Seagate ST3450856FC, ST3146356FC, ST3300656FC manual Media Pre-Scan, Deferred Auto-Reallocation

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service by the host system. On regular duty drives, if the host system makes use of the BMS Log Page, it can avoid placing data in suspect locations on the media. Unreadable and recovered error sites will be logged or reallocated per ARRE/AWRE settings.

With BMS, the host system can consume less power and system overhead by only checking BMS status and results rather than tying up the bus and consuming power in the process of host-initiated media scanning activ- ity.

Since the background scan functions are only done during idle periods, BMS causes a negligible impact to sys- tem performance. The first BMS scan for a newly manufactured drive is performed as quickly as possible to verify the media and protect data by setting the “Start time after idle” to 5ms, all subsequent scans begin after 500ms of idle time. Other features that normally use idle time to function will function normally because BMS functions for bursts of 800ms and then suspends activity for 100ms to allow other background functions to operate.

BMS interrupts immediately to service host commands from the interface bus while performing reads. BMS will complete any BMS-initiated error recovery prior to returning to service host-initiated commands. Overhead associated with a return to host-servicing activity from BMS only impacts the first command that interrupted BMS, this results in a typical delay of about 1 ms.

7.5Media Pre-Scan

Media Pre-Scan is a feature that allows the drive to repair media errors that would otherwise have been found by the host system during critical data accesses early in the drive’s life. The default setting for Media Pre-Scan is enabled on standard products. Media Pre-Scan checks each write command to determine if the destination LBAs have been scanned by BMS. If the LBAs have been verified, the drive proceeds with the normal write command. If the LBAs have not been verified by BMS, Pre-Scan will convert the write to a write verify to certify that the data was properly written to the disc.

Note. During Pre-Scan write verify commands, write performance may decrease by 50% until Pre-Scan completes. Write performance testing should be performed after Pre-Scan is complete. This may be checked by reading the BMS status.

To expedite the scan of the full pack and subsequently exit from the Pre-Scan period, BMS will begin scanning immediately when the drive goes to idle during the Pre-Scan period. In the event that the drive is in a high transaction traffic environment and is unable to complete a BMS scan within 24 power on hours BMS will dis- able Pre-Scan to restore full performance to the system.

7.6Deferred Auto-Reallocation

Deferred Auto-Reallocation (DAR) simplifies reallocation algorithms at the system level by allowing the drive to reallocate unreadable locations on a subsequent write command. Sites are marked for DAR during read oper- ations performed by the drive. When a write command is received for an LBA marked for DAR, the auto-reallo- cation process is invoked and 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.

This is in contrast to the system having to use the Reassign Command to reassign a location that was unread- able and then generate a write command to rewrite the data. DAR is most effective when AWRE and ARRE are enabled—this is the default setting from the Seagate factory. With AWRE and ARRE disabled DAR is unable to reallocate the failing location and will report an error sense code indicating that a write command is being attempted to a previously failing location.

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Cheetah 15K.6 FC Product Manual, Rev. A

