Seagate ST9900805SS Savvio 10K.1 SCSI Product Manual - Page 44

38

Savvio SCSI Product Manual, Rev. D

used when data integrity is not a concern and speed is of utmost importance. If the Recovery Time Limit or

retry count is reached during error recovery, the state of the RC bit is examined. If the RC bit is set, the drive

will transfer the unrecovered data with no error indication and continue to execute the remaining command. If

the RC bit is not set, the drive will stop data transfer with the last good LBA, and report a “Check Condition,

Unrecovered Read Error.”

[1]

These values are subject to change.

Setting these retry counts to a value below the default setting could result in an increased unrecovered

error rate which may exceed the value given in this product manual. A setting of zero (0) will result in the

drive not performing error recovery.

For example, suppose the Read/Write Recovery page has the RC bit set to 0, read retry count set to 4,

and the recovery time limit field (Mode Sense page 01, bytes 10 and 11) set to FF FF hex (maximum). A

four LBA Read command is allowed to take up to 401

msec recovery time for each of the four LBAs in the

command. If the recovery time limit is set to 00 C8 hex (200 msec decimal) a four LBA read command is

allowed to take up to 200 msec for all error recovery within that command. The use of the Recovery Time

Limit field allows finer granularity on control of the time spent in error recovery. The recovery time limit

only starts counting when the drive is executing error recovery and it restarts on each command. There-

fore, each command’s total recovery time is subject to the recovery time limit. Note: A recovery time limit

of 0 will use the drive’s default value of FF FF. Minimum recovery time limit is achieved by setting the

Recovery Time Limit field to 00 01.

7.3

SCSI systems errors

Information on the reporting of operational errors or faults across the interface is given in the

SCSI Interface

Product Manual

. Message Protocol System is described in the

SCSI Command Reference Manual

. Several of

the messages are used in the SCSI systems error management system. The Request Sense command

returns information to the host about numerous kinds of errors or faults. The Receive Diagnostic Results

reports the results of diagnostic operations performed by the drive.

Status returned by the drive to the Initiator is described in the

SCSI Interface Product Manual

. Status reporting

plays a role in the SCSI systems error management and its use in that respect is described in sections where

the various commands are discussed.

Table 3:

Read and write retry count maximum recovery times [1]

Read retry

count [1]

Maximum recovery time per

LBA (cumulative, msec)

Write retry

count

Maximum recovery time per

LBA (cumulative, msec)

0

77.7

0

35.9

1

89.7

1

53.8

2

305

2

83.7

3

353

3

101.7

4

401

4

179.4

5

419

5 (default)

221.3

6

466

7

586

8

676

9

724

10

777

11 (default)

1,591

Section	Page
1.0 Scope	7
2.0 Applicable standards and reference documentation	9
2.1 Standards	9
2.1.1 Electromagnetic compatibility	9
2.1.2 Electromagnetic susceptibility	9
2.2 Electromagnetic compliance	10
2.3 Reference documents	11
3.0 General description	13
3.1 Standard features	14
3.2 Media characteristics	14
3.3 Performance	14
3.4 Reliability	15
3.5 Formatted capacities	15
3.5.1 Programmable drive capacity	15
3.6 Factory installed accessories	15
3.7 Options (factory installed)	16
3.8 Accessories (user installed)	16
4.0 Performance characteristic	17
4.1 Internal drive characteristics (transparent to user)	17
4.2 SCSI performance characteristics (visible to user)	17
4.2.1 Access time [5]	17
4.2.2 Format command execution time (minutes) [1]	17
4.2.3 Generalized performance characteristics	18
4.3 Start/stop time	18
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	20
4.5.3 Optimizing cache performance for desktop and server applications	20
5.0 Reliability specifications	23
5.1 Error rates	23
5.1.1 Environmental interference	23
5.1.2 Read errors	24
5.1.3 Write errors	24
5.1.4 Seek errors	24
5.2 Reliability and service	24
5.2.1 Mean time between failure	24
5.2.2 Preventive maintenance	25
5.2.3 Service life	25
5.2.4 Service philosophy	25
5.2.5 Service tools	25
5.2.6 Hot plugging Savvio SCSI disc drives	25
5.2.7 S.M.A.R.T.	26
5.2.8 Thermal monitor	27
5.2.9 Drive Self Test (DST)	28
5.2.9.1 DST Failure Definition	28
5.2.9.2 Implementation	28
5.2.9.2.1 State of the drive prior to testing	28
5.2.9.2.2 Invoking DST	29
5.2.9.2.3 Short and extended tests	29
5.2.9.2.4 Log page entries	29
5.2.9.2.5 Abort	30
5.2.10 Product warranty	30
6.0 Physical/electrical specifications	31
6.1 AC power requirements	31
6.2 DC power requirements	31
6.2.1 Conducted noise immunity	32
6.2.2 Power sequencing	32
6.2.3 12 V - Current profile	32
6.3 Power dissipation	35
6.4 Environmental limits	37
6.4.1 Temperature	37
6.4.2 Relative humidity	38
6.4.3 Effective altitude (sea level)	38
6.4.4 Shock and vibration	38
6.4.4.1 Shock	38
6.4.4.2 Vibration	40
6.4.5 Air cleanliness	40
6.4.6 Corrosive environment	40
6.4.7 Acoustics	41
6.4.8 Electromagnetic susceptibility	41
6.5 Mechanical specifications	41
7.0 Defect and error management	43
7.1 Drive internal defects	43
7.2 Drive error recovery procedures	43
7.3 SCSI systems errors	44
8.0 Installation	45
8.1 Drive orientation	45
8.2 Cooling	45
8.3 Drive mounting	46
8.4 Grounding	46
9.0 Interface requirements	47
9.1 General description	47
9.2 SCSI interface messages supported	48
9.3 SCSI interface commands supported	49
9.3.1 Inquiry Vital Product data	53
9.3.2 Mode Sense data	53
9.4 SCSI bus conditions and miscellaneous features supported	57
9.5 Synchronous data transfer	57
9.5.1 Synchronous data transfer periods supported	58
9.5.2 REQ/ACK offset	58
9.6 Physical interface	58
9.6.1 DC cable and connector	58
9.6.2 SCSI interface physical description	59
9.6.3 SCSI interface cable requirements	60
9.6.3.1 Cable requirements	60
9.6.4 Mating connectors	60
9.6.4.1 Mating connectors	60
9.7 Electrical description	64
9.7.1 Multimode-SE and LVD alternatives	64
9.7.1.1 General cable characteristics	65
9.7.1.2 Single-ended drivers/receivers	65
9.8 Terminator requirements	65
9.8.1 Terminator power	65
9.9 Disc drive SCSI timing	66

Seagate ST9900805SS Savvio 10K.1 SCSI Product Manual - Page 44

SCSI systems errors

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