Publication number: 100384776, Rev. J May 2010
Seagate, Seagate Technology and the Wave logo are registered trademarks of Seagate Technology
LLC in the United States and/or other countries. Cheetah, SeaTools and SeaTDD are either trade
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No part of this publication may be reproduced in any form without written permission of Seagate
Technology LLC. Call 877-PUB-TEK1(877-782-8651) to request permission.
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.
For information regarding products and services, visit http://www.seagate.com/www/en-us/about/contact_us/
Available services include:
Presales & Technical support
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For information regarding Warranty Support, visit
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For Seagate reseller portal, visit http://spp.seagate.com
This manual describes Seagate® Technology LLC, Cheetah® 15K.5 SCSI disc drives.
Cheetah 15K.5 SCSI drives support the sm all computer system interface (SCSI) as described in the ANSI
SCSI SPI-4 interface specifications to the extent described in this manual. T he SCSI Interface Manual (part
number 100293069) describes general SCSI interface characteristics of this and other families of Seagate
drives.
From this point on in this product manual the reference to Cheetah 15K.5 SCSI models is referred to as “the
drive” unless references to individual models are necessary.
2Cheetah 15K.5 SCSI Product Manual, Rev. J
3.0Applicable standards and reference documentation
The drive has been developed as a system peripheral to the highest standards of design and construction. The
drive depends upon its host equipment to provide adequate power and environment in order to achieve 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 in order to guarantee the specified performance characteristics. Mounting by bottom holes must meet the requirements of Section 9.4.
3.1Standards
The Cheetah 15K.5 SCSI family complies w ith Seagate s tandards as noted in the appro priate sections of this
Manual, the Seagate Parallel SCSI Interface Manual, part number 100293069, and the SCSI Commands Ref-erence Manual, part number 100293068.
The Cheetah 15K.5 SCSI disc drive is a UL recognized component per UL1950, CSA certified to CSA C22.2
No. 950-95, and VDE or TUV certified to EN60950.
3.1.1Electromagnetic compatibility
The drive, as delivered, is designed for system integration and installation into a suitable enclosure prior to
use. As such 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. As such, 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 enclos ure does not prov ide adequate shielding. If the I/O cables are external to
the enclosure, shielded cables should be used, with the shields gro unded to the enclosure and to the host controller.
3.1.2Electromagnetic 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 3, DC power requirements.
Cheetah 15K.5 SCSI Product Manual, Rev. J3
3.2Electromagnetic compliance
Seagate uses an independent laboratory to confirm compliance to the directives/standard(s) for CE Marking
and C-Tick Marking. The drive was teste d in a repr esen t ative system for typical applications. The selected 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 this Seagate model complies to the directives/standard(s), we cannot guarantee
that all systems will comply. The computer manufacturer or system integrator shall confirm EMC compliance
and provide CE Marking and C-Tick 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 p aragr 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.
This drive has been tested and complies with the Electromagnetic Interference/Electromagnetic Susceptibility
(EMI/EMS) for Class B products.
Taiwanese BSMI
If this model has the Chinese National Standard (CNS) 13438 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).
3.3European Union Restriction of Hazardous Substances (RoHS)
The European Union Restriction of Hazardous Substances (RoHS) Directive restricts the presence of chemical
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 ch emical substance restrictions, and our suppliers document
their compliance with our requirements by providing material conten t declarations for all p arts and materials 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.
4Cheetah 15K.5 SCSI Product Manual, Rev. J
Seagate also has internal systems in place to ensure on going compliance with the RoHS Directive and all laws
and regulations which restrict chemical content in electronic products. These systems include standard 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.
T10/1365DSPI-4 (SCSI Parallel Interface version 4)
SFF-8451Specification for SCA-2 Unshielded Connections
Package Test SpecificationSeagate P/N 30190-001 (under 100 lb.)
Package Test SpecificationSeagate P/N 30191-001 (over 100 lb.)
Specification, Acoustic Test Requirements, and Procedures Seagate P/N 30553-001
In case of conflict between this document and any referenced document, this document takes precedence.
Cheetah 15K.5 SCSI Product Manual, Rev. J5
4.0General description
Cheetah 15K.5 SCSI drives combine Tunneling Magnetoresistive (TMR) heads and a wide Ultra320 SCSI
interface to provide high performance, high capacity data storage for a variety of systems including engineering workstations, network servers, mainframes, and supercomputers.