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Contents Cheetah 15K.6 FC ST3450856FC ST3300656FC ST3146356FCPage Contents Interface requirements Defect and error managementInstallation Seagate Technology support services Cheetah 15K.6 FC Product Manual, Rev. a List of Figures Page Scope Cheetah 15K.6 FC Product Manual, Rev. a Electromagnetic compatibility Applicable standards and reference documentationStandards Electromagnetic susceptibilityEuropean Union Restriction of Hazardous Substances RoHS Reference documents Ncits TR-20Cheetah 15K.6 FC Product Manual, Rev. a General description Standard features Media descriptionReliability Factory-installed optionsPerformance Formatted capacitiesUser-installed accessories Seek performance characteristics Performance characteristicsInternal drive characteristics Access timeStart/stop time Format command execution time minutesGeneral performance characteristics Prefetch/multi-segmented cache controlCache operation Caching write dataPrefetch operation Recoverable Errors Reliability specificationsError rates Unrecoverable ErrorsInterface errors Reliability and serviceSeek errors Preventive maintenancePerformance impact 4 S.M.A.R.TControlling S.M.A.R.T MillisecondsPredictive failures Reporting controlDetermining rate Thermal monitorDrive Self Test DST State of the drive prior to testingParameter Code Description DST failure definitionShort test Function Code 001b Invoking DSTShort and extended tests Extended test Function Code 010bShipping Product warrantyAbort Product repair and return informationCheetah 15K.6 FC Product Manual, Rev. a DC power requirements Physical/electrical specificationsAC power requirements DC power requirements for ST3450856FC model Gbit AmpsDC power requirements for ST3300656FC model Gbit Amps DC power requirements for ST3146356FC model Gbit AmpsConducted noise immunity General DC power requirement notesPower sequencing Current profilesTypical ST3450856FC current profiles Typical ST3300656FC current profiles Typical ST3146356FC current profiles Power dissipation ST3450856FCST3300656FC ST3146356FC TemperatureEnvironmental limits Shock and vibration Relative humidityEffective altitude sea level ShockPackage size Packaged/product weight Drop height Recommended mounting Acoustics Air cleanlinessVibration Corrosive environmentRoHS compliance statement Mechanical specifications Mounting configuration dimensionsCheetah 15K.6 FC Product Manual, Rev. a Drive error recovery procedures Defect and error managementDrive internal defects/errors Page FC-AL system errors Background Media ScanMedia Pre-Scan Deferred Auto-ReallocationIdle Read After Write Cheetah 15K.6 FC Product Manual, Rev. a Drive orientation InstallationDrive ID/option selection CoolingDrive mounting Air flowGrounding Cheetah 15K.6 FC Product Manual, Rev. a Link services supported Type of frame FC-AL featuresFibre Channel link service frames Interface requirementsFC Scsi FCP response codes Function name Response code Fibre Channel task management functionsFibre Channel task management responses Fibre Channel port login NPort login Plogi payload BytesNPort Login Accept ACC payload Bytes Fibre Channel port login acceptFibre Channel Process Login Process Login Plri payloadProcess Login Accept ACC payload Bytes Fibre Channel Process Login AcceptFibre Channel fabric login Fabric Login Flogi payload BytesFibre Channel fabric accept login Fabric Login Accept ACC payload BytesFC-AL options supported Dual port supportFibre Channel Arbitrated Loop options Option SupportedScsi commands supported Supported commands Command code Command nameVerify error recovery page 07h Cheetah 15K.6 FC Product Manual, Rev. a Temperature page 0Dh Cheetah 15K.6 FC inquiry data Bytes Data hex Mode Sense dataInquiry data Page Mode Data Header 000000 Cheetah 15K.6 FC Product Manual, Rev. a Supported Feature or condition Miscellaneous operating features and conditionsMiscellaneous features Miscellaneous statusPhysical description Physical characteristicsFC-AL physical interface Pin descriptions Connector requirementsElectrical description FC-AL transmitters and receivers FC-SCA pin descriptions Pin Signal name Signal typePin Signal name Signal type Power Fault LED OutMotor start controls Enable port bypass signalsActive LED Out Parallel Enclosure Services Interface ESI 11 SEL6 through SEL0 ID linesHex Dec SettingArbitrated loop physical address Alpa values Device control codes Signal characteristicsTTL input characteristics FC Differential input LED driver signalsFC Differential output Receive eye diagram Eye diagram data values Link rate GHz Cheetah 15K.6 FC Product Manual, Rev. a Presales Support Seagate Technology support servicesInternet Technical SupportData Recovery Services Call Center Toll-free Direct dial Warranty ServiceData Recovery Services Authorized Service Centers Index NumericsFAN Flogi Plogi Page See also cooling
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ST3450856FC, ST3300656FC, ST3146356FC specifications

The Seagate ST3146356FC, ST3300656FC, and ST3450856FC are hard disk drives designed for enterprise storage solutions, showcasing Seagate’s commitment to performance, reliability, and advanced technology in the data storage sector. These drives cater primarily to the needs of data centers and businesses requiring robust data management capabilities.

The ST3146356FC is notable for its 146GB capacity, 3.5-inch form factor, and 10,000 RPM spindle speed. It employs Serial Attached SCSI (SAS) interface technology, which ensures high data transfer rates and reliable connectivity. This model is designed to handle a multitude of demanding applications, such as online transaction processing and enterprise resource planning, requiring fast access to data and minimized latency.

The ST3300656FC, with a capacity of 300GB, continues the trend of high performance set by its predecessor. This drive also features the 10,000 RPM spindle speed and SAS interface, providing enhanced data throughput and optimized performance for intensive workloads. The drive is built with advanced error recovery features that enhance data integrity and reliability, making it suitable for critical applications where data loss is unacceptable.

The ST3450856FC offers even greater capacity, with a robust 450GB storage option. Like the other models, it operates at 10,000 RPM and utilizes the SAS interface. This drive is designed for scalability, ensuring that it can meet the evolving storage demands of enterprises. It is also equipped with sophisticated technologies such as Seagate's Enhanced S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology), providing continual monitoring of the drive’s health and performance metrics.

All three models share key characteristics, including advanced thermal and power management technologies that help maintain optimal operating temperatures and reduce energy consumption. This is crucial in data center environments where maximizing efficiency is vital for operational cost management. Additionally, Seagate's commitment to low acoustic noise levels ensures quieter operation, which is beneficial in environments where sound levels must be controlled.

In summary, the Seagate ST3146356FC, ST3300656FC, and ST3450856FC drives are engineered for enterprise environments demanding high reliability, speed, and capacity. Their advanced technologies, including SAS interface and enhanced error management systems, make these drives ideal for critical applications in data-intensive sectors. With reinforced durability, effectiveness in managing large volumes of data, and a focus on energy efficiency, these drives symbolize the pinnacle of Seagate's storage innovations for enterprise solutions.
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