Seagate, Seagate Technology and the Wave logo are registered trademarks of Seagate Technology LLC
in the United States and/or other countries. Barracuda ES.2, SeaTools and SeaTDD are either trademarks
or registered trademarks of Seagate Technology LLC or one of its affiliated companies in the United States
and/or other countries. All other trademarks or registered trademarks are the property of their respective
owners.
When referring to hard drive capacity, one gigabyte, or GB, equals one billion bytes and one terabyte, or
TB, equals one trillion bytes. Your computer's operating system may use a different standard of measurement and report a lower capacity. In addition, some of the listed capacity is used for formatting and other
functions, and thus will not be available for data storage. Quantitative usage examples for various applications are for illustrative purposes. Actual quantities will vary based on various factors, including file size,
file format, features and application software. Seagate reserves the right to change, without notice, product
offerings or specifications.
For information regarding data recovery services, visit http://www.i365.com
For Seagate OEM and Distribution partner portal, visit https://direct.seagate.com/portal/system
For Seagate reseller portal, visit http://spp.seagate.com
Barracuda ES.2 SAS Product Manual, Rev. F iii
iv Barracuda ES.2 SAS Product Manual, Rev. F
1.0Scope
This manual describes Seagate Technology® LLC, Barracuda® ES.2 SAS (Serial Attached SCSI) disk drives.
Barracuda ES.2 drives support the SAS Protocol specifications to the extent described in this manual. The
SAS Interface Manual (part number 100293071) describes the general SAS characteristics of Barracuda ES.2
and other Seagate SAS drives.
Barracuda ES.2 SAS Product Manual, Rev. F1
2Barracuda ES.2 SAS Product Manual, Rev. F
2.0Standards, compliance and reference documents
The drive has been developed as a system peripheral to the highest standards of design and construction. The
drive depends on its host equipment to provide adequate power and environment for optimum performance
and compliance with applicable industry and governmental regulations. Special attention must be given in the
areas of safety, power distribution, shielding, audible noise control, and temperature regulation. In particular,
the drive must be securely mounted to guarantee the specified performance characteristics. Mounting by bottom holes must meet the requirements of Section 8.3.
2.1Standards
The Barracuda ES.2 SAS family complies with Seagate standards as noted in the appropriate sections of this
manual and the Seagate SAS Interface Manual, part number 100293071.
The Barracuda ES.2 disk drive is a UL recognized component per UL1950, CSA certified to CAN/CSA C22.2
No. 950-95, and VDE or TUV certified to EN60950.
2.1.1Electromagnetic compatibility
The drive, as delivered, is designed for system integration and installation into a suitable enclosure prior to
use. The drive is supplied as a subassembly and is not subject to Subpart B of Part 15 of the FCC Rules and
Regulations nor the Radio Interference Regulations of the Canadian Department of Communications.
The design characteristics of the drive serve to minimize radiation when installed in an enclosure that provides
reasonable shielding. The drive is capable of meeting the Class B limits of the FCC Rules and Regulations of
the Canadian Department of Communications when properly packaged; however, it is the user’s responsibility
to assure that the drive meets the appropriate EMI requirements in their system. Shielded I/O cables may be
required if the enclosure does not provide adequate shielding. If the I/O cables are external to the enclosure,
shielded cables should be used, with the shields grounded to the enclosure and to the host controller.
2.1.1.1Electromagnetic susceptibility
As a component assembly, the drive is not required to meet any susceptibility performance requirements. It is
the responsibility of those integrating the drive within their systems to perform those tests required and design
their system to ensure that equipment operating in the same system as the drive or external to the system
does not adversely affect the performance of the drive. See Table 2 for DC power requirements.
