Seagate ST973451SS, ST936751SS manual SAS system errors

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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 4 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.

When the RC bit is one, reallocations are disabled even if the ARRE or AWRE bits are one. The drive will still perform data recovery actions within the limits defined by the Read Retry Count, Write Retry Count, and Recovery Time Limit parameters. However, the drive does not report any unrecovered errors.

Table 4: Read and write retry count maximum recovery times

 

Maximum recovery time per

Read retry count

LBA (cumulative, msec)

 

 

 

 

0

51.87

 

 

1

59.85

 

 

2

203.49

 

 

3

219.45

 

 

4

253.11

 

 

5

279.35

 

 

6

311.27

 

 

7

395.12

 

 

8

463.12

 

 

9

495.04

 

 

10

530.95

 

 

11 (default)

1,282.97

 

 

Write retry count

Maximum recovery time per

LBA (cumulative, msec)

 

 

 

 

0

23.94

 

 

1

35.91

 

 

2

55.86

 

 

3

67.83

 

 

4

119.79

 

 

5 (default)

147.72

 

 

Setting these retry counts to a value below the default setting could result in degradation of the unrecovered error rate. 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 set to 450. A four LBA Read command is allowed to take up to 253.11 msec recov- ery time for each block and a maximum of 450 msec recovery for all four blocks. If either of these limits is reached and a block has not yet been recovered, the command will end with Check Condition status and an unrecoverable read error will be reported.

7.3SAS system errors

Information on the reporting of operational errors or faults across the interface is given in the SAS Interface Manual. The SSP Response 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 SAS Interface Manual. Status reporting plays a role in systems error management and its use in that respect is described in sections where the various com- mands are discussed.

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Savvio 15K SAS Product Manual, Rev. B

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Contents Savvio 15K SAS 100407739 Rev. BPage Revision status summary sheet Savvio 15K SAS Product Manual, Rev. B Contents Defect and error management InstallationSeagate Technology support services Interface requirementsList of Figures Page Scope Savvio 15K SAS Product Manual, Rev. B Applicable standards and reference documentation StandardsElectromagnetic compatibility Electromagnetic susceptibilityElectromagnetic compliance Electromagnetic compliance for the European UnionAustralian C-Tick Korean MICReference documents European Union Restriction of Hazardous Substances RoHSSavvio 15K SAS Product Manual, Rev. B General description Performance Standard featuresMedia description Factory-installed accessories ReliabilityFormatted capacities Programmable drive capacityOptions Performance characteristics Internal drive characteristicsSeek performance characteristics Access time Gen 2.0 LP dataFormat command execution time General performance characteristicsCache operation Start/stop timePrefetch/multi-segmented cache control Caching write data Prefetch operationReliability specifications Error ratesRecoverable Errors Unrecoverable ErrorsReliability and service Seek errorsInterface errors Preventive maintenance4 S.M.A.R.T Controlling S.M.A.R.TPerformance impact Reporting controlTemperature Log Page 0Dh Predictive failuresThermal monitor Parameter Code DescriptionState of the drive prior to testing DST failure definitionImplementation Invoking DSTProduct warranty Short test Function Code 001bExtended test Function Code 010b Log page entriesShipping Product repair and return informationSavvio 15K SAS Product Manual, Rev. B Physical/electrical specifications AC power requirementsDC power requirements ST973451SS DC power requirementsST936751SS DC power requirements General DC power requirement notesCurrent profiles Power sequencingConducted noise immunity Typical ST936751SS current profile ST973451SS in 1.5 Gbit operation Power dissipationST973451SS in 3 Gbit operation ST936751SS in 3 Gbit operation ST936751SS in 1.5 Gbit operationRelative humidity TemperatureEnvironmental limits Shock Effective altitude sea levelShock and vibration Recommended mounting Corrosive environment Air cleanlinessVibration Acoustics Mechanical specifications Mounting configuration dimensionsDrive error recovery procedures Defect and error managementDrive internal defects/errors SAS system errors Deferred Auto-Reallocation Background Media ScanMedia Pre-Scan Idle Read After Write Installation Drive orientationCooling Air flowDrive mounting GroundingSavvio 15K SAS Product Manual, Rev. B SAS features Interface requirementsDual port support Scsi commands supported Commands supported by Savvio SAS family driveCommands supported by Savvio SAS family drive Commands supported by Savvio SAS family drive Commands supported by Savvio SAS family drive Savvio inquiry data Mode Sense dataInquiry data Page Mode Data Header 04 45 dc cc 00 00 02 Miscellaneous status Miscellaneous operating features and conditionsMiscellaneous features SAS physical interface Datum B Section C C Section a a Physical characteristics Connector requirementsElectrical description Pin descriptionsSAS pin descriptions SAS transmitters and receiversSignal characteristics Receive eye mask General interface characteristicsEye masks Eye masks overview Jitter tolerance masks Z1 OPTransmitter signal characteristics Peak-toSinusoidal JitterReceiver signal characteristics Compliant jitter test pattern Cjtpat Maximum allowable jitterReceiver jitter tolerance Impedance specifications Impedance requirements Sheet 1Electrical TxRx connections Transmitter characteristicsImpedance requirements Sheet 2 = -5,437dB Shows the zero-length test load Receiver characteristics Savvio 15K SAS Product Manual, Rev. B Seagate Technology support services InternetPresales Support Technical SupportData Recovery Services Call Center Toll-free Direct dial Warranty ServiceData Recovery Services Authorized Service Centers Index NumericsPage SAS See also cooling
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