W D E 9 1 0 0 - 0 0 1 6 E N T E R P R WESTERN DIGITAL
Native| Translation
------+-----+-----+-----
Form 3.5"/SLIMLINE Cylinders 6932| | |
Capacity form/unform 9105/ MB Heads 12| | |
Seek time / track 8.0/ 1.0 ms Sector/track | | |
Controller SCSI3 SI/WI/ULTR/FAS Precompensation
Cache/Buffer 1024 KB ADAP./SEGMEN Landing Zone
Data transfer rate 10.000 MB/S int Bytes/Sector 512
40.000 MB/S ext SYNC
Recording method PRML 0/4/4 operating | non-operating
-------------+--------------
Supply voltage 5/12 V Temperature *C 5 55 | -40 60
Power: sleep W Humidity % 10 90 | 5 95
standby W Altitude km -0.300 3.000| -0.300 12.000
idle 9.2 W Shock g 10 | 70
seek 11.8 W Rotation RPM 7200
read/write W Acoustic dBA
spin-up W ECC Bit 144BIT REED SOLOMON,SMART
MTBF h 1000000
Warranty Month 60
Lift/Lock/Park YES Certificates
**********************************************************************
L A Y O U T
**********************************************************************
WESTERN WDE9100 INSTALLATION GUIDE 4079-001055 REV. B 10/97
+-LED-----------------------------------------------------+
|+-+ |XX
|| | Option Block |XXPOWER
|| | |xx
|| | |
|| | |XX1
|1-+ |XX
| |XX
| |XX
| 50-Pin Version |XX
| |XX
| |XX
| |XX
| |XX
| |XX SCSI
| |XX I/O
| |XX
+---------------------------------------------------------+
+LED------------------------------------------------------+ 69
|+-+ |XX Power
|| | Option Block |XX
|| | |+-+Remote
|| | || |Option
|| | |+-+Block
|1-+ |XX1
| |XX
| |XX
| 68-Pin |XX
| |XX
| |XX
| |XX
| |XX
| |XX SCSI
| |XX I/O
| |XX
+---------------------------------------------------------+
+-LED-----------------------------------------------------+
|+-+ |
|| | Option Block |
|| | |
|| | |XX
|| | |XX
|1-+ |XX
| |XX
| |XX
| 80-Pin |XX
| |XX SCSI
| |XX I/O
| |XX
| |XX
| |XX
| |
| |
+---------------------------------------------------------+
-------------------------------------------------
| |
| |
| +-----/41-------------------------80\-----+ |
| | / ||||||||||||||||||||||||||||| \ | |
| +----+-1---------------------------40+----+ |
---------------SCA-2 80-Pin Connector------------
**********************************************************************
J U M P E R S
**********************************************************************
WESTERN WDE9100 INSTALLATIN GUIDE 4079-001055 REV. B 10/97
Jumper Setting
==============
Option Block Functions
----------------------
The firmware uses several pins on the option block to modify the
drive characteristics. The definitions for the jumpers follow:
- SCSI ID: Four jumpers are used to identify the default SCSI ID for
the drive.
- Disable Auto Start: Use of this jumper disables Auto Start,
meaning the drive does not spin-up until a START UNIT command is
issued. Without this jumper, the drive will spin-up and prepare
itself at power on without having to receive a START UNIT command.
- Auto Start Delay: Use of this jumper allows the Auto Start to
incorporate a delay. The delay time equals the SCSI ID multiplied
by 4 seconds.
- Disable Target Initiated Synchronous/Wide Negotiation: Use of this
jumper dictates that the drive cannot initiate either synchronous
negotiation or wide negotiation. Without this jumper, the drive
initiates synchronous and wide negotiation when appropriate.
- Disable Unit Attention: This controls whether a CHECK CONDITION
status is reported following a Power On or Reset sequence. A
REQUEST SENSE command following one of those conditions still
yields the correct sense data for the UNIT ATTENTION condition, as
sense data is generated regardless of the jumper setting. A jumper
on this pin disables the generation of a CHECK CONDITION for the
Power On and Reset UNIT ATTENTION conditions. With no jumper
attached, a CHECK CONDITION status is reported in these situations.