Ultra320 SCSI uses negotiated transfer rates. These transfer rates will occur only if your host adapter supports
these data transfer rates and is compatible with the required hardware requirements of the I/O circuit type. This
drive also operates at SCSI-1 and SCSI-2 data transfer rates for backward compatibility with non-Ultra/Ultra2/
Ultra160/Ultra320 SCSI host adapters.
Table 1 lists the features that differentiate the Cheet ah 15K.5 SCSI models.
Table 1: Drive model number vs. differentiating features
Model number
ST3300655LW
ST3146855LW
ST373455LW
ST3300655LC
ST3146855LC
ST373455LC
Number of
active headsI/O circuit type [1]
8
4
Single-ended (SE) and low voltage
differential (LVD)
2
8
4
Single-ended (SE) and low voltage
differential (LVD)
2
Number of I/O
connector pins
68
80
[1] See Section 10.6 for details and definitions.
The drive records and recovers data on approximately 70 mm non-removable discs.
The drive supports the Small Computer System Interface (SCSI) as described in the ANSI SCSI interface
specifications to the extent descr ibed in this m anual (volume 1), which defin es the prod uct performan ce characteristics of the Cheetah 15K.5 SCSI family of drives, the Parallel SCSI Interface Manual, part number
100293069, and the SCSI Commands Reference Manual, part number 100293068, which describe the general interface characteristics of this and other families of Seagate SCSI drives.
The drive’s interface supports multiple initiators, disconnect/reconnect, self-configuring host software, and logical block addressing.
The head and disc assembly (HDA) is sealed at the factory. Air circulates within the HDA through a nonreplaceable filter to maintain a contamination-free HDA environment.
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 contains no replaceable parts. Opening the HDA voids
your warranty.
Cheetah 15K.5 SCSI drives use a dedicated la nd ing zone at the i nne rmo st rad ius of the media to elimin ate th e
possibility of destroying or degrading data by landing in the data zone. The drive automatically goes to the
landing zone when power is removed.
6Cheetah 15K.5 SCSI Product Manual, Rev. J
An automatic shipping lock prevents potential damage to the heads and discs that results from movement during shipping and handling. The shipping lock automatically disengages when power is applied to the drive and
the head load process begins.
A high-performance actuator assembly with a low-inertia, balanced, patented, straight-arm design provides
excellent performance with minimal power dissipation.
4.1Standard features
The Cheetah 15K.5 SCSI family has the following standard features:
• Perpendicular recording technology.
• Integrated Ultra320 SCSI interface.
• Multimode SCSI drivers and receivers—single-ended (SE) and low voltage differential (LVD)
• 16 bit I/O data bus
• Asynchronous and synchronous data transfer protocol
• Firmware downloadable via SCSI interface
• Selectable even byte sector sizes from 512 to 528 bytes/sector
• Programmable sector reallocation scheme
• Flawed sector reallocation at format time
• Programmable auto write and read reallocation
• Reallocation of defects on command (post format)
• ECC burst correction length of up to 400.
• Sealed head and disc assembly
• No preventative maintenance or adjustment required
• Dedicated head landing zone
• Embedded servo design
• Self diagnostics performed when power is applied to the drive
• Zoned bit recording (ZBR)
• Vertical, horizontal, or top down mounting
• Dynamic spindle brake
• 16,384 kbytes data buffer
• Hot plug compatibility (Section 10.6.4.2 lists proper host connector needed) for LC model drives
• Drive Self Test (DST)
• Supports SCSI bus fairness
4.2Media characteristics
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.
Cheetah 15K.5 SCSI Product Manual, Rev. J7
4.3Performance
• Supports industry standard Ultra320 SCSI interface
• Programmable multi-segmentable cache buffer (see Section 5.5)
• 15k RPM spindle. Average latency = 2.0 msec
• Command queuing of up to 64 commands
• Background processing of queue
• Supports start and stop commands (spindle stops spinning)
4.4Reliability
• Annualized Failure Rate (AFR) of 0.62%
• Increased LSI circuitry integration
• Incorporates industry-standard Self-Monitoring, Analysis and Reporting Technology (S.M.A.R.T.)
