee d the size o f the segm ent b eing wr itten into, wh en th e en d of the segment is reached, the data is written i nto the b eginning of the same cache segment, overwriting the dat a that was written there at the beginning of the operation; however, the drive does not overwrite data that has not yet been written to the medium.

If write caching is enabled (WCE=1), then the drive may return Good status on a write command after the data has been transferred into the cache, but before the data has been written to the medium. If an error occurs while writing the data to the medium, and Good status has already been returned, a deferred error will be generated.

The Synchronize Ca che command may be used to force the drive to write all cached wri te dat a to the med ium. Upon completion of a Synchronize Cache command, all data received from previous write commands will have been written to the medium.

Table 19 shows the mode default settings for the drive.

Savvio SAS Product Manual, Rev. D

4.5.2 Prefetch operation

If the Prefetch feature is enabled, data in contiguous logical blocks on the disc immediately beyond that which was requested by a Read command are retrieved and stored in the buffer for immediate transfer from the buffer to the host on subsequent Read commands that request those logical blocks (this is true even if cache operation is disabled). Though the prefetch operation uses the buffer as a cache, finding the requested data in the buffer is a prefetch hit, not a cache operation hit.

To enable Prefetch, use Mode Select page 08h, byte 12, bit 5 (Disable Read Ahead - DRA bit). DRA bit = 0 enables prefetch.

Since data that is prefetched replaces data already in some buffer segments, the host can limit the amount of prefetch data to optimize system performance. The Max Prefetch field (bytes 8 and 9) limits the amount of prefetch. The drive does not use the Prefetch Ceiling field (bytes 10 and 11).

During a prefetch operation, the drive crosses a cylinder boundary to fetch more data only if Mode parameters page 08h, byte 2, bit 4 is set to 1 (Discontinuity--DISC bit).

When prefetch (read look-ahead) is enabled (enabled by DRA = 0), it operates under the control of ARLA (Adaptive Read Look-Ahead). If the host uses software interleave, ARLA enables prefetch of contiguous blocks from the disc when it senses that a prefetch hit will likely occur, even if two consecutive read operations were not for physically contiguous blocks of data (e.g. “software interleave”). ARLA disables prefetch when it decides that a prefetch hit will not likely occur. If the host is not using software interleave, and if two sequential read operations are not for contiguous blocks of data, ARLA disables prefetch, but as long as sequential read operations request contiguous blocks of data, ARLA keeps prefetch enabled.

4.5.3 Optimizing cache performance for desktop and server applications

Desktop and server applications require different drive caching operations for optimal performance. This means it is difficult to provide a single configuration that meets both of these needs. In a desktop environment, you want to configure the cache to respond quickly to repetitive accesses of multiple small segments of data without taking the time to “look ahead” to the next contiguous segments of data. In a server environment, you want to configure the cache to provide large volumes of sequential data in a non-repetitive manner. In this case, the ability of the cache to “look ahead” to the next contiguous segments of sequential data is a good thing.

The Performance Mode (PM) bit controls the way the drive switches the cache buffer into different modes of segmentation. In “server mode” (PM bit = 0), the drive can dynamically change the number of cache buffer segments as needed to optimize the performance, based on the command stream from the host. In “desktop mode” (PM bit = 1), the number of segments is maintained at the value defined in Mode Page 8, Byte 13, at all times (unless changed by using a Mod e Select comman d). Fo r addi tion al information about the PM bit, refer to the Unit Attention Parameters page (00h) of the Mode Sense command (1Ah) in the SAS Interface Manual, part number 100293071.

Savvio SAS Product Manual, Rev. D

5.0 Reliability specifications

The following reliability specifications assume correct host and drive operational interface, including all interface timings, power supply voltages, environmental requirements and drive mounting constraints.

Seek error rate: Less than 10 errors in 108 seeks Read Error Rates

Recovered Data Less than 10 errors in 1012 bits transferred (OEM default settings) Unrecovered Data Less than 1 sector in 1015 bits transferred

Miscorrected Data Less than 1 sector in 1021 bits transferred Interface error rate: Less than 1 error in 1012 bits transferred MTBF: 1,400,000 hours Service Life 5 years Preventive maintenance: None required

1. Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.

