Seagate, Seagate Technology and the Wave logo are registered trademarks of Seagate Technology LLC
in the United States and/or other countries. Savvio, 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.
One gigabyte, or GB, equals one billion bytes when referring to hard drive capacity. Accessible capacity
may vary depending on operating environment and formatting. 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.
Savvio 15K SAS Product Manual, Rev. B
i
Revision status summary sheet
RevisionDateNotes
Rev. A09/15/06Initial release.
Rev. B03/28/07Changes per ECR0076456.
This manual describes Seagate Technology® LLC, Savvio® 15K SAS (Serial Attached SCSI) disc drives.
Savvio drives support the SAS Pro tocol to th e extent described in this manual. The SAS Interface M anual (part
number 100293071) and SCSI Commands Reference Manual (part number 100293068) describe the general
SAS characteristics of these and other Seagate SAS drives.
2
Savvio 15K SAS Product Manual, Rev. B
Savvio 15K SAS Product Manual, Rev. B
3
2.0Applicable standards and reference documentation
The drive has been d evelope d as a system p eriphe ral to the hig hest st and ards of desig n and constru c tion. 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 Savvio family complies with Seagate standards as noted in the appropr iate sections of this manual and the
Seagate SAS Interface Manual, part number 100293071.
The Savvio disc drive is a UL recognized component per UL1950, CSA certified to CAN/CSA C22.2 No. 95095, and VDE certified to VDE 0805 and EN60950.
2.1.1Electromagnetic compatibility
The drive, as delivered, is designed for system integration and installation into a suitable enclosure pri or 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 i n 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.
2.1.1.1E lect roma gn etic susc ept ibility
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 Tables 2 and 3, DC power requirements.
4
Savvio 15K SAS Product Manual, Rev. B
2.1.2Electromagn etic complia nce
Seagate uses an independent laboratory to confirm compliance with the directives/standards for CE Marking
and C-Tick Marking. T he dr ive was tested in a r epre sent ative system for typica l applications. The select ed system represents the most popular characteristics for test platforms. The system configurations include:
• Typical current use microprocessor
• 3.5-inch floppy disc drive
• Keyboard
• Monitor/display
•Printer
• External modem
•Mouse
Although the test system with th is Seag ate mo del comp lies with the dir ectives/st and ards, we cannot gu aran tee
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 Min ist ry of Infor mat ion and Com munication (MIC) logo, it complies with paragr aph
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).
Savvio 15K SAS Product Manual, Rev. B
5
2.1.3European Union Restriction of Hazardous Substances (RoHS)
The European U nion Restr icti on of Hazard ous S ubst ance s (RoHS ) Dire cti ve re strict s the p resen ce of ch emic al
substances, including Lead (Pb), in electronic products effective July 2006.
A number of parts and materials in Seagate products are procured from external suppliers. We rely on the representations of our suppliers regarding the presence of RoHS substances in these parts and materials. Our
supplier contracts require compliance with our chemical substance restrictions, and our suppliers document
their compliance wi th our re quire ment s by providing material content declarations for all par ts an d mater i als for
the disc drives documented in this publication. Current supplier declarations include disclosure of the inclusion
of any RoHS-regulated substance in such parts or materials.
Seagate also has internal system s in place to en sure ongoing complian ce with the RoHS Directive and all laws
and regulations which restrict chemical conte nt in electron ic produ cts. T hese system s include sta ndar d operating procedures that ensure that restricted substances are not utilized in our manufacturing operations, laboratory analytical validation testing, and an internal auditing process to ensure that all standard operating
procedures are complied with.
2.2Reference documents
Savvio 15K SAS Installation GuideSeagate part number: 100407741
SCSI Commands Reference ManualSeagate part number: 100293068
SAS Interface ManualSeagate part number: 100293071
ANSI SAS Documents
SFF-82232.5” 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 Architecure Model-3 (SAM-3) Standard (T10/1561-D)
ISO/IEC 14776-xxxSCSI Primary Commands-3 Standard (T10/1416-D)
ISO/IEC 14776-xxxSCSI Block Commands-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 Procedures
Seagate 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.
6
Savvio 15K SAS Product Manual, Rev. B
Savvio 15K SAS Product Manual, Rev. B
7
3.0General description
Savvio drives combine giant magnetoresistive (GMR) heads, partial response/maximum likelihood (PRML)
read channel electronics, embedded servo technology, 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 nextgeneration computing demands for performance, scalability, flexibility and high-density storage requirements.
Savvio 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. Savvio 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 syste ms with eithe r S AS or SATA hard disc drives. This allows you to co ntinue to levera ge yo ur
existing investment in SCSI while gaining a 3Gb/s serial data transfer rate.
The head and disc 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.