Barracuda ES.2 SAS Product Manual, Rev. F3
2.2Compliance
2.2.1Electromagnetic compliance
Seagate uses an independent laboratory to confirm compliance with the directives/standards for CE Marking
and C-Tick Marking. The drive was tested in a representative system for typical applications. The selected system represents the most popular characteristics for test platforms. The system configurations include:
• Typical current use microprocessor
• Keyboard
• Monitor/display
• Printer
• External modem
• Mouse
Although the test system with this Seagate model complies with the directives/standards, we cannot guarantee
that all systems will comply. The computer manufacturer or system integrator shall confirm EMC compliance
and provide the appropriate marking for their product.
Electromagnetic compliance for the European Union
If this model has the CE Marking it complies with the European Union requirements of the Electromagnetic
Compatibility Directive 89/336/EEC of 03 May 1989 as amended by Directive 92/31/EEC of 28 April 1992 and
Directive 93/68/EEC of 22 July 1993.
Australian C-Tick
If this model has the C-Tick Marking it complies with the Australia/New Zealand Standard AS/NZS3548 1995
and meets the Electromagnetic Compatibility (EMC) Framework requirements of Australia’s Spectrum Management Agency (SMA).
Korean MIC
If this model has the Korean Ministry of Information and Communication (MIC) logo, it complies with paragraph
1 of Article 11 of the Electromagnetic Compatibility (EMC) Control Regulation and meets the Electromagnetic
Compatibility Framework requirements of the Radio Research Laboratory (RRL) Ministry of Information and
Communication Republic of Korea.
Taiwanese BSMI
If this model has two Chinese words meaning “EMC certification” followed by an eight digit identification number, as a Marking, it complies with Chinese National Standard (CNS) 13438 and meets the Electromagnetic
Compatibility (EMC) Framework requirements of the Taiwanese Bureau of Standards, Metrology, and Inspection (BSMI).
4Barracuda ES.2 SAS Product Manual, Rev. F
2.3Reference documents
SCSI Commands Reference ManualSeagate part number: 100293068
SAS Interface ManualSeagate part number: 100293071
Applicable ANSI SAS documents
SFF-83233.5” Drive Form Factor with Serial Connector
SFF-8460HSS Backplane Design Guidelines
SFF-8470Multi Lane Copper Connector
SFF-8482SAS Plug Connector
ANSI INCITS.xxx Serial Attached SCSI (SAS) Standard (T10/1562-D)
ISO/IEC 14776-xxxSCSI Architecture Model-3 (SAM-3) Standard (T10/1561-D)
ISO/IEC 14776-xxxSCSI Primary Commands-3 (SPC-3) Standard (T10/1416-D)
ISO/IEC 14776-xxxSCSI Block Commands-2 (SBC-2) Standard (T10/1417-D)
ANSI Small Computer System Interface (SCSI) Documents X3.270-1996(SCSI-3) Architecture Model
Specification for Acoustic Test Requirement and ProceduresSeagate part number: 30553-001
Package Test SpecificationSeagate P/N 30190-001 (under 100 lb.)
Package Test SpecificationSeagate P/N 30191-001 (over 100 lb.)
In case of conflict between this document and any referenced document, this document takes precedence.
Barracuda ES.2 SAS Product Manual, Rev. F5
6Barracuda ES.2 SAS Product Manual, Rev. F
3.0General description
Barracuda ES.2 drives combine Tunneling Magnetoresistive (TMR) heads and a Serial Attached SCSI (SAS)
interface to provide high performance, high capacity data storage for a variety of systems including engineering workstations, network servers, mainframes, and supercomputers. The Serial Attached SCSI interface is
designed to meet next-generation computing demands for performance, scalability, flexibility and high-density
storage requirements.
Barracuda ES.2 drives are random access storage devices designed to support the Serial Attached SCSI Protocol as described in the ANSI specifications, this document, and the SAS Interface Manual (part number
100293071) which describes the general interface characteristics of this drive. Barracuda ES.2 drives are classified as intelligent peripherals and provide level 2 conformance (highest level) with the ANSI SCSI-1 standard.
The SAS connectors, cables and electrical interface are compatible with Serial ATA (SATA), giving future users
the choice of populating their systems with either SAS or SATA hard disk drives. This allows you to continue to
leverage your existing investment in SCSI while gaining a 3Gb/s serial data transfer rate.
