Seagate Camcorder ST3146807FC User Guide

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Cheetah 10K.6 FC Disc Drive  
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ST3146807FC  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
ST373307FC  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
ST336607FC  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Product Manual, Volume 1  
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Cheetah 10K.6 FC Disc Drive  
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ST3146807FC  
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ST373307FC  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
ST336607FC  
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Product Manual, Volume 1  
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© 2002 Seagate Technology LLC All rights reserved  
June 2002  
Publication number: 100195490, Rev. B  
Seagate, Seagate Technology, and the Seagate logo are registered trademarks of Seagate Technology LLC.  
Cheetah, SeaFAX, SeaFONE, SeaBOARD, and SeaTDD are either registered trademarks or trademarks of  
Seagate Technology LLC. Other product names are registered trademarks or trademarks of their owners.  
Seagate reserves the right to change, without notice, product offerings or specifications. No part of this publica-  
tion may be reproduced in any form without written permission of Seagate Technology LLC.  
Printed in the United States of America  
 
Revision status summary sheet  
Revision  
Date  
Writer/Engineer  
Sheets Affected  
A
B
06/18/2002  
06/26/2002  
K. Schweiss/B. Hohn  
K. Schweiss/B. Hohn  
1/1, v-viii, 1-72  
19  
Notice.  
Product Manual 100195490 is Volume 1 of a two volume document with the Fibre Channel Interface  
information in the Fibre Channel Interface Manual, part number 77767496.  
If you need the Fibre Channel Interface information, order the Fibre Channel Interface Manual, part  
number 77767496.  
 
 
Cheetah 10K.6 FC Product Manual, Rev. B  
v
Contents  
6.3.3  
 
vi  
Cheetah 10K.6 FC Product Manual, Rev. B  
10.0  
 
Cheetah 10K.6 FC Product Manual, Rev. B  
vii  
List of Figures  
Figure 25.  
 
 
Cheetah 10K.6 FC Product Manual, Rev. B  
1
1.0  
Scope  
This manual describes Seagate Technology® LLC, Cheetah® 10K.6 FC (Fibre Channel) disc drives.  
Cheetah 10K.6 FC drives support the Fibre Channel Arbitrated Loop and SCSI Fibre Channel Protocol specifi-  
cations to the extent described in this manual. The Fibre Channel Interface Manual (part number 77767496)  
describes the general Fibre Channel Arbitrated Loop characteristics of this and other Seagate Fibre Channel  
drives.  
Figure 1.  
Cheetah 10K.6 FC family disc drive  
 
     
2
Cheetah 10K.6 FC Product Manual, Rev. B  
 
Cheetah 10K.6 FC Product Manual, Rev. B  
3
2.0  
Applicable 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 opti-  
mum 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 regu-  
lation. In particular, the drive must be securely mounted in order to guarantee the specified performance char-  
acteristics. Mounting by bottom holes must meet the requirements of Section 8.5.  
2.1  
Standards  
The Cheetah 10K.6 FC family complies with Seagate standards as noted in the appropriate sections of this  
manual and the Seagate Fibre Channel Interface Manual, part number 77767496.  
The Cheetah 10K.6 FC disc drive is a UL recognized component per UL1950, CSA certified to CAN/CSA  
C22.2 No. 950-95, and VDE certified to VDE 0805 and EN60950.  
2.1.1  
Electromagnetic 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 Regula-  
tions 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 con-  
troller.  
2.1.1.1  
Electromagnetic 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 Section 5.1.1 and Table 1, DC power requirements.  
2.1.2  
Electromagnetic 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 sys-  
tem 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 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.  
 