Savvio drives use a dedicated landing zone at the innermost radius of the media to eliminate the possibility of
destroying or de grad i ng d at a b y l and ing in the data zone. The heads autom atic ally go t o th e lan di ng zone when
power is removed from the drive.
An automatic shipping lock prevents potential damage to the heads and discs 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.
Savvio drives decode track 0 location data from the servo data embedded on each surface to eliminate
mechanical transducer adjustments and related reliability concerns.
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.
8
Savvio 15K SAS Product Manual, Rev. B
3.1Standard featu re s
Savvio drives have the following standard features:
• Perpendicular recording technology
• 1.5 / 3Gbit Serial Attached SCSI (SAS) interface
• Integrated dual port SAS controller supporting the SCSI protocol
• Support for SAS expanders and fanout adapters
• Firmware downloadable 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)
• Industry standard SFF 2.5-inch dimensions
• 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 320 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)
• Idle Read After Write (IRAW)
• Power Save
3.2Media desc ription
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
• 15k RPM spindle. Average latency = 2.0 msec
• Background processing of queue
• Supports start and stop commands (spindle stops spinning)
• Mean Time Between Failures (MTBF) of 1,600,000 hours
• Incorporates industry-standard Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.)
• 5-year warranty
3.5Formatted ca pacities
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 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 compatibili ty from generation to generation. The current guaranteed operating points for this product are:
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 cap acity to the value in the Nu mber of Blocks field. A value gre ater t han th e maxim um nu mbe r of
LBAs is rounded down to the maximum capacity.
3.7Factory-installed accessories
OEM standard drives are shipped with the Savvio 15K SAS Installation Guide (part number 100407741)
unless otherwise specified.
10
Savvio 15K SAS Product Manual, Rev. B
3.8Options
You may order the followin g 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 Savvio 15K SAS Installation Guide, part number 100407741, is usually included with each standard
OEM drive shipped, but extra copies may be ordered.
• The Safety and Regulatory Agency Specifications, part number 75789512, is usually included with each
standard OEM drive shipped, but extra copies may be ordered.
Savvio 15K SAS Product Manual, Rev. B
11
4.0Performance characteristics
This section provides de ta iled inform ation concerning performance-related chara cteri stics an d featur es of S avvio drives.
4.1Internal drive characteristics
ST973451SSST936751SS
Drive capacity73.436.7Gbytes (formatted, rounded off value)
Read/write data heads42
Tracks per surface (total)42,55442,554Tracks (user accessible including spare tracks)
Tracks per inch150150kTPI (average)
Peak bits per inch861.81861.81kBPI
Areal density130.58130.58Gbit/in
Internal data rate957.51 to 1,282.08957.51 to 1,282.08Mbits/sec (variable with zone)
Disc rotation speed15k15krpm
Avg rotational latency22msec
4.2Seek performance characteristics
See Section 9.4.1, "SAS physical interface" on page 54 and the SAS Interface Manual (part number
100293071) for additional timing details.
2
4.2.1Access time (Gen 2.0 LP data)
Not including controller overhead (msec)
ReadWrite
AverageTypical
Single trackTypical
Full stro keTypical
1.Typical access times are measured under nominal conditions of temperature, voltage, and horiz ontal orientation as
measured on a representative sample of drives.
2.Access to data = access time + latency time.
1,2
1,2
1,2
2.93.3
0.20.4
5.15.5
12
Savvio 15K SAS Product Manual, Rev. B
4.2.2Format command execution time
ST973451SSST936751SS
Maximum (wi th verify)
Maximum (without verify)
52 minutes26 minutes
35 minutes18 minutes
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
Sustained trasfer rate79 to 112 Mbytes/sec
SAS Interface maximum instantaneous transfer rate300 Mbytes/sec* per port
(dual port = 600 Mbytes/sec*)
Logical block sizes
512 (default), 520, 524 and 528
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.)
Average rotational lat ency2.0 msec
*Assumes no errors and no relocated logical blocks. Rate measured from the start of the first logical block transfer to or
from the host.
Negligible
Savvio 15K SAS Product Manual, Rev. B
13
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 ) pri mitive, the drive waits for a START STO P UNIT com mand with the START bit e qual 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 S PINUP) 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 comm and m ay be used to comm and the dr iv e to st op the spindle. Stop time is 30 seconds (maximum) from removal of DC power. There is no power control switch on the drive.
4.4Prefetch /m ulti-segmented cache co ntrol
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 Table 9.
4.5Cache operation
Note.Refer to the SAS Interface Manual for more detail concerning the cache bits.
