Seagate ST800FM0002 manual Wear Leveling, Garbage Collection, Write Amplification, Data Retention

Page 20

5.2ENDURANCE MANAGEMENT

Customer satisfaction with Solid State Drives can be directly related to the internal algorithms which an SSD uses to manage the limited number of Program-Erase (PE) cycles that NAND Flash can withstand. These algorithms consist of Wearleveling, Garbage Collection, Write Amplification, Unmap, Data Retention, Lifetime Endurance Management.

5.2.1Wear Leveling

Wear Leveling is a technique used by the drive to ensure that all Flash cells are written to or exercised as evenly as possible to avoid any hot spots where some cells are used up faster than other locations. Wear Leveling is automatically managed by the drive and requires no user interaction. The Seagate algorithm is tuned to operate only when needed to ensure reliable product operation.

5.2.2Garbage Collection

Garbage Collection is a technique used by the drive to consolidate valid user data into a common cell range freeing up unused or obsolete locations to be erased and used for future storage needs. Garbage Collection is automatically managed by the drive and requires no user interaction. The Seagate algorithm is tuned to operate only when needed to ensure reliable product operation.

5.2.3Write Amplification

While Write Amplification is not an algorithm, it is a major characteristic of SSD's that must be accounted for by all the algorithms that the SSD implements. The Write Amplification Factor of an SSD is defined as the ratio of Host/User data requested to be written to the actual amount of data written by the SSD internal to account for the user data and the housekeeping activities such as Wear Leveling and Garbage Collection. The Write Amplification Factor of an SSD can also be directly affected by the characteristics of the host data being sent to the SSD to write. The best Write Amplification Factor is achieved for data that is written in sequential LBA's that are aligned on 4KB boundaries. The worst case Write Amplification Factor typically occurs for randomly written LBA's of transfer sizes that are less than 4KB and that originate on LBA's that are not on 4KB boundaries.

5.2.4UNMAP

A new SCSI command has been added to the SSD as part of the Thin Provisioning feature set. Use of the UNMAP command reduces the Write Amplification Factor of the drive during housekeeping tasks such as Wear Leveling and Garbage Collection. This is accomplished because the drive does not need to retain data which has been classified by the host as obsolete.

5.2.5Data Retention

Data Retention is another major characteristic of SSD's that must be accounted for by all the algorithms that the SSD implements. While powered up, the Data Retention of SSD cells are monitored and rewritten if the cell levels decay to an unexpected level. Data Retention when the drive is powered off is affected by Program and Erase (PE) cycles and the temperature of the drive when stored.

5.2.6Lifetime Endurance Management (Available on select models)

As stated in Section 5.2, an SSD has a limited number of Program and Erase (PE) cycles that are capable. In worse case applications, the write workload could be such that the drive experiences a high Write Amplification Factor that could lead to potential wear out prior to the drive achieving it's expected field life. Additionally, the Data Retention spec of the SSD needs to be considered to ensure the spec is met once the drive is worn out. Seagate has implemented a Lifetime Endurance Management technique which helps OEMS and user to avoid early wear out. By monitoring the write workload being sent to the drive, the drive can add additional response time to WRITE commands to provide a sustainable level of performance that is capable of being sustained for the life of the drive. Most users may never see this added response time in their applications.

5.2.7SSD Percentage Used Endurance Indicator

An application can interrogate the drive through the host to determine an estimate of the percentage of device life that has been used. To accomplish this, issue a LOG SENSE command to log page 0x11. This allows applications to read the contents of the Percentage Used Endurance Indicator parameter code. The Percentage Used Endurance Indicator is defined in the T10 document SBC-3 available from the T10 committee.