The head and disk assembly (HDA) is sealed at the factory. Air recirculates within the HDA through a nonreplaceable filter to maintain a contamination-free HDA environment.
Note.Never disassemble the HDA and do not attempt to service items in the sealed enclosure (heads,
media, actuator, etc.) as this requires special facilities. The drive does not contain user-replaceable
parts. Opening the HDA for any reason voids your warranty.
An automatic shipping lock prevents potential damage to the heads and disks that results from movement during shipping and handling. The shipping lock disengages and the head load process begins when power is
applied to the drive.
The drives also use a high-performance actuator assembly with a low-inertia, balanced, patented, straight arm
design that provides excellent performance with minimal power dissipation.
Figure 1. Barracuda ES.2 drive illustration
Barracuda ES.2 SAS Product Manual, Rev. F7
3.1Standard features
Barracuda ES.2 SAS drives have the following standard features:
• Perpendicular recording technology
• 1.5 / 3Gbit Serial Attached SCSI (SAS) interface
• Integrated dual port SAS controller
• Support for SAS expanders and fanout adapters
• Downloadable firmware using the SAS interface
• 128 - deep task set (queue)
• Supports up to 32 initiators
• Jumperless configuration.
• User-selectable logical block size (512, 520, 524, or 528 bytes per logical block)
• Programmable logical block reallocation scheme
• Flawed logical block reallocation at format time
• Programmable auto write and read reallocation
• Reallocation of defects on command (Post Format)
• ECC maximum burst correction length of 400 bits
• No preventive maintenance or adjustments required
• Dedicated head landing zone
• Embedded servo design
• Automatic shipping lock
• Self diagnostics performed when power is applied to the drive
• Zone bit recording (ZBR)
• Vertical, horizontal, or top down mounting
• Dynamic spindle brake
• 16 Mbyte data buffer (see Section 4.5).
• Drive Self Test (DST)
• Background Media Scan (BGMS)
• Power Save
3.2Media description
The media used on the drive has an aluminum substrate coated with a thin film magnetic material, overcoated
with a proprietary protective layer for improved durability and environmental protection.
3.3Performance
• Firmware-controlled multisegmented cache designed to dynamically adjust segments for enhanced system
performance.
• 300 Mbytes/sec maximum instantaneous data transfers.
• 7,200 RPM spindle. Average latency = 4.16 msec
• Command queuing of up to 128 commands
• Background processing of queue
• Supports start and stop commands (spindle stops spinning)
• Mean Time Between Failures (MTBF) of 1,200,000 hours
• Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.)
• 5-year warranty
8Barracuda ES.2 SAS Product Manual, Rev. F
3.5Formatted capacities
Standard OEM models are formatted to 512 bytes per block. The block size is selectable at format time and
must be a multiple of 4 bytes. Users having the necessary equipment may modify the data block size before
issuing a format command and obtain different formatted capacities than those listed.
To provide a stable target capacity environment and at the same time provide users with flexibility if they
choose, Seagate recommends product planning in one of two modes:
1. Seagate designs specify capacity points at certain block sizes that Seagate guarantees current and future
products will meet. We recommend customers use this capacity in their project planning, as it ensures a
stable operating point with backward and forward compatibility from generation to generation. The current
guaranteed operating points for this product are:
ST31000640SSST3750630SSST3500620SS
Sector Size
DecimalDecimalDecimal
5121,953,525,1681,465,149,168976,773,168
5201,923,076,9301,442,307,698961,538,465
5241,882,972,5621,412,229,422941,486,281
5281,876,331,3301,407,248,498938,165,665
2. Seagate drives also may be used at the maximum available capacity at a given block size, but the excess
capacity above the guaranteed level will vary between other drive families and from generation to generation, depending on how each block size actually formats out for zone frequencies and splits over servo
bursts. This added capacity potential may range from 0.1 to 1.3 percent above the guaranteed capacities
listed above. Using the drives in this manner gives the absolute maximum capacity potential, but the user
must determine if the extra capacity potential is useful, or whether their assurance of backward and forward compatibility takes precedence.