                                   
4
Cheetah 10K.6 FC Product Manual, Rev. B  
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 Man-  
agement 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 num-  
ber, 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 Inspec-  
tion (BSMI).  
2.2  
Reference documents  
Cheetah 10K.6 FC Installation Guide  
Seagate part number: 100195492  
Fibre Channel Interface Manual  
Seagate part number: 77767496  
ANSI Fibre Channel Documents  
X3.230-1994  
X3.297.1997  
X3.303.1998  
X3.272-1996  
X3.269-1996  
NCITS TR-19  
NCITS TR-20  
SFF-8045  
FC Physical and Signaling Interface (FC-PH)  
FC-PH-2 Fibre Channel Physical and Signaling Interface-2  
FC-PH-3 Fibre Channel Physical and Signaling Interface-3  
FC Arbitrated Loop (FC-AL)  
Fibre Channel Protocol for SCSI (FCP)  
Private Loop SCSI Direct Attach (PLDA)  
Fabric Loop Attachment (FC-FLA)  
Specification for 40-pin SCA-2 Connector with Parallel Selection  
Specification for 40-pin SCA-2 Connector with Bidirectional Enclosure Services  
Interface  
SFF-8067  
ANSI Small Computer System Interface (SCSI) Documents  
X3.131-1994  
X3.270-1996  
(SCSI-2)  
(SCSI-3) Architecture Model  
NCITS 305-199X (SCSI-3) Enclosure Services  
Specification for Acoustic Test Requirement and Procedures  
Seagate part number: 30553-001  
Package Test Specification  
Package Test Specification  
Seagate P/N 30190-001 (under 100 lb.)  
Seagate P/N 30191-001 (over 100 lb.)  
In case of conflict between this document and any referenced document, this document takes precedence.  
 
                     
Cheetah 10K.6 FC Product Manual, Rev. B  
5
3.0  
General description  
Cheetah 10K.6 FC drives combine giant magnetoresistive (GMR) heads, partial response/maximum likelihood  
(PRML) read channel electronics, embedded servo technology, and a Fibre Channel interface to provide high  
performance, high capacity data storage for a variety of systems including engineering workstations, network  
servers, mainframes, and supercomputers.  
Cheetah 10K.6 FC drives are random access storage devices designed to support the Fibre Channel Arbi-  
trated Loop (FC-AL) and SCSI Fibre Channel Protocol as described in the ANSI specifications, this document,  
and the Fibre Channel Interface Manual (part number 77767496) which describes the general interface char-  
acteristics of this drive. Cheetah 10K.6 FC drives are classified as intelligent peripherals and provide level 2  
conformance (highest level) with the ANSI SCSI standard.  
See Figure 2 for an exploded view of the drive. Never disassemble the HDA. This exploded view is for informa-  
tion only. Do not attempt to service items in the sealed enclosure (heads, media, actuator, etc.) as this requires  
special facilities. The drive contains no parts replaceable by the user and opening the HDA for any reason  
voids your warranty.  
Figure 2.  
Cheetah 10K.6 FC disc drive  
Cheetah 10K.6 FC drives use a dedicated landing zone at the innermost radius of the media to eliminate the  
possibility of destroying or degrading data by landing in the data zone. The heads automatically go to the land-  
ing zone when power is removed from the drive.  
An automatic shipping lock prevents potential damage to the heads and discs that results from movement dur-  
ing shipping and handling. The shipping lock disengages and the head load process begins when power is  
applied to the drive.  
Cheetah 10K.6 FC drives decode track 0 location data from the servo data embedded on each surface to elim-  
inate 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.  
 
