Seagate ST300MM0026 Savvio 10K.1 SAS Product Manual - Page 45

Savvio SAS Product Manual, Rev. D

39

7.0

Defect and error management

The drive, as delivered, complies with this product manual. The read error rates and specified storage capaci-

ties are not dependent upon use of defect management routines by the host (initiator).

Defect and error management in the SCSI protocol involves the drive internal defect/error management and

SAS system error considerations (errors in communications between the initiator and the drive). Tools for use

in designing a defect/error management plan are briefly outlined in this section. References to other sections

are provided when necessary.

7.1

Drive internal defects/errors

During the initial drive format operation at the factory, media defects are identified, tagged as being unusable,

and their locations recorded on the drive primary defects list (referred to as the “P’ list and also as the ETF

defect list). At factory format time, these known defects are also reallocated, that is, reassigned to a new place

on the medium and the location listed in the defects reallocation table. The “P” list is not altered after factory

formatting. Locations of defects found and reallocated during error recovery procedures after drive shipment

are listed in the “G” list (defects growth list). The “P” and “G” lists may be referenced by the initiator using the

Read Defect Data command.

Details of the SCSI commands supported by the drive are described in the

SAS Interface Manual

. Also, more

information on the drive Error Recovery philosophy is presented in the


.

7.2

Drive error recovery procedures

When an error occurs during drive operation, the drive, if programmed to do so, performs error recovery proce-

dures to attempt to recover the data. The error recovery procedures used depend on the options previously set

in the Error Recovery Parameters mode page. Error recovery and defect management may involve using sev-

eral SCSI commands described in the


. The drive implements selectable error recovery

time limits required in video applications.

The error recovery scheme supported by the drive provides a way to control the total error recovery time for the

entire command in addition to controlling the recovery level for a single LBA. The total amount of time spent in

error recovery for a command can be limited using the Recovery Time Limit bytes in the Error Recovery mode

page. The total amount of time spent in error recovery for a single LBA can be limited using the Read Retry

Count or Write Retry Count bytes in the Error Recovery mode page.

The drive firmware error recovery algorithms consists of 11 levels for read recoveries and five levels for write.

Each level may consist of multiple steps, where a step is defined as a recovery function involving a single re-

read or re-write attempt. The maximum level used by the drive in LBA recovery is determined by the read and

write retry counts.

Table 14 equates the read and write retry count with the maximum possible recovery time for read and write

recovery of individual LBAs. The times given do not include time taken to perform reallocations. Reallocations

are performed when the ARRE bit (for reads) or AWRE bit (for writes) is one, the RC bit is zero, and the recov-

ery time limit for the command has not yet been met. Time needed to perform reallocation is not counted

against the recovery time limit.

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 45

Defect and error management

Page 45 highlights