• 5-year warranty
4.5Formatted capacities
Sta ndard OEM mode ls are formatted to 512 bytes per b lock. The se ctor size is select able at fo rmat time. 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 sector 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:
2. Seagate drives also may be used at th e maximum ava ilable cap acity at a given sector size, but the excess
capacity above the guaranteed level will vary between 10K and 15K families and from generation to gener
ation, depending on how each sector 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 for
ward compatibility takes precedence.
-
-
8Cheetah 15K.5 SCSI Product Manual, Rev. J
4.5.1Programmable drive capacity
Using the Mode Select command, the drive can change its capacity to something less than maximum. See the
Mode Select Parameter List table in the SCSI Interface Manual. Refer to the Parameter list block descriptor
number of blocks field. A value of zero in the number of blocks field indicates that the drive shall not change the
capacity it is currently formatted to have. A number in the number of blocks field that is less than the maximum
number of LBAs changes the total drive capacity to the value in the block descriptor number of blocks field. A
value greater than the maximum number of LBAs is rounded down to the maximum capacity.
4.6Factory installed accessories
OEM St an dard d rives a re shippe d with the Chee tah 15K.5 Installation Guide, part number 100384777, and the
Safety and Regulatory Agency Specifications, part number 75789512 (unless otherwise spe cified). The facto ry
also ships with the drive a small bag of jumper plugs used for the J5 and J6 option select jumper headers (on
LW models only).
4.7Options (factory installed)
All customer requested options are incorporated during production or packaged at the manufacturing facility
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 maxim um protection
against transit damage. Units shipped individually require additional protection as p rovided by the sin gle unit
shipping pack. Users planning single unit distribution should specify this option.
•The Cheetah 15K.5 Installation Guide, part number 100384777, usually ships with each standard OEM
drive. Extra copies may be ordered.
•The Safety and Regulatory Agency Specifications, part number 75789512, usually ships with each standard
OEM drive. Extra copies may be ordered.
4.8Accessories
The following accessories are available. All accessories may be installed in the field.
• Single unit shipping pack.
Cheetah 15K.5 SCSI Product Manual, Rev. J9
5.0Performance characteristics
5.1Internal drive characteristics (transparent to user)
Internal data rate960 to 1607960 to 1607960 to 1607Mbits/sec (variable with zone)
Disc rotational speed15k15k15krpm
Average rotational latency2.02.02.0msec
* One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment
and formatting.
** Rounded off value.
5.2SCSI performance characteristics (visible to user)
The values given in Section 5.2.1 apply to all models of the Cheetah 15K.5 SCSI family unless otherwise specified. Refer to the Parallel SCSI Interface Manual for additional timing details.
10Cheetah 15K.5 SCSI Product Manual, Rev. J
5.2.1Seek time
Not including controller overhead (msec)
ReadWrite
1,2
AverageTypical3.54.0
Single TrackTypical0.20.4
Full StrokeTypical6.87.5
1.Typical access times are measured under nominal conditions of temperature, volt-
age, and horizontal orientation as measured on a representative sample of drives.
2.Access to data = access time + latency time.
5.2.2Format command execution time (minutes ) [1]
ST3300655LW
ST3300655LC
ST3146855LW
ST3146855LC
ST373455LW
ST373455LC
Maximum (with verify)1209060
Maximum (no verify)604530
5.2.3Generalized performance characteristics
Sustainable disc transfer rate:
Minimum [3]73Mbytes/sec
Maximum [3]125Mbytes/sec
SCSI interface data transfer rate (asynchronous):
Maximum instantaneous one byte wide5.0MBytes/sec [3]
Maximum instantaneous two bytes wide10.0MBytes/sec [3]
Synchronous transfer rate
In low voltage differential (LVD) interface mode5.0 to 320MBytes/sec
Sector Sizes:
Default512 byte user data blocks
Variable512 to 528 bytes per sector in even number of bytes per sector.
If n (number of bytes per sector) is odd, then n-1 will be used.
Read/write consecutive sectors on a trackYes
Flaw reallocation performance impact (for flaws reallocated at format time using
Negligible
the spare sectors per sparing zone reallocation scheme)
Average rotational latency2.00 msec
Notes for Section 5.2.
[1] 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).
[2] Assumes no errors and no sector has been relocated.
[3] Assumes system ability to support the rates listed and no cable loss.