3.6Programmable drive capacity
Using the Mode Select command, the drive can change its capacity to something less than maximum. See the
Mode Select (6) parameter list table in the SAS Interface Manual, part number 100293071. A value of zero in
the Number of Blocks field indicates that the drive will not change the capacity it is currently formatted to have.
A number other than zero and less than the maximum number of LBAs in the Number of Blocks field changes
the total drive capacity to the value in the Number of Blocks field. A value greater than the maximum number of
LBAs is rounded down to the maximum capacity.
3.7Factory-installed options
You may order the following items which are incorporated at the manufacturing facility during production or
packaged before shipping. Some of the options available are (not an exhaustive list of possible options):
• Other capacities can be ordered depending on sparing scheme and sector size requested.
• Single-unit shipping pack. The drive is normally shipped in bulk packaging to provide maximum protection
against transit damage. Units shipped individually require additional protection as provided by the single unit
shipping pack. Users planning single unit distribution should specify this option.
• The Safety and Regulatory Agency Specifications, part number 75789512, is usually included with each
standard OEM drive shipped, but extra copies may be ordered.
Barracuda ES.2 SAS Product Manual, Rev. F9
10Barracuda ES.2 SAS Product Manual, Rev. F
4.0Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of
Barracuda ES.2 SAS drives.
Internal data rate1,2871,2871,287Mb/s max (variable with zone)
Sustained data rate116116116MB/s max (variable with zone)*
Disk rotation speed7,2007,2007,200RPM
Avg rotational latency4.164.164.16msec
*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment
and formatting.
4.2Seek performance
2
*
See Section 9.4.1, "SAS physical interface" on page 55 and the SAS Interface Manual (part number
100293071) for additional timing details.
4.2.1Access time
1
Not Including controller overhead2 (msec)
ReadWrite
AverageTypical7.48.5
Single trackTypical0.41.0
Full strokeTypical14.315.4
1.Typical access times are measured under nominal conditions of temperature, voltage, and
horizontal orientation as measured on a representative sample of drives.
2.Access to data = access time + latency time.
,
Barracuda ES.2 SAS Product Manual, Rev. F11
4.2.2Format command execution time (minutes)
ST31000640SSST3750630SSST3500620SS
Maximum (with verify)400300200
Maximum (without verify)200150100
Execution time measured from receipt of the last byte of the Command Descriptor Block (CDB) to the request
for a Status Byte Transfer to the Initiator (excluding connect/disconnect).
4.2.3General performance characteristics
Sustainable disk transfer rate*:
Minimum56 Mbytes/sec
Maximum116 Mbytes/sec
SAS Interface maximum instantaneous transfer rate300 Mbytes/sec* per port
Logical block sizes
Default is 512-byte data blocks
Sector sizes variable to 512, 520, 524, and 528 kbytes.
Read/write consecutive sectors on a trackYes
Flaw reallocation performance impact (for flaws reallocated at format time using
the spare sectors per sparing zone reallocation scheme.)
*Assumes no errors and no relocated logical blocks. Rate measured from the start of the first logical block transfer to or from the host.
(dual port = 600 Mbytes/sec*)
Negligible
4.3Start/stop time
The drive accepts the commands listed in the SAS Interface Manual less than 3 seconds after DC power has
been applied.
If the drive receives a NOTIFY (ENABLE SPINUP) primitive through either port and has not received a START
STOP UNIT command with the START bit equal to 0, the drive becomes ready for normal operations within 20
seconds (excluding the error recovery procedure).
If the drive receives a START STOP UNIT command with the START bit equal to 0 before receiving a NOTIFY
(ENABLE SPINUP) primitive, the drive waits for a START STOP UNIT command with the START bit equal to
1. After receiving a START STOP UNIT command with the START bit equal to 1, the drive waits for a NOTIFY
(ENABLE SPINUP) primitive. After receiving a NOTIFY (ENABLE SPINUP) primitive through either port, the
drive becomes ready for normal operations within 20 seconds (excluding the error recovery procedure).