       
6
Cheetah 10K.6 FC Product Manual, Rev. B  
3.1  
Standard features  
Cheetah 10K.6 FC drives have the following standard features:  
• Integrated dual port FC-AL controller  
• Concurrent dual port transfers  
• Support for FC arbitrated loop, private and public attachment  
• Differential copper FC drivers and receivers  
• Downloadable firmware using the FC-AL interface  
• Supports SCSI enclosure services via interface connector  
• 128-deep task set (queue)  
• Supports up to 32 initiators  
• Drive selection ID and configuration options are set on the FC-AL backpanel or through interface com-  
mands. Jumpers are not used on the drive.  
• Fibre Channel worldwide name uniquely identifies the drive and each port  
• User-selectable logical block size (512 to 528 bytes per logical block) in even numbers of blocks  
• Selectable frame sizes from 256 to 2,112 bytes  
• Industry standard 3.5-inch low profile form factor dimensions  
• Programmable logical block reallocation scheme  
• Flawed logical block reallocation at format time  
• Programmable auto write and read reallocation  
• Reed-Solomon error correction code  
• Sealed head and disc assembly (HDA)  
• No preventive maintenance or adjustments required  
• Dedicated head landing zone  
• Automatic shipping lock  
• Embedded Grey Code track address and servo wedge address to eliminate seek errors  
• Self-diagnostics performed at power on  
• 1:1 interleave  
• Zone bit recording (ZBR)  
• Vertical, horizontal, or top down mounting  
• Dynamic spindle brake  
• 8,192 Kbyte data buffer. See Section 4.5.  
• Embedded servo design  
• Reallocation of defects on command (Post Format)  
• Fibre Channel interface transports SCSI protocol  
3.2  
Media description  
The media used on the drive has a diameter of approximately 84 mm (approximately 3.3 inches). The alumi-  
num substrate is coated with a thin film magnetic material, overcoated with a proprietary protective layer for  
improved durability and environmental protection.  
3.3  
Performance  
• Programmable multi-segmentable cache buffer  
• 200 Mbytes/sec maximum instantaneous data transfers per port  
• 10K RPM spindle; average latency = 2.99 msec  
• Command queuing of up to 128 commands  
• Background processing of queue  
• Supports start and stop commands  
• Adaptive seek velocity; improved seek performance  
3.4  
Reliability  
• 1,200,000 hour MTBF  
• LSI circuitry  
• Balanced low mass rotary voice coil actuator  
 
                                               
Cheetah 10K.6 FC Product Manual, Rev. B  
7
• Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.)  
• Dithering  
3.5  
Unformatted and formatted capacities  
Formatted capacity depends on the spare reallocation sectors scheme selected, the number of data tracks per  
sparing zone, and the number of alternate sectors (LBAs) per sparing zone. The following table shows the  
standard OEM model capacity:  
Formatted  
Unformatted  
ST3146807FC  
ST373307FC  
ST336607FC  
11177330h (146.8) Gbytes (190.0) Gbytes  
88BB998h (73.3) Gbytes  
445DCCCh (36.7) Gbytes  
(95.0) Gbytes  
(47.5) Gbytes  
Standard OEM models are formatted to 512 bytes per block. You can order other capacities by requesting a dif-  
ferent sparing scheme and logical block size.  
The sector size is selectable at format 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. Cheetah  
10K.6 FC drives use a zone sparing scheme. The drive is divided into frequency zones with a variable number  
of spares in each zone.  
Note. For 2 gigabit operation, sector sizes must be divisible by 8.  
3.6  
Programmable 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 Fibre Channel Interface Manual, part number 7767496. 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.  
3.7  
OEM standard drives are shipped with the Cheetah 10K.6 FC Installation Guide (part number 100195492).  
3.8 Factory-installed options  
Factory-installed accessories  
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 Cheetah 10K.6 FC Installation Guide, part number 100195492, 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.  
3.9  
User-installed accessories  
The following accessories are available. All kits may be installed in the field.  
• Evaluation kit, part number 73473641.  
This kit provides an adapter card (“T-card”) to allow cable connections for two FC ports and DC power.  
• Single-unit shipping pack.  
 
                   
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Cheetah 10K.6 FC Product Manual, Rev. B  
 
Cheetah 10K.6 FC Product Manual, Rev. B  
9
4.0  
Performance characteristics  
This section provides detailed information concerning performance-related characteristics and features of  
Cheetah 10K.6 FC drives.  
4.1  
Internal drive characteristics  
ST3146807FC...........ST373307FC..........ST336607FC  
Drive capacity  
Read/write data heads  
Bytes per track  
146.8.........................73.3 ........................36.7........... Gbytes (formatted, rounded off value)  
8................................4 .............................2  
368............................368 .........................368............ Kbytes (average, rounded off values)  
1,835.........................1,835 ......................1,835......... Mbytes (unformatted, rounded off value)  
Bytes per surface  
Tracks per surface (total) 49,855.......................49,855 ....................49,855....... Tracks (user accessible)  
Tracks per inch  
64,000.......................64,000 ....................64,000....... TPI  
Peak bits per inch  
Internal data rate  
Disc rotation speed  
Avg rotational latency  
570............................570 .........................570............ KBPI  
475-841.....................475-841 ..................475-841..... Mbits/sec (variable with zone)  
10,008.......................10,008 ....................10,008....... rpm (+ 0.5%)  
2.99...........................2.99 ........................2.99........... msec  
4.2  
Seek performance characteristics  
Access time  
4.2.1  
Including controller  
Not including controller  
overhead 1,2 (msec)  
1 2  
,
overhead  
(msec)  
Read  
Write  
Read  
Write  
3 4  
,
Average  
Typical  
4.90  
0.55  
9.20  
5.50  
0.75  
9.70  
4.70  
0.35  
9.00  
5.30  
0.55  
9.50  
Single track Typical3,4  
Full stroke  
Typical3,4  
1.  
2.  
3.  
Execution time measured from receipt of the FCP Command to the FCP Response.  
Assumes no errors and no sector has been relocated.  
Typical access times are measured under nominal conditions of temperature, voltage, and hor-  
izontal orientation as measured on a representative sample of drives.  
Access time = controller overhead + average seek time.  
4.  
Access to data = controller overhead + average seek time + latency time.  
4.2.2  
Format command execution time (in minutes)  
ST3146807FC  
ST373307FC  
ST336607FC  
Maximum (with verify)  
180  
90  
90  
45  
45  
30  
Maximum (without verify)  
 