Cheetah 15K.5 SCSI Product Manual, Rev. J11
5.3Start/stop time
After DC power at nominal voltage has been applied, the drive becomes ready within 20 seconds if the Motor
Start Option is disabled (i.e., the motor starts as soon as the power has been applied). If a recoverable error
condition is detected during the start sequence, the drive executes a recovery procedure which may cause the
time to become ready to exceed 20 seconds. During spin up to ready time the drive responds to some commands over the SCSI interface in less than 3 seconds after application of power. Stop time is 30 seconds from
removal of DC power.
If the Motor Start Option is enabled, the internal controller accepts the commands listed in the SCSI Interface
Product Manual less than 3 seconds after DC power has been applied. After the Motor Start Command has
been received the drive becomes ready for normal operations within 20 seconds typically (excluding an error
recovery procedure). The Motor Start Command can also be used to command the drive to stop the spindle
(see the SCSI Commands Reference Manual).
There is no power control switch on the drive.
5.4Prefetch/multi-segmented cache control
The drive provides prefetch (read look-ahead) and multi-segmented cache control algorithms that in many
cases can enhance system performance. “Cache” as used herein refers to the drive buffer storage space when
it is used in cache operations. To select prefetch and cache features the host sends the Mode Select command
with the proper values in the applicable bytes in Mode Page 08h (see the SCSI Interface Product Manual).
Prefetch and cache operation are independent features from the standpoint that each is enabled and disabled
independently via the Mode Select command. However, in actual operation the prefetch feature overlaps
cache operation somewhat as is noted in Section 5.5.1 and Section 5.5.2.
All default cache and prefetch Mode parameter values (Mode Page 08h) for standard OEM versions of this
drive family are given in Table 10.
5.5Cache operation
Note.Refer to the SCSI 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 SCSI Interface Manual ), data requested by the host with a read com-
mand is retrieved from the buffer, if possible, before any disc access is initiated. If cache operation is not
enabled, 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 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 SCSI 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 di sc and transfers them into a se gment, 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 5.5.2 for operation from this point.
12Cheetah 15K.5 SCSI Product Manual, Rev. J
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.
5.5.1Caching write data
Write caching is a write operation by the drive that make s use of a drive b uffer storage area wher e the da ta 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 th e 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 segme nt 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 da ta 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 dat a to the med ium.
Upon completion of a Synchronize Cache command, all data received from previous write commands will have
been written to the medium.
Tables 10, 11 and 12 show the mode default settings for the drive.
5.5.2Prefetch operation
If the Prefetch feature is enabled, data in contiguous logical blocks on the disc 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 pr ef etch 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.
Cheetah 15K.5 SCSI Product Manual, Rev. J13
6.0Reliability specifications
The following reliability specifications assume correct host/drive operational interface, including all interface
timings, power supply voltages, environmental requirements and drive mounting constraints (see Section 9.4).
Seek Errors
Less than 10 in 10
Read Error Rates [1]
Recovered Data
Unrecovered Data
Miscorrected Data
Less than 10 errors in 10
Less than 1 sector in 10
Less than 1 sector in 10
Annualized Failure Rate (AFR)0.62%
Preventive MaintenanceNone required
Note.
[1] Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.
6.1Error rates
The error rates stated in this specification assume the following:
• The drive is operated per this specification using DC power as defined in this manual (see Section 7.2).
• 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.
8
seeks
12
bits transferred (OEM default settings)
16
bits transferred (OEM default settings)
21
bits transferred
6.1.1Recoverable Errors
Recoverable errors are those detected and correcte d 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 recov-
ered error specifications.
Recovered Data error rate is determined using read bits transferred for recoverab le errors occurring during a
read, and using write bits transferred for recoverable err ors occurring during a write.
6.1.2Unrecoverable Error
Unrecoverable Data Errors (Sense Key = 03h) are specified at less than 1 sector in error per 1016 bits transferred. Unrecoverable Data Errors resulting from the same cause are treated as 1 error for that block.
14Cheetah 15K.5 SCSI Product Manual, Rev. J
6.1.3Seek 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 10
8
seeks. Unrecoverable seek errors
(Sense Key = 04h) are classified as drive failures.
6.2Reliability and service
You can enhance the reliability of Cheetah 15K.5 SCSI disc drives by ensuring that the drive receives adequate cooling. Section 7.0 provides temperature measurements and other information that may be used to
enhance the service life of the drive. Section 9.3 provides recommended air-flow information.