If the drive receives a START STOP UNIT command with the START bit and IMMED bit equal to 1 and does
not receive a NOTIFY (ENABLE SPINUP) primitive within 5 seconds, the drive fails the START STOP UNIT
command.
The START STOP UNIT command may be used to command the drive to stop the spindle. Stop time is 20 seconds (maximum) from removal of DC power.
There is no power control switch on the drive.
12Barracuda ES.2 SAS Product Manual, Rev. F
4.4Prefetch/multi-segmented cache control
The drive provides a prefetch (read look-ahead) and multi-segmented cache control algorithms that in many
cases can enhance system performance. Cache refers to the drive buffer storage space when it is used in
cache operations. To select this feature, the host sends the Mode Select command with the proper values in
the applicable bytes in page 08h. Prefetch and cache operations are independent features from the standpoint
that each is enabled and disabled independently using the Mode Select command; however, in actual operation, the prefetch feature overlaps cache operation somewhat as described in sections 4.5.1 and 4.5.2.
All default cache and prefetch mode parameter values (Mode Page 08h) for standard OEM versions of this
drive family are given in Section 9.3.2.1.
4.5Cache operation
Note.Refer to the SAS Interface Manual for more detail concerning the cache bits.
Of the 16 Mbytes physical buffer space in the drive, approximately 13,000 kbytes can be used as a cache. The
buffer is divided into logical segments from which data is read and to which data is written.
The drive keeps track of the logical block addresses of the data stored in each segment of the buffer. If the
cache is enabled (see RCD bit in the SAS Interface Manual ), data requested by the host with a read command
is retrieved from the buffer, if possible, before any disk access is initiated. If cache operation is not enabled, the
buffer is still used, but only as circular buffer segments during disk medium read operations (disregarding
Prefetch operation for the moment). That is, the drive does not check in the buffer segments for the requested
read data, but goes directly to the medium to retrieve it. The retrieved data merely passes through some buffer
segment on the way to the host. All data transfers to the host are in accordance with buffer-full ratio rules. See
the explanation provided with the information about Mode Page 02h (disconnect/reconnect control) in the SAS Interface Manual.
The following is a simplified description of the prefetch/cache operation:
Case A—read command is received and all of the requested logical blocks are already in the cache:
1. Drive transfers the requested logical blocks to the initiator.
Case B—A Read command requests data, and at least one requested logical block is not in any segment of
the cache:
1. The drive fetches the requested logical blocks from the disk and transfers them into a segment, and then
from there to the host in accordance with the Mode Select Disconnect/Reconnect parameters, page 02h.
2. If the prefetch feature is enabled, refer to section 4.5.2 for operation from this point.
Each cache segment is actually a self-contained circular buffer whose length is an integer number of logical
blocks. The drive dynamically creates and removes segments based on the workload. The wrap-around capability of the individual segments greatly enhances the cache’s overall performance.
Note.The size of each segment is not reported by Mode Sense command page 08h, bytes 14 and 15.
The value 0XFFFF is always reported regardless of the actual size of the segment. Sending a size
specification using the Mode Select command (bytes 14 and 15) does not set up a new segment
size. If the STRICT bit in Mode page 00h (byte 2, bit 1) is set to one, the drive responds as it does
for any attempt to change an unchangeable parameter.
4.5.1Caching write data
Write caching is a write operation by the drive that makes use of a drive buffer storage area where the data to
be written to the medium is stored while the drive performs the Write command.
Barracuda ES.2 SAS Product Manual, Rev. F13
If read caching is enabled (RCD=0), then data written to the medium is retained in the cache to be made available for future read cache hits. The same buffer space and segmentation is used as set up for read functions.