Of the 16 Mbytes physical buffer sp ace i n the drive, approxim atel y 13,0 00 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 In terfa ce Manu al ), data requested by t he host with a rea d comm and
is retrieved from the buf fe r, if possible, before any disc acce ss is initiated . If cach e oper ati on is not en abled, the
buffer is still used, but only as circular buffer segments during disc 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 i t. 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 recei ved 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:
14
Savvio 15K SAS Product Manual, Rev. B
1. The drive fetches the requested logical blocks from the disc 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.
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 dat a logical blo cks excee d the size o f the segm ent b eing wr itten into, wh en th e en d of the
segment is reached, the data is written into the b egi nnin g of the sa me cache segme nt, 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 i nto 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 Ca che command may be used to force the drive to write all cached write data to the med i um.
Upon completion of a Synchronize Cache command, all data received from previous write commands will have
been written to the medium.
Table 9 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 disc immedi ately 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 disc 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.
Savvio 15K SAS Product Manual, Rev. B
15
5.0Reliability specificatio ns
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 108 seeks
Read Error Rates
Recovered DataLess than 10 errors in 1012 bits transferred (OEM default settings)
Unrecovered DataLess than 1 sector in 1016 bits transferred
Miscorrected DataLess than 1 sector in 1021 bits transferred
Interface error rate:Less than 1 error in 1012 bits transferred
Mean Time Between Failure (MTBF): 1,600,000 hours
Annualized Failure Rate (AFR)0.55%
Preventive maintenance:None required
1.Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.
5.1Error rate s
The error rates stated in this manual assume the following:
• The drive is operated in accordance with this manual using DC power as defined in paragraph 6.2, "DC
power requirements."
• 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
Recovereable errors are those detected and corrected by the drive, and do not require user intervention.
Recoverable Data errors will use correction, although ECC o n-the-fly is not considered fo r purposes o f recov-
ered 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
An unrecoverable data error is defined as a failure of the drive to recover data from the media. These errors
occur due to head/media or write problems. Unrecoverable data errors are only detected during read operations, but not caused by the read. If an unrecoverable data error is detected, a MEDIUM ERROR (03h) in the
Sense Key will be reported. Multiple unrecoverable data errors resulting from the same cause are treated as 1
error.
16
Savvio 15K SAS Product Manual, Rev. B
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 recover y process. If the er ror recover y process fail s,
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 Savvio disc drives by en suring that th e drive receive s adequ ate coo l ing. 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 Failure (MTBF)
The production disc drive shall achieve an AFR of 0.55% (MTBF of 1,600,000 hours) when operated in an
environment that en sure s the H DA case temp erat ures do no t exceed the values specified in Section 6.4. Operation at case temperatures outside the specifications in Section 6.4 may increase the product AFR (decrease
the MTBF). The AFR (MTBF) is a population statistic not releveant to individual units.
The AFR (MTBF) specification is based on the following assumptions for Business Critical Storage System
environments:
• 8,760 power-on hours per year.
• 250 average on/off cycles per year.
• Operations at nominal voltages.
• Systems will provide adequate cooling to ensure the case temperatures specified in Section 6.4 are not
exceeded. Temperatures outside the specifications in Section 6.4 will increase the product AFR and
decrease the MTBF.
5.2.2Preventive mainte nan ce
No routine scheduled preventive maintenance is required.
5.2.3Hot plugging the drive
When a disc 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 betw een 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 drive 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 m ust come to a com pl ete s top pr ior to ch angi ng the pla ne of o pera ti on. T his time i s
Savvio 15K SAS Product Manual, Rev. B
17
required to insure data integrity.
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 f irmwar e moni tor s specific attr ibutes for degr adatio n ove r tim e b ut can ’ t predi ct in sta nt a-
neous 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 optimiz ed to minimize “false” and “failed” predicti ons.
Controlling S.M.A.R.T.
The operating mode of S.M.A.R. T. is controlled by the DEXCPT and PERF bit s 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 enab led, 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 dri ve thro ugh th e host t o dete rmi ne the tim e rem ai ning b efore the ne xt schedu l ed me asurement and d at a logg i ng p rocess occur s . To accomplish this, issue a Log Sense comm and to l o g p age 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 disc 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 disc 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 error s occur and signa ls a predictive fai lure if the rat e of degrad ed err ors
increases to an unacceptabl e level. To determi ne 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.
18
Savvio 15K SAS Product Manual, Rev. B
Error rate is the number of errors per oper ation. The algori thm tha t S .M.A.R .T. uses to record rates of err or 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.
5.2.5Thermal monitor
Savvio 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 dat a. You can use this information to determine if the warni ng is due to the temperature exceeding
the drive threatening temperature or the user-specified temperature.
This feature is controlled by the En able W a rni ng (EWasc) bit, and the reporting mechanism is cont rolled 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 65°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 re feren ce tempe ratur e p aram eter in the tempera ture log page (see Table 1) can
be used to set this trip point. The default value for this drive is 65°C, however, you can set it to any value in the
range of 0 to 65°C. If you specify a temperature greater than 65°C in this field, the temperature is rounded
down to 65°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
5.2.6Drive 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
Loading...
+ 60 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.