Seagate ST400FX0002 Pulsar XT.2 SAS Product Manual - Page 25

Pulsar XT.2 SAS Product Manual, Rev. B

17

the static electricity from the drive carrier prior to inserting it into the system.

6.3.4

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 administrators to back up the data before an actual failure occurs.

Note.

The drive’s firmware monitors specific attributes for degradation over time but can’t predict instanta-

neous drive failures.

Each monitored attribute has been selected to monitor a specific set of failure conditions in the operating per-

formance of 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 and PERF bits on the Informational Exceptions

Control mode page (1Ch). Use the DEXCPT bit to enable or disable the S.M.A.R.T. feature. Setting the DEX-

CPT bit disables all S.M.A.R.T. functions. When enabled, S.M.A.R.T. collects on-line data as the drive performs

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.

An application 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 one hour.

An application can interrogate the drive through the host to determine the time remaining before the next

scheduled measurement and data logging process occurs. To accomplish this, issue a LOG SENSE command

to log page 0x3E. This allows applications to control when S.M.A.R.T. interruptions occur. Forcing S.M.A.R.T.

with the REZERO UNIT command resets the timer.

Performance impact

S.M.A.R.T. attribute data is saved to the media so that the events that caused a predictive failure can be recre-

ated. The drive measures and saves parameters once every hour subject to an idle period on the drive inter-

faces. The process of measuring off-line attribute data and saving data to the media is interruptible. The

maximum on-line only processing delay is summarized below

Reporting control

Reporting is controlled by the MRIE bits in the Informational Exceptions Control mode page (1Ch). Subject to

the reporting method. For example, if the MRIE is set to one, the firmware will issue to the host an 01-5D00

sense code. The FRU field contains the type of predictive failure that occurred. 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.

Maximum processing delay

Fully-enabled delay

DEXCPT = 0

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

75 ms

Section	Page
1.0 Seagate Technology support services	9
2.0 Scope	10
3.0 Applicable standards and reference documentation	11
3.1 Standards	11
3.1.1 Electromagnetic compatibility	11
3.1.1.1 Electromagnetic susceptibility	11
3.1.2 Electromagnetic compliance	12
3.1.3 European Union Restriction of Hazardous Substances (RoHS)	12
3.1.4 China Restriction of Hazardous Substances (RoHS) Directive	13
3.2 Reference documents	13
4.0 General description	14
4.1 Standard features	14
4.2 Media description	15
4.3 Performance	15
4.4 Reliability	15
4.5 Formatted capacities	16
4.6 Programmable drive capacity	16
4.7 Factory-installed options	16
4.8 Thin Provisioning	17
4.8.1 Logical Block Provisioning	17
4.8.2 Thin Provisioning capabilities	17
4.8.3 UNMAP	17
4.8.4 FORMAT UNIT command	17
4.8.5 Protection Information (PI) and Security (SED)	17
5.0 Performance characteristics	19
5.1 Internal drive characteristics	19
5.2 Performance characteristics	19
5.2.1 Access time	19
5.2.2 FORMAT UNIT command execution time for 512-byte LBA’s (minutes)	20
5.2.3 Performance	20
5.3 Start/stop time	21
5.4 Cache control	21
5.4.1 Caching write data	21
6.0 Reliability specifications	22
6.1 Error rates	22
6.1.1 Unrecoverable Errors	23
6.1.2 Interface errors	23
6.2 Endurance Management	23
6.2.1 Wear Leveling	23
6.2.2 Garbage Collection	23
6.2.3 Write Amplification	23
6.2.4 UNMAP	23
6.2.5 Data Retention	24
6.2.6 Lifetime Endurance Management	24
6.3 Reliability and service	24
6.3.1 Annualized Failure Rate (AFR) and Mean Time Between Failure (MTBF)	24
6.3.2 Preventive maintenance	24
6.3.3 Hot plugging the drive	24
6.3.4 S.M.A.R.T.	25
6.3.5 Thermal monitor	26
6.3.6 Drive Self Test (DST)	27
6.3.6.1 DST failure definition	27
6.3.6.2 Implementation	27
6.3.7 Product warranty	29
7.0 Physical/electrical specifications	30
7.1 Power specifications	30
7.1.1 Power consumption	30
7.2 AC power requirements	30
7.3 DC power requirements	31
7.3.1 Conducted noise immunity	34
7.3.2 Power sequencing	34
7.3.3 Current profiles	34
7.4 Power dissipation	36
7.5 Environmental limits	37
7.5.1 Temperature	37
7.5.2 Relative humidity	38
7.5.3 Effective altitude (sea level)	38
7.5.4 Shock and vibration	38
7.5.4.1 Shock	39
7.5.4.2 Vibration	40
7.5.5 Air cleanliness	40
7.5.6 Corrosive environment	40
7.5.7 Electromagnetic susceptibility	40
7.6 Mechanical specifications	41
8.0 About self-encrypting drives	43
8.1 Data encryption	43
8.2 Controlled access	43
8.2.1 Admin SP	43
8.2.2 Locking SP	44
8.2.3 Default password	44
8.3 Random number generator (RNG)	44
8.4 Drive locking	44
8.5 Data bands	44
8.6 Cryptographic erase	45
8.7 Authenticated firmware download	45
8.8 Power requirements	45
8.9 Supported commands	45
8.10 RevertSP	45
9.0 Defect and error management	46
9.1 Drive internal defects/errors	46
9.2 Drive error recovery procedures	47
9.3 SAS system errors	47
9.4 Background Media Scan	47
9.5 Auto-Reallocation	47
9.6 Protection Information (PI)	48
9.6.1 Levels of PI	48
9.6.2 Setting and determining the current Type Level	48
9.6.3 Identifying a Protection Information drive	48
10.0 Installation	49
10.1 Drive orientation	49
10.2 Cooling	50
10.3 Drive mounting	51
10.4 Grounding	51
11.0 Interface requirements	52
11.1 SAS features	52
11.1.1 Task management functions	52
11.1.2 Task management responses	52
11.2 Dual port support	53
11.3 SCSI commands supported	54
11.3.1 INQUIRY data	58
11.3.2 MODE SENSE data	58
11.4 Miscellaneous operating features and conditions	63
11.4.1 SAS physical interface	63
11.4.2 Physical characteristics	66
11.4.3 Connector requirements	66
11.4.4 Electrical description	66
11.4.5 Pin descriptions	66
11.4.6 SAS transmitters and receivers	67
11.4.7 Power	67
11.5 Signal characteristics	67
11.5.1 Ready LED Out	67
11.5.2 Differential signals	68
11.6 SAS-2 Specification compliance	68
11.7 Additional information	68
Numerics	69
A	69
B	69
C	69
D	69
E	69
F	70
G	70
H	70
I	70
J	70
L	70
M	70
N	71
O	71
P	71
Q	71
R	71
S	71
T	72
U	72
V	72
W	72

Seagate ST400FX0002 Pulsar XT.2 SAS Product Manual - Page 25

S.M.A.R.T., Controlling S.M.A.R.T., Performance impact, Reporting control, Determining rate

Page 25 highlights