Seagate ST300MM0026 Savvio 10K.1 SAS Product Manual - Page 26

20

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 signals a predictive failure if the rate of degraded errors

increases to an unacceptable level. To determine rate, error events are logged and compared to the number of

total operations for a given attribute. The interval defines the number of operations over which to measure the

rate. The counter that keeps track of the current number of operations is referred to as the Interval Counter.

S.M.A.R.T. measures error 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 operation. The algorithm that S.M.A.R.T. uses to record rates of error is to

set thresholds for the number of errors and 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 inter-

val 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 firm-

ware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accom-

plish 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 pre-

dictive 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 tem-

perature 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 speci-

fied limit in compliance with the SCSI standard. The drive temperature is reported in the FRU code field of

mode sense data. You can use this information to determine if the warning is due to the temperature exceeding

the drive threatening temperature or the user-specified temperature.

This feature is controlled by the Enable Warning (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)

Section	Page
1.0 Scope	7
2.0 Applicable standards and reference documentation	9
2.1 Standards	9
2.1.1 Electromagnetic compatibility	9
2.1.1.1 Electromagnetic susceptibility	9
2.1.2 Electromagnetic compliance	10
2.2 Reference documents	11
3.0 General description	13
3.1 Standard features	14
3.2 Media description	14
3.3 Performance	14
3.4 Reliability	15
3.5 Formatted capacities	15
3.6 Programmable drive capacity	15
3.7 Factory-installed accessories	15
3.8 Factory-installed options	16
3.9 User-installed accessories	16
4.0 Performance characteristics	17
4.1 Internal drive characteristics	17
4.2 Seek performance characteristics	17
4.2.1 Access time	17
4.2.2 Format command execution time for 512-byte sectors (minutes)	18
4.2.3 General performance characteristics	18
4.3 Start/stop time	19
4.4 Prefetch/multi-segmented cache control	19
4.5 Cache operation	19
4.5.1 Caching write data	20
4.5.2 Prefetch operation	21
4.5.3 Optimizing cache performance for desktop and server applications	21
5.0 Reliability specifications	23
5.1 Error rates	23
5.1.1 Recoverable Errors	23
5.1.2 Unrecoverable Errors	23
5.1.3 Seek errors	24
5.1.4 Interface errors	24
5.2 Reliability and service	24
5.2.1 Mean time between failure	24
5.2.2 Preventive maintenance	24
5.2.3 Hot plugging the drive	25
5.2.4 S.M.A.R.T.	25
5.2.5 Thermal monitor	26
5.2.6 Drive Self Test (DST)	27
5.2.6.1 DST failure definition	27
5.2.6.2 Implementation	27
5.2.6.2.1 State of the drive prior to testing	28
5.2.6.2.2 Invoking DST	28
5.2.6.2.3 Short and extended tests	28
5.2.6.2.4 Log page entries	29
5.2.6.2.5 Abort	29
5.2.7 Product warranty	29
6.0 Physical/electrical specifications	31
6.1 AC power requirements	31
6.2 DC power requirements	31
6.2.1 Conducted noise immunity	33
6.2.2 Power sequencing	33
6.2.3 Current profiles	33
6.3 Power dissipation	36
6.4 Environmental limits	38
6.4.1 Temperature	38
6.4.2 Relative humidity	38
6.4.3 Effective altitude (sea level)	39
6.4.4 Shock and vibration	39
6.4.4.1 Shock	39
6.4.4.2 Vibration	41
6.4.5 Air cleanliness	41
6.4.6 Corrosive environment	41
6.4.7 Acoustics	42
6.4.8 Electromagnetic susceptibility	42
6.5 Mechanical specifications	43
7.0 Defect and error management	45
7.1 Drive internal defects/errors	45
7.2 Drive error recovery procedures	45
7.3 SAS system errors	46
8.0 Installation	47
8.1 Drive orientation	47
8.2 Cooling	48
8.3 Drive mounting	49
8.4 Grounding	49
9.0 Interface requirements	51
9.1 SAS features	51
9.1.1 task management functions	51
9.1.2 task management responses	51
9.2 Dual port support	52
9.3 SCSI commands supported	53
9.3.1 Inquiry data	57
9.3.2 Mode Sense data	57
9.4 Miscellaneous operating features and conditions	61
9.4.1 SAS physical interface	62
9.4.2 Physical characteristics	65
9.4.3 Connector requirements	65
9.4.4 Electrical description	65
9.4.5 Pin descriptions	65
9.4.6 SAS transmitters and receivers	66
9.4.7 Power	67
9.5 Signal characteristics	67
9.5.1 Ready LED Out	67
9.5.2 Differential signals	67
9.5.2.1 Eye masks	68
9.5.2.1.1 Eye masks overview	68
9.5.2.1.2 Receive eye mask	68
9.5.2.1.3 Jitter tolerance masks	69
9.5.2.2 Transmitter signal characteristics	71
9.5.2.3 Receiver signal characteristics	72
9.5.2.3.1 Jitter	72
9.5.2.3.2 Receiver jitter tolerance	73
9.5.2.3.3 Compliant jitter test pattern (CJTPAT)	73
9.5.2.3.4 Impedance specifications	73
9.5.2.4 Electrical TxRx connections	74
9.5.2.4.1 Transmitter characteristics	74
9.5.2.5 Receiver characteristics	77
10.0 Seagate Technology support services	79
Numerics	81
A	81
B	81
C	81
D	81
E	81
F	82
G	82
H	82
I	82
J	82
L	82
M	82
N	83
O	83
P	83
Q	83
R	83
S	83
T	84
U	84
V	84
W	84

Seagate ST300MM0026 Savvio 10K.1 SAS Product Manual - Page 26

Method of Reporting Informational Exceptions field MRIE on the Informational Exceptions Control IEC

Page 26 highlights