6.2.1Annualized Failure Rate (AFR) and Mean Time Between Failures (MTBF)
These drives shall achieve an AFR of 0.62% (MTBF o f 1,400,000 hours) when operat ed in an environment th at
ensures the HDA case temperatures do not exceed the values specified in Section 7.4.1.
Operation at case temperatures outside the specifications in Section 7.4.1 may increase the AFR (dec rease
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 7.4.1 are not
exceeded.
6.2.2Preventive maintenance
No routine scheduled preventive maintenance shall be required.
Cheetah 15K.5 SCSI Product Manual, Rev. J15
6.2.3Hot plugging Cheetah 15K.5 SCSI disc drives
The ANSI SPI-4 document defines the physical requirements for removal and insertion of SCSI devices on the
SCSI bus. Four cases are addressed. The cases are differentiated by the state of the SCSI bus when the
removal or insertion occurs.
Case 1 - All bus devices powered off during removal or insertion
Case 2 - RST signal asserted continuously during removal or insertion
Case 3 - Current I/O processes not allowed during insertion or removal
Case 4 - Current I/O process allowed during insertion or removal, except on the device being changed
Seagate Cheetah 15K.5 SCSI disc drives support all four hot plugging cases. Provision shall be made by the
system such that a device being inserted makes power and ground connections prior to the connection of any
device signal contact to the bus. A device being removed shall maintain power and ground connections after
the disconnection of any device signal contact from the bus (see SFF-8451 Specification for SCA-2 Unshielded
Connections).
It is the responsibility of the systems integrator to assure that no hazards from temperature, energy, voltage, or
ESD potential are presented during the hot co nn ec t/d isc on ne ct ope ra tio n.
All I/O processes for the SCSI device being inserted or removed shall be quiescent. All SCSI devices on the
bus shall have receivers that conform to the SPI-4 standard.
If the device being hot plugged uses single-ended (SE) drive rs and the bus is currently operating in low vo ltag e
differential (LVD) mode, then all I/O processes for all devices on the bus must be co mpleted, an d the bus qu iesced, before attempting to hot plug. Following the insertion of the newly installed device, the SCSI host
adapter must issue a Bus Reset, followed by a synchronous transfer negotiation. Failure to perform the SCSI
Bus Reset could result in erroneous bus operations.
The SCSI bus termination and termination power source shall be external to the device being inserted or
removed.
End users should not mix devices with high voltage differential (HVD) drivers and receivers and devices with
SE, LVD, or multimode drivers and receivers on the same SCSI bus since the common mode voltages in the
HVD environment may not be controlled to safe levels for SE and LVD devices (see ANSI SPI-4).
The disc drive spindle must come to a complete stop prior to completely removing the drive from the cabinet
chassis. Use of the Stop Spindle command or partial withdrawal of the drive, enough to be disconnected from
the power source, prior to removal are methods for insuring that this requi rement is met. During drive insertion,
care should be taken to avoi d exceeding the lim it s st ated in Se ction 7.4.4, "Shock a nd vibration" in this m anual.
6.2.4S.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 drive degradation and is designed to provide sufficient warning of a failure
to allow data back-up before an actual failure occurs.
Note.The firmware will monitor specific attributes for degradation over time but cannot predict instanta-
neous drive failures.
Each attribute monitors a specific set of conditions in the operating performance of the drive, and the thresholds are optimized to minimize “false” predictio ns .
16Cheetah 15K.5 SCSI Product Manual, Rev. J
Controlling S.M.A.R.T.
The operating mode of S.M.A.R.T. is controlled by the DEXCPT bit and the PERF bit of the “Informational
Exceptions Control Mode Page” (1Ch). The DEXCPT bit is used to enable or disable the S.M.A.R.T. process.
Setting the DEXCPT bit will disable all S.M.A.R.T. functions. When enabled, S.M.A.R.T. will collect on-line data
as the drive performs normal read/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.
The process of measuring off-line attributes and saving data can be forced by the Rezero Unit command. Forcing S.M.A.R.T. will reset the timer so that the next scheduled interrupt will be two hours.
The drive can be interrogated by the host to determine the tim e remaining before the next schedu led measurement and data logging process will occur. This is accomplished by a log sense command to log page 0x3E.
