Seagate ST2000NM0041, ST1000NM0001 Idle Read After Write, Protection Information PI, Levels of PI

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10.7Idle Read After Write

Idle Read After Write (IRAW) utilizes idle time to verify the integrity of recently written data. During idle periods, no active system requests, the drive reads recently written data from the media and compares it to valid write command data resident in the drives data buffer. Any sectors that fail the comparison result in the invocation of a rewrite and auto-reallocation process. The process attempts to rewrite the data to the original location. If a verification of this rewrite fails, the sector is re-mapped to a spare location.

10.8Protection Information (PI)

Protection Information is intended as a standardized approach to system level LRC traditionally provided by systems using 520 byte formatted LBAs. Drives formatted with PI information provide the same, common LBA count (i.e. same capacity point) as non-PI formatted drives. Sequential performance of a PI drive will be reduced by approximately 1.56% due to the extra overhead of PI being transferred from the media that is not calculated as part of the data transferred to the host. To determine the full transfer rate of a PI drive, transfers should be calculated by adding the 8 extra bytes of PI to the transferred LBA length, i.e. 512 + 8 = 520. PI for- matted drives are physically formatted to 520 byte sectors that store 512 bytes of customer data with 8 bytes of Protection Information appended to it. The advantage of PI is that the Protection Information bits can be man- aged at the HBA and HBA driver level. Allowing a system that typically does not support 520 LBA formats to integrate this level of protection.

Protection Information is valid with any supported LBA size. 512 LBA size is used here as common example.

10.8.1Levels of PI

There are 4 types of Protection Information.

Type 0 - Describes a drive that is not formatted with PI information bytes. This allows for legacy support in non- PI systems.

Type 1 - Provides support of PI protection using 10 and 16 byte commands. The RDPROTECT and WRTPRO- TECT bits allow for checking control through the CDB. Eight bytes of Protection Information are transmitted at LBA boundaries across the interface if RDPROTECT and WRTPROTECT bits are nonzero values. Type 1 does not allow the use of 32 byte commands.

Type 2 - Provides checking control and additional expected fields within the 32 byte CDBs. Eight bytes of Pro- tection Information are transmitted at LBA boundaries across the interface if RDPROTECT and WRTPRO- TECT bits are nonzero values. Type 2 does allow the use of 10 and 16 byte commands with zero values in the RDPROTECT and WRTPROTECT fields. The drive will generate 8 bytes (e.g.0xFFFF) 8 bytes of Protection Information to be stored on the media, but the 8 bytes will not be transferred to the host during a read com- mand.

Type 3 - Seagate products do not support Type 3.

10.8.2Setting and determining the current Type Level

A drive is initialized to a type of PI by using the format command on a PI capable drive. Once a drive is format- ted to a PI Type, it may be queried by a Read Capacity (16) command to report the PI type which it is currently formatted to. PI Types cannot coexist on a single drive. A drive can only be formatted to a single PI Type. It can be changed at anytime to a new Type but requires a low level format which destroys all existing data on the drive. No other vehicle for changing the PI type is provided by the T10 SBC3 specification.

Type 1 PI format CDB command:

04

90 00 00 00 00,

Write Buffer: 00 A0 00 00

Type 2 PI format CDB command:

04

D0 00 00 00 00,

Write Buffer: 00 A0 00 00

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Contents ST1000NM0041 ST500NM0041 Standard Models Self-Encrypting Drive ModelsSED Fips 140-2 Models ST2000NM0041 Revision history Contents Installation Defect and error managementAbout Fips About self-encrypting drives Interface requirementsPage Constellation ES.1 SAS Product Manual, Rev. E List of Figures Constellation ES.1 SAS Product Manual, Rev. E Seagate Online Support and Services Seagate Technology support servicesModel Number Self-Encrypting Drive SED Fips 140-2 Level ScopeStandards Applicable standards and reference documentationElectromagnetic compatibility Electromagnetic susceptibilityElectromagnetic compliance for the European Union Electromagnetic complianceAustralian C-Tick Korean KCCChina Restriction of Hazardous Substances RoHS Directive European Union Restriction of Hazardous Substances RoHSSelf-Encrypting Drives Reference Manual Reference documentsGeneral description Standard features Media descriptionPerformance Reliability Factory-installed optionsFormatted capacities Programmable drive capacityInternal drive characteristics Performance characteristicsSeek performance characteristics Access timeStart/stop time General performance characteristicsCache operation Prefetch/multi-segmented cache controlPrefetch operation Caching write dataError rates Reliability specificationsRecoverable Errors Unrecoverable ErrorsSeek errors Reliability and serviceInterface errors Preventive maintenanceControlling S.M.A.R.T 4 S.M.A.R.TPerformance impact Reporting controlTemperature Log Page 0Dh Parameter Code Description Predictive failuresThermal monitor Drive Self Test DST State of the drive prior to testingDST failure definition ImplementationShort test Function Code 001b Short and extended testsExtended test Function Code 010b Log page entriesShipping Product warrantyStorage Product repair and return informationPhysical/electrical specifications PowerChoiceTM power managementPowerChoice modes DC power requirements AC power requirementsRegulation ±5% Constellation ES.1 SAS Product Manual, Rev. E Constellation ES.1 SAS Product Manual, Rev. E General DC power requirement notes Power sequencingConducted noise immunity TB model current profiles Current profilesConstellation ES.1 SAS Product Manual, Rev. E GB model current profiles 2TB models in 3Gb operation Power dissipation2TB models in 6Gb operation 1TB models in 3Gb operation 1TB models in 6Gb operation 500GB models in 3Gb operation 500GB models in 6Gb operation Temperature a. Operating Environmental limitsRelative humidity Effective altitude sea level a. Operating Shock and vibrationShock Recommended mounting Vibration a. Operating-normalAir cleanliness AcousticsCorrosive environment Mounting configuration dimensions Mechanical specificationsPurpose About FipsValidation Program Seagate Enterprise SEDExample of Fips tamper evidence labels Admin SP Controlled accessAbout self-encrypting drives Data encryptionRandom number generator RNG Authenticated firmware downloadDrive locking Data bandsSupported commands Power requirementsSanitize Cryptographic Erase RevertSP Defect and error management Drive internal defects/errors Drive error recovery procedures SAS system errors Background Media Scan Media Pre-ScanDeferred Auto-Reallocation Idle Read After Write Setting and determining the current Type LevelProtection Information PI Levels of PIIdentifying a Protection Information drive Drive orientation InstallationAir flow CoolingGrounding Drive mountingInterface requirements SAS featuresDual port support Supported commands Scsi commands supportedSupported commands Supported commands Supported commands Mode Sense data Inquiry dataConstellation ES.1 inquiry data Page Mode Sense data changeable and default values for 2TB drives Mode Sense data changeable and default values for 1TB drives 3a 38 60 30 00 00 02 Miscellaneous operating features and conditions Miscellaneous featuresMiscellaneous status SAS physical interface Datum B Section C C Section a a Connector requirements Physical characteristicsElectrical description Pin descriptionsPower Signal characteristicsSAS transmitters and receivers Ready LED OutLED drive signal SAS-2 Specification ComplianceDifferential signals General interface characteristicsConstellation ES.1 SAS Product Manual, Rev. E Numerics IndexKCC Msid Mtbf See also cooling Page Constellation ES.1 SAS Product Manual, Rev. E Page Americas Seagate Technology LLC
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