                                                       
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Cheetah 10K.6 FC Product Manual, Rev. B  
4.2.3  
General performance characteristics  
Minimum sector interleave  
1 to 1  
Data buffer to/from disc media (one 512-byte logical block)*  
Minimum  
Average  
Maximum  
59 MBytes/sec  
94 MBytes/sec  
105 MBytes/sec  
Fibre Channel Interface maximum instantaneous transfer rate  
1 GHz  
2 GHz  
106 Mbytes/sec* per 212 Mbytes/sec* per  
port (dual port = 212 port (dual port = 424  
Mbytes/sec*)  
Mbytes/sec*)  
Logical block sizes  
Default is 512-byte data blocks  
Variable 512 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 track  
Yes  
Flaw reallocation performance impact (for flaws reallocated at format time  
using the spare sectors per sparing zone reallocation scheme.)  
Negligible  
0.8 msec  
Overhead time for head switch in sequential mode  
Overhead time for one track cylinder switch in sequential mode  
Average rotational latency  
1.2 msec (typical)  
2.99 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.  
4.3  
Start/stop time  
If the Motor Start option is disabled, the drive becomes ready within 20 seconds after DC power is applied. If a  
recoverable error condition is detected during the start sequence, the drive executes a recovery procedure and  
the time to become ready may exceed 30 seconds. Stop time is less than 30 seconds (maximum) from removal  
of DC power.  
If the Motor Start option is enabled, the internal controller accepts the commands listed in the Fibre Channel  
Interface 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 (excluding the error recovery  
procedure). The Motor Start command can also be used to command the drive to stop the spindle.  
There is no power control switch on the drive.  
4.4  
Prefetch/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 opera-  
tion, 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 15.  
4.5  
Cache operation  
Note. Refer to the Fibre Channel Interface Manual for more detail concerning the cache bits.  
Of the 8,192 kbytes physical buffer space in the drive, 6,877 kbytes can be used as a cache.  
 
                                   
Cheetah 10K.6 FC Product Manual, Rev. B  
11  
The buffer can be divided into logical segments (using Mode Select Page 08h, byte 13) 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 Fibre Channel Interface Manual), data requested by the host with a read  
command is retrieved from the buffer, if possible, before any disc access is initiated. If cache operation is not  
enabled, the buffer (still segmented with the required number of segments) 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. On a cache  
miss, all data transfers to the host are in accordance with buffer-full ratio rules. On a cache hit, the drive ignores  
the buffer-full ratio rules. See the explanation provided with the information about Mode Page 02h (disconnect/  
reconnect control) in the Fibre Channel Interface Manual.  
The following is a simplified description of the prefetch/cache operation:  
Case A—read command is received and the first logical block is already in the cache:  
1. Drive transfers to the initiator the first logical block requested plus all subsequent contiguous logical blocks  
that are already in the cache. This data may be in multiple segments.  
2. When a requested logical block is reached that is not in any cache segment, the drive fetches it and any  
remaining requested logical block addresses from the disc and puts them in a segment of the cache. The  
drive transfers the remaining requested logical blocks from the cache to the host in accordance with the  
Mode Select Disconnect/Reconnect parameters, page 02h.  
3. If the prefetch feature is enabled, refer to section 4.5.2 for operation from this point.  
Case B—A Read command requests data, and the first logical block is not in any segment of the cache:  
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.  
During a prefetch, the drive crosses a cylinder boundary to fetch data only if the Discontinuity (DISC) bit is set  
to 1 in bit 4 of byte 2 of the Mode Select parameters page 08h. Default is zero for bit 4.  
Each cache segment is actually a self-contained circular buffer whose length is an integer number of logical  
blocks. The wrap-around capability of the individual segments greatly enhances the cache’s overall perfor-  
mance, allowing a wide range of user-selectable configurations. The drive supports operation of any integer  
number of segments from 1 to 32. Divide the 6,877 Kbytes in the buffer by the number of segments to get the  
segment size in bytes; then divide by the sector size to get the number of sectors per segment, any partial sec-  
tors remaining are not used. Default is 3 segments.  
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 specifi-  
cation 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.  
4.5.1  
Caching 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 avail-  
able 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  
 