The purpose is to allow the customer to control when S. M.A.R.T. interruptions occur. As described above, forcing S.M.A.R.T by the Rezero Unit command will reset the timer.
Performance impact
S.M.A.R.T. attribute data will be saved to the disc for the purpose of recreating the events that caused a predictive failure. The drive will measure and save parameters once every two hours subject to an idle period on the
SCSI bus. The process of measuring off-line attribute data and saving data to th e disc is uninterruptable and
the maximum delay is summarized below::
Maximum processing delay
S.M.A.R.T. delay times
On-line only delay
DEXCPT = 0, PERF = 1
42 milliseconds
Fully-enabled delay
DEXCPT = 0, PERF = 0
163 milliseconds
Reporting control
Reporting is controlled in the Informational Exceptions Control Page (1Ch). Subject to the reporting method,
the firmware will issue a 01-5D00 sense code to the host. 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 error
rate 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 rate, hence for each attribute the occurrence of an error is recorded. A counter
keeps track of the number of errors for the current interval. This counter is referred to as the Failure Counter.
Error rate is simply the number of errors per operation. The algorithm that S.M.A.R.T. uses to record rat es of
error is to set thresholds for the number of errors and the interval. If the number of errors exceeds the threshold
before the interval expires, then the error rate is considered to be unacceptable. If the number of errors does
not exceed the threshold before the interval expires, then 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 increm ented whenever th e error rate is unacceptable and decremented (not to exceed
Cheetah 15K.5 SCSI Product Manual, Rev. J17
zero) whenever the error rate is acceptable. This counter is referred to as the Failure History Counter. There is
a separate Failure History Counter for each attribute. Should the counter continually be incremented such that
it reaches the predictive threshold, a predictive failure is signaled.
6.2.5Thermal monitor
Cheetah 15K.5 SCSI 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 exceed the threatening temper at ur e va lue .
A temperature sensor monitors the drive temperature and issues a warning over the interface when the tem-
perature exceeds a set th reshold. The t emperature is measured a t power-up an d then at te n-minute interv als
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 implem ents 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 2) 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 temper ature 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 2: T emperature Log page (0Dh)
Parameter CodeDescription
0000h
0001h
Primary Temperature
Reference Temperature
When the first temperature trip point is exceeded, S.M.A.R.T. data is collected and a frame is saved to the disc.
6.2.6Drive 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
2. Short text
The most thorough option is the extended test that performs various tests on the d riv e a nd sca ns ev er y lo gic al
block address (LBA) of the drive. The short test is time-restricted and limited in length—it does not scan the
entire media surface, but does some fundamental tests and scans portions of the media.
If DST encounters an error during either of these tests, it reports a fault condition. If the drive fails the test,
remove it from service and return it to Seagate for service.
18Cheetah 15K.5 SCSI Product Manual, Rev. J
6.2.6.1DST Failure Definition
The drive will present a “diagnostic failed” condition through the self-tests results value of the diagnostic log
page if a functional failure is encountered during DST. The channel and servo parameters are not modified to
test the drive more stringently, and the number of retries are not reduced. All retries and recovery processes
are enabled during the test. If data is recoverable, no failure condition will be reported regardless of the number
of retries required to recover the data.
The following conditions are considered DST failure conditions:
• Seek error after retries are exhausted
• Track-follow error after retries are exhausted
• Read error after retries are exhausted
• Write error after retries are exhausted
Recovered errors will not be reported as diagnostic failures.
6.2.6.2Implementation
This section provides all of the information necessary to implement the DST function on this drive.
6.2.6.2.1State of the drive prior to testing
The drive must be in a ready state before issuing the Send Diagnostic command. There are multiple reasons
why a drive may not be ready, some of which are valid conditions, and not errors. For example, a drive may be
in process of doing a format, or another DST. It is the responsibility of the host application to determine the “not
ready” cause.
While not technically part of DST, a Not Ready condition also qualifies the drive to be returned to Seagate as a
failed drive.
A Drive Not Ready condition is reported by the drive under the following conditions:
• Motor will not spin
• Motor will not lock to speed
• Servo will not lock on track
• Drive cannot read configuration tables from the disc
In these conditions, the drive responds to a Test Unit Ready command with an 02/04/00 or 02/04/03 code.