The buffer segmentation scheme is set up or changed independently, having nothing to do with the state of
RCD. When a write command is issued, if RCD=0, the cache is first checked to see if any logical blocks that
are to be written are already stored in the cache from a previous read or write command. If there are, the
respective cache segments are cleared. The new data is cached for subsequent Read commands.
If the number of write data logical blocks exceed the size of the segment being written into, when the end of the
segment is reached, the data is written into the beginning of the same cache segment, overwriting the data that
was written there at the beginning of the operation; however, the drive does not overwrite data that has not yet
been written to the medium.
If write caching is enabled (WCE=1), then the drive may return Good status on a write command after the data
has been transferred into the cache, but before the data has been written to the medium. If an error occurs
while writing the data to the medium, and Good status has already been returned, a deferred error will be generated.
The Synchronize Cache command may be used to force the drive to write all cached write data to the medium.
Upon completion of a Synchronize Cache command, all data received from previous write commands will have
been written to the medium.
Table 9.3.2.1 shows the mode default settings for the drive.
4.5.2Prefetch operation
If the Prefetch feature is enabled, data in contiguous logical blocks on the disk immediately beyond that which
was requested by a Read command are retrieved and stored in the buffer for immediate transfer from the buffer to the host on subsequent Read commands that request those logical blocks (this is true even if cache
operation is disabled). Though the prefetch operation uses the buffer as a cache, finding the requested data in
the buffer is a prefetch hit, not a cache operation hit.
To enable Prefetch, use Mode Select page 08h, byte 12, bit 5 (Disable Read Ahead - DRA bit). DRA bit = 0
enables prefetch.
The drive does not use the Max Prefetch field (bytes 8 and 9) or the Prefetch Ceiling field (bytes 10 and 11).
When prefetch (read look-ahead) is enabled (enabled by DRA = 0), the drive enables prefetch of contiguous
blocks from the disk when it senses that a prefetch hit will likely occur. The drive disables prefetch when it
decides that a prefetch hit is not likely to occur.
14Barracuda ES.2 SAS Product Manual, Rev. F
5.0Reliability specifications
The following reliability specifications assume correct host and drive operational interface, including all interface timings, power supply voltages, environmental requirements and drive mounting constraints.
Seek error rate:Less than 10 errors in 108seeks
Read Error Rates
Recovered DataLess than 10 errors in 1012 bits transferred (OEM default settings)
Unrecovered DataLess than 1 sector in 1015 bits transferred
Miscorrected DataLess than 1 sector in 1021 bits transferred
Interface error rate:Less than 1 error in 1012 bits transferred
MTBF1,200,000 hours
Annualized Failure Rate (AFR)0.73%
Preventive maintenance:None required
1.Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.
5.1Error rates
The error rates stated in this manual assume the following:
• The drive is operated in accordance with the manual using DC power as defined in Section 6.2.
• Errors caused by host system failures are excluded from error rate computations.
• Assume random data.
• Default OEM error recovery settings are applied. This includes AWRE, ARRE, full read retries, full write
retries and full retry time.
1
5.1.1Recoverable Errors
Recoverable errors are those detected and corrected by the drive, and do not require user intervention.
Recoverable Data errors will use correction, although ECC on-the-fly is not considered for purposes of recovered error specifications.
Recovered Data error rate is determined using read bits transferred for recoverable errors occurring during a
read, and using write bits transferred for recoverable errors occurring during a write.
5.1.2Unrecoverable Errors
Unrecoverable Data Errors (Sense Key = 03h) are specified at less than 1 sector in error per 1015 bits transferred. Unrecoverable Data Errors resulting from the same cause are treated as 1 error for that block.
Barracuda ES.2 SAS Product Manual, Rev. F15
5.1.3Seek errors
A seek error is defined as a failure of the drive to position the heads to the addressed track. After detecting an
initial seek error, the drive automatically performs an error recovery process. If the error recovery process fails,
a seek positioning error (Error code = 15h or 02h) will be reported with a Hardware error (04h) in the Sense
Key. Recoverable seek errors are specified at Less than 10 errors in 108 seeks. Unrecoverable seek errors
(Sense Key = 04h) are classified as drive failures.