5.1 Error rate s

The error rates stated in this manual assume the following:

• The drive is operated in accordance with this manual using DC power as defined in paragraph 6.2, "DC power requirements."

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

• Assume random data.

• Default OEM error recovery settings are applied. This includes AWRE, ARRE, full read retries, full write retries and full retry time.

5.1.1 Recoverable Errors

Recovereable errors are those detected and corrected by the drive, and do not require user intervention. Recoverable Data errors will use correction, although ECC o n-the-fly is not considered fo r purposes o f recov-

ered error specifications. Recovered Data error rate is determined using read bits transferred for recoverable errors occurring during a

read, and using write bits transferred for recoverable errors occurring during a write.

5.1.2 Unrecoverable Errors

An unrecoverable data error is defined as a failure of the drive to recover data from the media. These errors occur due to head/media or write problems. Unrecoverable data errors are only detected during read operations, but not caused by the read. If an unrecoverable data error is detected, a MEDIUM ERROR (03h) in the Sense Key will be reported. Multiple unrecoverable data errors resulting from the same cause are treated as 1 error.

Savvio SAS Product Manual, Rev. D

5.1.3 Seek errors

A seek error is defined as a failure of the drive to position the heads to the addressed track. After detecting an initial seek error, the drive automaticall y perf orms an error recovery process. If the error recover y process fails, a seek positioning error (Error code = 15h or 02h) will be reported with a Hardware error (04h) in the Sense Key. Recoverable seek errors are specified at Less than 10 errors in 108 seeks. Unrecoverable seek errors (Sense Key = 04h) are classified as drive failures.

5.1.4 Interface errors

An interface error is defined as a failure of the receiver on a port to recover the data as transmitted by the device port connected to the receiver. The error may be detected as a running disparity error, illegal code, loss of word sync, or CRC error.

5.2 Reliability and service

You can enhance the reliability of Savvio disc drives by ensuring that the drive receive s adequ ate coo ling. S ection 6.0 provides temperature measurements and other information that may be used to enhance the service life of the drive. Section 8.2 provides recommended ai r-f low information.

5.2.1 Mean time between failure

The production disc drive shall achieve an MTBF of 1,400,000 hours when operated in an environment that ensures the HDA case temperatures specified in Section 6.4 are not exceeded. Short-term excursions up to the specification limits of the operating environment will not affect MTBF performance. Continual or sustained operation at case temperatures above the values shown in Section 6.4.1 may degrade product reliability.

The MTBF target is specified as device power-on hours (POH) for all drives in service per failure. Estimated power-on operating hours in the period = MTBF per measurement period

Number of drive failures in the period

Estimated power-on operation hours means power-up hours per disc drive times the total number of disc drives in service. Each disc drive shall have accumulated at least nine months of operation. Data shall be calculated on a rolling average base for a minimum period of six months.

MTBF is based on the following assumptions:

• 8,760 power-on hours per year.

• 250 average on/off cycles per year.

• Operations at nominal vo ltages.

• Systems will provide adequate cooling to ensure the case temperatures specified in Section 6.4.1 are not exceeded.

Drive failure means any stoppage or substandard performance caused by drive malfunction. A S.M.A.R.T. predictive failure indicates that the drive is deteriorating to an imminent failure and is considered

an MTBF hit.

5.2.2 Preventive mainte nan ce

No routine scheduled preventive maintenance is required.

Savvio SAS Product Manual, Rev. D

5.2.3 Hot plugging the drive

When a disc is powered on by switching the power or hot plugged, the drive runs a self test before attempting to communicate on its’ interfaces. When the self test completes successfully, the drive initiates a Link Reset starting with OOB. An attached device should respond to the link reset. If the link reset attempt fails, or any time the drive looses sync, the drive initiated link reset. The drive will initiate link reset once per second but alternates between port A and B. Therefore each port will attempt a link reset once per 2 seconds assuming both ports are out of sync..

