Seagate ST100FX0002, ST200FX0002, ST400FX0012, ST400FX0002 Protection Information PI, Levels of PI

Page 48

9.6Protection 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 LBA’s 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.

9.6.1Levels 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 of Protection Information (e.g. 0xFFFFFFFF) to be stored on the media, but the 8 bytes will not be transferred to the host during a READ command.

Type 3 - Seagate products do not support Type 3.

9.6.2Setting and determining the current Type Level

A drive is initialized to a type of PI by using the FORMAT UNIT command on a PI capable drive. Once a drive is formatted 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. A drive can only be formatted to a single PI Type. It can be changed at anytime to a new Type but requires a FORMAT UNIT command which destroys all existing data on the drive. No other vehi- cle for changing the PI type is provided by the T10 SBC3 specification.

Type 1 PI FORMAT UNIT CDB command: 04 90 00 00 00 00, parameter data: 00 A0 00 00

Type 2 PI FORMAT UNIT CDB command: 04 D0 00 00 00 00, parameter data: 00 A0 00 00

9.6.3Identifying a Protection Information drive

The Standard INQUIRY data provides a bit to indicate if PI is support by the drive. Vital Product Descriptor (VPD) page 0x86 provides bits to indicate the PI Types supported and which PI fields the drive supports check- ing.

Note. For further details with respect to PI, please refer to SCSI Block Commands - 3 (SBC-3) Draft Stan- dard documentation.

40

Pulsar XT.2 SAS Product Manual, Rev. B

Page 47 Page 49
Image 48
Page 47 Page 49
Contents ST400FX0002ST400FX0012 ST200FX0002 ST100FX0002 Standard Models Self-Encrypting Drive ModelsRevision history Contents Physical/electrical specifications Defect and error managementInstallation About self-encrypting drivesPage Pulsar XT.2 SAS Product Manual, Rev. B List of Figures Page Seagate Technology support services Seagate Online Support and ServicesScope Applicable standards and reference documentation StandardsElectromagnetic compatibility Electromagnetic susceptibilityElectromagnetic compliance Electromagnetic compliance for the European UnionAustralian C-Tick Korean KCCReference documents China Restriction of Hazardous Substances RoHS DirectiveStandard features General descriptionMedia description PerformanceReliability Factory-installed options Formatted capacitiesProgrammable drive capacity Thin Provisioning Drive Configuration Performance characteristics Internal drive characteristicsPerformance characteristics Access timeFormat Mode Dcrt Bit IP Bit 400GB 200GB 100GB PerformanceStart/stop time Cache controlCaching write data Reliability specifications Error ratesEndurance Management Reliability and service Preventive maintenanceData Retention Lifetime Endurance ManagementMaximum processing delay Fully-enabled delay 4 S.M.A.R.TControlling S.M.A.R.T Performance impactPredictive failures Thermal monitorState of the drive prior to testing Drive Self Test DSTDST failure definition ImplementationShort and extended tests Short test Function Code 001bExtended test Function Code 010b Log page entriesProduct warranty ShippingProduct repair and return information StoragePhysical/electrical specifications Power specificationsAC power requirements DC power requirements 400GB standard model DC power requirements200GB standard model DC power requirements 100GB standard model DC power requirements General DC power requirement notes Power sequencingConducted noise immunity Current profilesCurrent profiles for 200GB models Power dissipation 400GB models in 6Gb operation200GB models in 6Gb operation Temperature a. Operating Environmental limits100GB models in 6Gb operation Relative humidity Effective altitude sea level a. OperatingShock and vibration Shock Recommended mountingAir cleanliness Vibration a. Operating-normalCorrosive environment Mechanical specifications Mounting configuration dimensions 400GB modelsWeight Pounds 100 grams Controlled access Admin SPAbout self-encrypting drives Data encryptionDefault password Random number generator RNGDrive locking Data bandsAuthenticated firmware download Power requirementsSupported commands Cryptographic eraseDefect and error management Drive internal defects/errorsSSD Physical format address descriptor Bit Byte Drive error recovery procedures SAS system errorsBackground Media Scan Auto-ReallocationSetting and determining the current Type Level Protection Information PILevels of PI Identifying a Protection Information driveInstallation Drive orientationCooling Air flowDrive mounting GroundingSAS features Interface requirementsDual port support Scsi commands supported Supported commandsPersistent Reserve Read Capacity Write Mode Sense data Inquiry dataPage Mode Sense data for 400GB drives 14 1a 00 1aMode Sense data for 200GB drives Mode PagesMode Sense values for 100GB drives Miscellaneous operating features and conditions Miscellaneous featuresMiscellaneous status SAS physical interfaceDatum B Section C C Section a a Physical characteristics Connector requirementsElectrical description Pin descriptionsSignal characteristics PowerSAS transmitters and receivers Ready LED OutSAS-2 Specification compliance LED drive signalDifferential signals General interface characteristicsIndex NumericsPage RNG See also cooling Page Seagate Technology LLC Americas
Top Page Image Contents