5.1.4Interface errors
An interface error is defined as a failure of the receiver on a port to recover the data as transmitted by the
device port connected to the receiver. The error may be detected as a running disparity error, illegal code, loss
of word sync, or CRC error.
5.2Reliability and service
You can enhance the reliability of disk drives by ensuring that the drive receives adequate cooling. Section 6.0
provides temperature measurements and other information that may be used to enhance the service life of the
drive. Section 8.2 provides recommended air-flow information.
5.2.1Annualized Failure Rate (AFR) and Mean Time Between Failures (MTBF)
These drives shall achieve an AFR of 0.73% (MTBF of 1,200,000 hours) when operated in an environment that
ensures the HDA case temperatures do not exceed the values specified in Section 6.4.1.
Operation at case temperatures outside the specifications in Section 6.4.1 may increase the AFR (decrease
the MTBF).
AFR and MTBF statistics are population statistics that are not relevant to individual units. AFR and MTBF
specifications are based on the following assumptions for Enterprise Storage System environments:
• 8,760 power-on hours per year
• 250 average on/off cycles per year
• Operating at nominal voltages
• System provides adequate cooling to ensure the case temperatures specified in Section 6.4.1 are not
exceeded.
5.2.2Preventive maintenance
No routine scheduled preventive maintenance is required.
5.2.3Hot plugging the drive
When a disk is powered on by switching the power or hot plugged, the drive runs a self test before attempting
to communicate on its’ interfaces. When the self test completes successfully, the drive initiates a Link Reset
starting with OOB. An attached device should respond to the link reset. If the link reset attempt fails, or any
time the drive looses sync, the drive initiated link reset. The drive will initiate link reset once per second but
alternates between port A and B. Therefore each port will attempt a link reset once per 2 seconds assuming
both ports are out of sync.
If the self-test fails, the does not respond to link reset on the failing port.
Note.It is the responsibility of the systems integrator to assure that no temperature, energy, voltage haz-
ard, or ESD potential hazard is presented during the hot connect/disconnect operation. Discharge
the static electricity from the drive carrier prior to inserting it into the system.
Caution.The drive motor must come to a complete stop prior to changing the plane of operation. This time is
required to insure data integrity.
16Barracuda ES.2 SAS Product Manual, Rev. F
5.2.4S.M.A.R.T.
S.M.A.R.T. is an acronym for Self-Monitoring Analysis and Reporting Technology. This technology is intended
to recognize conditions that indicate imminent drive failure and is designed to provide sufficient warning of a
failure to allow you to back up the data before an actual failure occurs.
Note.The drive’s firmware monitors specific attributes for degradation over time but can’t predict instan-
taneous drive failures.
Each monitored attribute has been selected to monitor a specific set of failure conditions in the operating performance of the drive and the thresholds are optimized to minimize “false” and “failed” predictions.
Controlling S.M.A.R.T.
The operating mode of S.M.A.R.T. is controlled by the DEXCPT and PERF bits on the Informational Exceptions Control mode page (1Ch). Use the DEXCPT bit to enable or disable the S.M.A.R.T. feature. Setting the
DEXCPT bit disables all S.M.A.R.T. functions. When enabled, S.M.A.R.T. collects on-line data as the drive performs normal read and write operations. When the PERF bit is set, the drive is considered to be in “On-line
Mode Only” and will not perform off-line functions.
You can measure off-line attributes and force the drive to save the data by using the Rezero Unit command.
Forcing S.M.A.R.T. resets the timer so that the next scheduled interrupt is in two hours.
You can interrogate the drive through the host to determine the time remaining before the next scheduled measurement and data logging process occurs. To accomplish this, issue a Log Sense command to log page
0x3E. This allows you to control when S.M.A.R.T. interruptions occur. Forcing S.M.A.R.T. with the RTZ command resets the timer.