If the self-test fails, the drive does not respond to link reset on the failing port. Note. It is the responsibility of the systems integrator to assure that no temperature, energy, voltage haz-

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

Caution. The drive motor must come to a com pl ete s top pr ior to ch angi ng the pla ne of o pera ti on. T his time i s

required to insure data integrity.

5.2.4 S.M.A.R.T.

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

Note. The drive’ s f irmwar e moni tor s specific attr ibutes for degr adatio n ove r tim e b ut can ’ t predi ct in sta nt a-

neous drive failures.

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

Controlling S.M.A.R.T.

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

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

You can interrogate the drive through th e host t o dete rmine the time remaining b efore the ne xt schedu l ed me asurement and d at a logg i ng p rocess occur s . To accomplish this, i ssue a Log Sense command to log page 0x3E. This allows you to control when S.M.A.R.T. interruptions occur. Forcing S.M.A.R.T. with the RTZ command resets the timer.

Performance impact

S.M.A.R.T. attribute data is saved to the disc so that the events that caused a predictive failure can be recreated. The drive measures and saves parameters once every two hours subject to an idle period on the drive interfaces. The process of measuring off-line attribute data and saving data to the disc is uninterruptable. The maximum on-line only processing delay is summarized below:

Maximum processing delay

S.M.A.R.T. delay times

On-line only delay DEXCPT = 0, PERF = 1

50 milliseconds

Fully-enabled delay DEXCP T = 0, PE R F = 0

300 milliseconds

Savvio SAS Product Manual, Rev. D

Reporting control

Reporting is controlled by the MRIE bits in the Informational Exceptions Control mode page (1Ch). Subject to the reporting method, the firmware will issue to the host an 01-5Dxx sense code. The error code is preserved through bus resets and power cycles.

Determining rate

S.M.A.R.T. monitors the rate at which errors occur and si gna ls a predi ctive fai lure if the rat e of degrad ed err ors increases to an unacceptabl e level. To determine rate, error events are logged and com pa red to the num ber of total operations for a given attribute. The interval defines the number of operations over which to measure the rate. The counter that keeps track of the current number of operations is referred to as the Interval Counter.

S.M.A.R.T. measures error rates. All errors for each monitored attribute are 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 the number of errors per oper ation. The algori thm tha t S .M.A.R .T. uses to record rate s of err or i s to set thresholds for the number of errors and their interval. If the number of errors exceeds the threshold before the interval expires, the error rate is considered to be unacceptable. If the number of errors does not exceed the threshold before the interval expires, the error rate is considered to be acceptable. In either case, the interval and failure counters are reset and the process starts over.

Predictive failures

S.M.A.R.T. signals predictive failures when the drive is performing unacceptably for a period of time. The firmware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accomplish this, a counter is incremented each time the error rate is unacceptable and decremented (not to exceed zero) whenever the error rate is acceptable. If the counter continually increments 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.

5.2.5 Thermal monitor

Savvio drives implement a temperature warning system which:

1. Signals the host if the temperature exceeds a value which would threaten the drive.

2. Signals the host if the temperature exceeds a user-specified value.

3. Saves a S.M.A.R.T. data frame on the drive which exceeds the threatening temperature value.

A temperature sensor monitors the drive temperature and issues a warning over the interface when the temperature exceeds a set threshold. The temperature is measured at power-up and then at ten-minute intervals after power-up.

The thermal monitor system generates a warning code of 01-0B01 when the temperature exceeds the specified limit in compliance with the SCSI standard. The drive temperature is reported in the FRU code field of mode sense dat a. You can use this infor matio n to deter mine if the warning i s due to t he tem per atur e excee ding the drive threatening temperature or the user-specified temperature.

This feature is controlled by the En able W a rni ng (EWasc) bit, and the reporting mechanism is controlled by the Method of Reporting Informational Exceptions field (MRIE) on the Informational Exceptions Control (IEC) mode page (1Ch).

The current algorithm implements two temperature trip points. The first trip point is set at 65°C which is the maximum temperature limit according to the drive specification. The second trip point is user-selectable using the Log Select command. The reference temperature parameter in the temperature log page (see Table 11)

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