Seagate ST300MM0026 Savvio 10K.1 SAS Product Manual - Page 25

Savvio SAS Product Manual, Rev. D

19

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 complete stop prior to changing the plane of operation. This time is

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 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.

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 the host to determine the time remaining before the next scheduled mea-

surement and data logging process occurs. To accomplish this, issue 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 recre-

ated. 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

On-line only delay

DEXCPT = 0, PERF = 1

Fully-enabled delay

DEXCPT = 0, PERF = 0

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

50 milliseconds

300 milliseconds

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 25

This allows you to control when S.M.A.R.T. interruptions occur. Forcing S.M.A.R.T. with the RTZ

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