           
12  
Cheetah 10K.6 FC Product Manual, Rev. B  
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 gen-  
erated.  
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 15 shows the mode default settings for the drive.  
4.5.2  
Prefetch 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 opera-  
tion 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.  
Since data that is prefetched replaces data already in some buffer segments, the host can limit the amount of  
prefetch data to optimize system performance. The Max Prefetch field (bytes 8 and 9) limits the amount of  
prefetch. The drive does not use the Prefetch Ceiling field (bytes 10 and 11).  
During a prefetch operation, the drive crosses a cylinder boundary to fetch more data only if Mode parameters  
page 08h, byte 2, bit 4 is set to 1 (Discontinuity--DISC bit).  
When prefetch (read look-ahead) is enabled (enabled by DRA = 0), it operates under the control of ARLA  
(Adaptive Read Look-Ahead). If the host uses software interleave, ARLA enables prefetch of contiguous blocks  
from the disc when it senses that a prefetch hit will likely occur, even if two consecutive read operations were  
not for physically contiguous blocks of data (e.g. “software interleave”). ARLA disables prefetch when it decides  
that a prefetch hit will not likely occur. If the host is not using software interleave, and if two sequential read  
operations are not for contiguous blocks of data, ARLA disables prefetch, but as long as sequential read oper-  
ations request contiguous blocks of data, ARLA keeps prefetch enabled.  
4.5.3  
Optimizing cache performance for desktop and server applications  
Desktop and server applications require different drive caching operations for optimal performance. This  
means it is difficult to provide a single configuration that meets both of these needs. In a desktop environment,  
you want to configure the cache to respond quickly to repetitive accesses of multiple small segments of data  
without taking the time to “look ahead” to the next contiguous segments of data. In a server environment, you  
want to configure the cache to provide large volumes of sequential data in a non-repetitive manner. In this  
case, the ability of the cache to “look ahead” to the next contiguous segments of sequential data is a good  
thing.  
The Performance Mode (PM) bit controls the way the drive switches the cache buffer into different modes of  
segmentation. In “server mode” (PM bit = 0), the drive can dynamically change the number of cache buffer seg-  
ments as needed to optimize the performance, based on the command stream from the host. In “desktop  
mode” (PM bit = 1), the number of segments is maintained at the value defined in Mode Page 8, Byte 13, at all  
times. For additional information about the PM bit, refer to the Unit Attention Parameters page (00h) of the  
Mode Sense command (1Ah) in the Fibre Channel Interface Product Manual, part number 77767496.  
 