Performance impact
S.M.A.R.T. attribute data is saved to the disk so that the events that caused a predictive failure can be recreated. The drive measures and saves parameters once every two hours subject to an idle period on the drive
interfaces. The process of measuring off-line attribute data and saving data to the disk is uninterruptable. The
maximum on-line only processing delay is summarized below:
Reporting is controlled by the MRIE bits in the Informational Exceptions Control mode page (1Ch). Subject to
the reporting method, the firmware will issue to the host an 01-5Dxx sense code. The error code is preserved
through bus resets and power cycles.
Determining rate
S.M.A.R.T. monitors the rate at which errors occur and signals a predictive failure if the rate of degraded errors
increases to an unacceptable level. To determine rate, error events are logged and compared to the number of
total operations for a given attribute. The interval defines the number of operations over which to measure the
rate. The counter that keeps track of the current number of operations is referred to as the Interval Counter.
S.M.A.R.T. measures error rates. All errors for each monitored attribute are recorded. A counter keeps track of
the number of errors for the current interval. This counter is referred to as the Failure Counter.
Barracuda ES.2 SAS Product Manual, Rev. F17
Error rate is the number of errors per operation. The algorithm that S.M.A.R.T. uses to record rates of error is to
set thresholds for the number of errors and their interval. If the number of errors exceeds the threshold before
the interval expires, the error rate is considered to be unacceptable. If the number of errors does not exceed
the threshold before the interval expires, the error rate is considered to be acceptable. In either case, the interval and failure counters are reset and the process starts over.
Predictive failures
S.M.A.R.T. signals predictive failures when the drive is performing unacceptably for a period of time. The firmware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accomplish this, a counter is incremented each time the error rate is unacceptable and decremented (not to exceed
zero) whenever the error rate is acceptable. If the counter continually increments such that it reaches the predictive threshold, a predictive failure is signaled. This counter is referred to as the Failure History Counter.
There is a separate Failure History Counter for each attribute.
5.2.6Thermal monitor
Barracuda ES.2 drives implement a temperature warning system which:
1. Signals the host if the temperature exceeds a value which would threaten the drive.
2. Signals the host if the temperature exceeds a user-specified value.
3. Saves a S.M.A.R.T. data frame on the drive which exceeds the threatening temperature value.
A temperature sensor monitors the drive temperature and issues a warning over the interface when the temperature exceeds a set threshold. The temperature is measured at power-up and then at ten-minute intervals
after power-up.
The thermal monitor system generates a warning code of 01-0B01 when the temperature exceeds the specified limit in compliance with the SCSI standard. The drive temperature is reported in the FRU code field of
mode sense data. You can use this information to determine if the warning is due to the temperature exceeding the drive threatening temperature or the user-specified temperature.
This feature is controlled by the Enable Warning (EWasc) bit, and the reporting mechanism is controlled by the
Method of Reporting Informational Exceptions field (MRIE) on the Informational Exceptions Control (IEC)
mode page (1Ch).
The current algorithm implements two temperature trip points. The first trip point is set at 68°C which is the
maximum temperature limit according to the drive specification. The second trip point is user-selectable using
the Log Select command. The reference temperature parameter in the temperature log page (see Table 1) can
be used to set this trip point. The default value for this drive is 68°C, however, you can set it to any value in the
range of 0 to 68°C. If you specify a temperature greater than 68°C in this field, the temperature is rounded
down to 68°C. A sense code is sent to the host to indicate the rounding of the parameter field.
Table 1: Temperature Log Page (0Dh)
Parameter CodeDescription
0000hPrimary Temperature
0001hReference Temperature
5.2.7Drive Self Test (DST)
Drive Self Test (DST) is a technology designed to recognize drive fault conditions that qualify the drive as a
failed unit. DST validates the functionality of the drive at a system level.
There are two test coverage options implemented in DST:
1. Extended test
2. Short text
18Barracuda ES.2 SAS Product Manual, Rev. F
Loading...
+ 54 hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.