PULSAR.2 SAS PRODUCT MANUAL, REV. C

14

Page 19 Page 21
Image 20
Page 19 Page 21
Contents Pulsar.2 SAS Document Revision History Revision Date Description of changesContents PHYSICAL/ELECTRICAL Specifications Defect and Error ManagementInstallation About Fips About SELF-ENCRYPTING DrivesInterface Requirements Figures Seagate Technology Support Services Scope Standard models Standard SED models Fips 140-2 LevelElectromagnetic susceptibility Applicable Standards and Reference DocumentationElectromagnetic compatibility Electromagnetic compliance Electromagnetic compliance for the European UnionAustralian C-Tick Korean KCCChina Restriction of Hazardous Substances RoHS Directive General Description 800GB 400GB 200GB 100GB 512520 524Thin Provisioning capabilities Thin Provisioning Product ConfigurationLogical Block Provisioning Format Unit command PI and SED Drive ConfigurationUnmap Protection Information PI and Security SEDPerformance Characteristics Format Mode Dcrt Bit IP Bit 800GB 400GB 200GB 100GBAccess time Typical Access Time μsecPerformance Managed Life Warranty Performance Usage Based WarrantyST800FM00 ST400FM00 ST200FM00 ST100FM00 PerformanceCaching write data Interface errors Reliability SpecificationsUnrecoverable Errors SSD Percentage Used Endurance Indicator Wear LevelingGarbage Collection Write AmplificationPreventive maintenance Hot plugging the drive4 S.M.A.R.T Controlling S.M.A.R.TPerformance impact Reporting controlDetermining rate Predictive failuresTemperature Log Page 0Dh Parameter Code Description 800/400/200/100GBProduct warranty Managed Life WarrantyUsage Based Warranty Extended test Function Code 010bPHYSICAL/ELECTRICAL Specifications Power consumptionStartup power Peak operating mode800GB standard model DC power requirements 800GB 6.0GB400GB standard model DC power requirements 400GB 6.0GB200GB standard model DC power requirements 200GB 6.0GB100GB standard model DC power requirements General DC power requirement notesCurrent profiles Power sequencingConducted noise immunity Current profiles for 400GB models Current profiles for 100GB models 200GB models in 6Gb operation 800GB models in 6Gb operation400GB models in 6Gb operation 100GB models in 6Gb operation Environmental LimitsEffective altitude sea level a. Operating Temperature a. OperatingRelative humidity Shock and vibration ShockCorrosive environment Air cleanlinessVibration Weight Pounds 160 grams Weight Pounds 100 grams Purpose Validation ProgramSeagate Enterprise SED Security LevelAdmin SP Default passwordAbout SELF-ENCRYPTING Drives Locking SPData Bands Defect and Error Management SSD Physical format address descriptorDrive Error Recovery Procedures Identifying a Protection Information drive Setting and determining the current Type LevelLevels of PI Installation Physical interfaceX = F 15lb = 67N Interface Requirements Task management functionsSAS task management functions supported Task management responsesSupported commands Format UnitPersistent Reserve Reassign Blocks Write and Verify Inquiry data Pulsar.2 Inquiry dataMode Sense data Mode Pages Mode Sense data for 800GB drivesMode Sense data for 400GB drives Mode Sense data for 200GB drives Mode Sense values for 100GB drives SAS physical interface Miscellaneous featuresMiscellaneous status Datum B Section C C Section a a Physical characteristics Connector requirementsElectrical description Pin descriptionsPower LED drive signalSAS transmitters and receivers Ready LED Out5G B/ S 0G B/ S Differential signalsGeneral interface characteristics Index Index SAS See also cooling Seagate Technology LLC Americas

ST800FM0002, ST100FM0002, ST200FM0002, ST400FM0012, ST800FM0032 specifications

The Seagate ST100FM0012, ST800FM0012, ST400FM0042, ST400FM0002, and ST100FM0052 are high-performance hard drives designed for enterprise applications, offering advanced features and reliability for demanding workloads.

The ST100FM0012 is a 10TB hard drive that strikes a balance between capacity and performance. It utilizes a 7200 RPM spindle speed and features a 256MB cache, enabling efficient data access and enhanced read/write performance. With Seagate’s AgileArray technology, the ST100FM0012 is optimized for NAS environments, providing multi-drive reliability and error recovery.

The ST800FM0012 is an 8TB variant that shares many features with its 10TB counterpart but is tailored for organizations needing robust storage without reaching the highest tier of capacity. Its dual-plane rotational vibration technology minimizes vibration in multi-drive systems, ensuring sustained performance over prolonged use. This makes it an excellent choice for virtualization and data-intensive applications.

The ST400FM0042 offers a 4TB capacity suited for smaller enterprise needs or as a backup solution. With an impressive performance profile, including a 7200 RPM speed and 128MB cache, it accommodates both sequential and random workloads with ease. This drive stands out with its PowerChoice technology, allowing users to manage power consumption and reduce operational costs.

Another 4TB option, the ST400FM0002, is particularly designed for hybrid configurations, pairing the fast access of the hard drive with the speed of SSDs. It features Seagate's advanced thermal management technologies, ensuring optimal operating temperatures and performance stability during intensive workloads.

The ST100FM0052 rounds out the lineup with a 10TB capacity but is specifically aimed at surveillance applications. It supports a workload rate of 180TB per year, making it ideal for always-on recording scenarios. The drive is built with optimized firmware, which ensures enhanced performance in write-intensive environments, essential for video recording and security systems.

All these drives are equipped with Seagate’s proprietary technologies, including data recovery services and built-in data protection features, ensuring data integrity and security. The drives are built for durability, reliability, and high performance in mission-critical environments, making them indispensable components of modern enterprise data storage solutions. With capacities ranging from 4TB to 10TB, they cater to varying storage needs across different sectors.
Top Page Image Contents