   
Cheetah 10K.6 FC Product Manual, Rev. B  
13  
5.0  
Reliability specifications  
The following reliability specifications assume correct host and drive operational interface, including all inter-  
face timings, power supply voltages, environmental requirements and drive mounting constraints  
Less than 10 errors in 108 seeks  
Seek error rate  
Read Error Rates1  
Recovered Data  
Less than 10 errors in 1012 bits transferred (OEM default settings)  
Less than 1 sector in 1015 bits transferred  
Less than 1 sector in 1021 bits transferred  
Less than 1 error in 1012 bits transferred with minimum receive eye  
Less than 1 error in 1014 bits transferred with typical receive eye  
Unrecovered Data  
Miscorrected Data  
Interface error rate  
MTBF  
1,200,000 hours  
5 years  
Service life  
Preventive maintenance  
None required  
1. Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.  
5.1 Error rates  
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  
• The drive has been formatted with the FC-AL Format command.  
• Errors caused by media defects or host system failures are excluded from error rate computations.  
• Assume random data.  
5.1.0.1  
Interface 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. The total error rate for a loop of devices is the sum of the individual device error  
rates.  
5.1.1  
Environmental interference  
When evaluating systems operation under conditions of electromagnetic interference (EMI), the performance  
of the drive within the system is considered acceptable if the drive does not generate an unrecoverable condi-  
tion.  
An unrecoverable error, or condition, is defined as one that:  
• is not detected and corrected by the drive itself  
• is not detected from the error or fault status provided through the drive or FC-AL interface  
• is not recovered by normal drive or system recovery procedures without operator intervention  
5.1.2  
Write errors  
Write errors can occur as a result of media defects, environmental interference, or equipment malfunction.  
Therefore, write errors are not predictable as a function of the number of bits passed.  
If an unrecoverable write error occurs because of an equipment malfunction in the drive, the error is classified  
as a failure affecting MTBF. Unrecoverable write errors are those that cannot be corrected within two attempts  
at writing the record with a read verify after each attempt (excluding media defects).  
5.1.3  
Seek 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 (15h) is reported with a Medium error (3h) or Hardware error (4h) reported in the  
 
                                                     
14  
Cheetah 10K.6 FC Product Manual, Rev. B  
Sense Key. This is an unrecoverable seek error. Unrecoverable seek errors are classified as failures for MTBF  
calculations. Refer to the Fibre Channel Interface Manual, part number 77767496, for Request Sense informa-  
tion.  
5.2  
Reliability and service  
You can enhance the reliability of Cheetah 10K.6 FC disc drives by ensuring that the drive receives adequate  
cooling. Section 6.0 provides recommended air-flow information, temperature measurements, and other infor-  
mation, which you can use to enhance the service life of the drive.  
5.2.1  
Mean time between failure (MTBF)  
The production disc drive achieves an MTBF of 1,200,000 hours when operated in an environment that  
ensures the case temperatures specified in Section 6.3.1 are not exceeded. Short-term excursions up to the  
specification limits of the operating environment will not affect MTBF performance. Operating the drive at case  
temperatures above these values will adversely affect the drive’s ability to meet specifications. See Section Fig-  
The MTBF target is specified as device power-on hours (POH) for all drives in service per failure.  
The following expression defines MTBF:  
MTBF per measurement period = Estimated power-on operating hours in the period  
Number of drive failures in the period  
Estimated power-on operating hours means power-on hours per disc drive times the total number of disc drives  
in service. Each disc drive must have accumulated at least nine months of operation. Data is calculated on a  
rolling average base for a minimum period of six months.  
MTBF is based on the following assumptions:  
• 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 6.3.1 are not  
exceeded.  
Drive failure means any stoppage or failure to meet defined specifications caused by drive malfunction.  
A S.M.A.R.T. predictive failure indicates that the drive is deteriorating to an imminent failure and is considered  
an MTBF hit.  
5.2.2  
Preventive maintenance  
No routine scheduled preventive maintenance is required.  
5.2.3  
Service life  
The drive has a useful service life of five 5 years. Depot repair or replacement of major parts is permitted dur-  
ing the lifetime.  
5.2.4  
Service philosophy  
Special equipment is required to repair the drive HDA. To achieve the above service life, repairs must be per-  
formed only at a properly equipped and staffed Seagate service and repair facility. Troubleshooting and repair  
of PCBs in the field is not recommended because of the extensive diagnostic equipment required for effective  
servicing. There are not spare parts available for this drive. The drive warranty is voided if the HDA is opened.  
5.2.5  
Service tools  
No special tools are required for site installation or recommended for site maintenance. Refer to Section 5.2.4.  
The depot repair philosophy of the drive precludes the necessity for special tools. Field repair of the drive is not  
practical because users cannot purchase individual parts for the drive.