6.2.6.2.2Invoking DST
To invoke DST, submit the Send Diagnostic command with the appropriate Function Code (001b for the short
test or 010b for the extended test) in bytes 1, bits 5, 6, a nd 7. Refer to the SCSI Commands Refere nce Manual,
part number 100293068, for additional information about invoking DST.
6.2.6.2.3Short and extended tests
DST has two testing options:
1. short
2. extended
These testing options are described in the following two subsections.
Each test consists of three segments: an electrical test segment, a servo test segment, and a read/verify scan
segment.
Cheetah 15K.5 SCSI Product Manual, Rev. J19
Short test (Function Code: 001b)
The purpose of the short test is to provide a time-limited test that tests as much of the drive as possible within
120 seconds. The short test does not scan the entire media surface, but does some fundamental tests and
scans portions of the media. A complete read/verify scan is not performed and only factual failures will report a
fault condition. This option provides a quick confidence test of the drive.
Extended test (Function Code: 010b)
The objective of the extended test option is to empirically test critical drive componen ts. For example, the seek
tests and on-track operations test the positioning mechanism. The read operation tests the read head element
and the media surface. The write element is tested through read/write/read operations. The integrity of the
media is checked through a read/verify scan of the media. Motor functionality is tested by default as a part of
these tests.
The anticipated length of the Extended test is reported through the Control Mode page.
6.2.6.2.4Log page entries
When the drive begins DST, it creates a new entry in the Self-test Results Log page. The new entry is created
by inserting a new self-test parameter block at the b eginning of the self- test result s log parame ter section of the
log page. Existing data will be moved to make room for the new parameter block. The drive reports 20 parameter blocks in the log page. If there are more than 20 parameter blocks, the least recent parameter block will be
deleted. The new parameter block will be initialized as follows:
1. The Function Code field is set to the same value as sent in the DST command
2. The Self-Test Results Value field is set to Fh
3. The drive will store the log page to non-volatile memory
After a self-test is complete or has been aborted, the drive updates the Self-Test Results Value field in its Self-
Te st Results Log page in non-volatile memory. The host may use Log Sense to read the results from up to the
last 20 self-tests performed by the drive. Th e se lf- te st r esults value is a 4-bit field that reports the results of the
test. If the field is zero, the drive passed with no errors detected by the DST. If the field is not zero, the test
failed for the reason reported in the field.
The drive will report the failure condition and LBA (if applicable) in the Self-test Results Log parameter. The
Sense key, ASC, ASCQ, and FRU are used to report the failure condition.
6.2.6.2.5Abort
There are several ways to abort a diagnostic. You can use a SCSI Bus Reset or a Bus Device Reset message
to abort the diagnostic.
You can abort a DST executing in background mode by using the abort code in the DST Function Code field.
This will cause a 01 (self-test aborted by the application client) code to appear in the self-test results values
log. All other abort mechanisms will be reported as a 02 (self-test routine was interrupted by a reset condition).
6.2.7Product warranty
Beginning on the date of shipment to customer and co ntin uing for a period of five years, Seagate warrants that
each product (including components and subassemblies) or sp are p art that fails to fu nction proper ly under normal use due to defect in materials on workmanship or due to nonconformance to the applicable specifications
will be repaired or replaced, at Seagate’s option and at no charge to customer, if returned by customer at customer’s expense to Seagate’s designated facility in accordance with Seagate’s warranty procedure. Seagate
will pay for transporting the repair or replacement item to customer. For more detailed warranty information
refer to the Standard terms and conditions of Purchase for Seagate products.
20Cheetah 15K.5 SCSI Product Manual, Rev. J
Shipping
When transporting or shipping a drive, a Seagate approved container must be used. Keep your original box.
They are easily identified by the Seagate-approved package label. Shipping a drive in a non-approved container voids the drive warranty.
Seagate repair centers may refuse receipt of components improperly packaged or obviously damaged in transit. Contact your Authorized Seagate Distributor to purchase additional boxes. Seagate recommends shipping
by an air-ride carrier experienced in handling computer equipment.
Product repair and return information
Seagate customer service centers are the only facilities authorized to service Seagate drives. Seagate does
not sanction any third-party repair facilities. Any unauthorized repair or tampering with the factory-seal voids
the warranty.
Cheetah 15K.5 SCSI Product Manual, Rev. J21
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