- SCSI Configure Automatically (SCAM): The drive is SCAM levels 1
and 2 compliant, which eases user configuration of SCSI IDs and
allows for hot plugging on single and multiple drive systems. Use
of this jumper allows the drive to function as a SCAM level 2
device. Without the jumper the drive is not a SCAM device.
- Active SCSI Termination: To ensure reliable communication, the
SCSI bus must be properly terminated. Use of this jumper enables
active termination on the drive. Without this jumper, active
termination is disabled.
The option block
----------------
The WD Enterprise drive PCBA contains an option block that controls
the drive's operation. This block is equipped with jumper pins that
correspond to various options controlled by SCSI commands. Jumpers
are used to enable or disable the options and modify the
drive configuration.
Note: Whenever you change a jumper setting, it will take effect the
next time the drive is powered on.
Option Block Pin Assignments
----------------------------
The option block is used to modify the drive characteristics and
make connections to external devices.
+----------------+------+------------------------------------------+
|OPTION/SIGNAL |PINS |CONFIGURATION NOTES |
|SCSI ID |01-08 | |
+----------------+------+------------------------------------------+
|(KEY)/LED- | X-10 |X - NO PIN/10 - LED CATHODE CONNECTION |
+----------------+------+------------------------------------------+
|RESERVED |11-12 |11 - GROUND/12 - LED ANODE CONNECTION |
+----------------+------+------------------------------------------+
|OPT 1: DISABLE |13-14 |INSTALL JUMPER TO DISABLE AUTO START |
|AUTO START | | |
+----------------+------+------------------------------------------+
|OPT 2: AUTO |15-16 |INSTALL JUMPER TO ENABLE AUTO START DELAY |
|START DELAY | | |
+----------------+------+------------------------------------------+
|OPT 3: SCAM |17-18 |INSTALL JUMPER TO ENABLE SCAM |
+----------------+------+------------------------------------------+
|OPT 4: DISABLE |19-20 |INSTALL JUMPER TO DISABLE UNIT ATTENTION |
|UNIT ATTENTION | | |
+----------------+------+------------------------------------------+
|OPT 5: DISABLE |21-22 |INSTALL JUMPER TO DISABLE TARGET INITIATED|
|TARGET INITIATED| |SYNCHRONOUS/WIDE NEGOTATION |
|SYNCHRONOUS/WIDE| | |
|NEGOTATION | | |
+----------------+------+------------------------------------------+
|OPT 6: SCSI |23-24 |INSTALL JUMPER TO ENABLE SCSI TERMINATION |
|TERMINATION | | |
+----------------+------+------------------------------------------+
|TXD/RXD |25-26 |RESERVED |
+----------------+------+------------------------------------------+
|TPWR/+5V |27-28 |INSTALL JUMPER TO ENABLE TERMPWR ON THE |
| | |SCSI BUS |
+----------------+------+------------------------------------------+
|LED+/+5V |29-30 |29 - LED ANODE CONNECTION / 30 - RESERVED |
+----------------+------+------------------------------------------+
|+12R/+12R |31-32 |RESERVED |
+----------------+------+------------------------------------------+
|+12V/+12V |33-34 |RESERVED |
+----------------+------+------------------------------------------+
NOTE
Pins 1, 3, 5, 7, 11, 13, 15, 17, 19, 21, and 23 are ground.
SCSI ID Numbers
---------------
Each device on the SCSI bus requires a unique SCSI ID number
(0 to 7 for 8-bit drives, 0 to 15 for 16-bit drives). Option
block pin 1 through 8 are used to set the SCSI IDs. The host
computer's SCSI controller typically uses ID number 7, and the other
numbers are used for devices such as hard drives. The WD Enterprise
has a default SCSI ID of 0.
SCSI ID 8-bit
-------------
+----------+-----------------------+
| SCSI ID | Jumpers |
| | 5&6 | 3&4 | 1&2 |
+----------+-------+-------+-------+
|x 0 | OPEN | OPEN | OPEN |
+----------+-------+-------+-------+
| 1 | OPEN | OPEN | CLOSED|
+----------+-------+-------+-------+
| 2 | OPEN | CLOSED| OPEN |
+----------+-------+-------+-------+
| 3 | OPEN | CLOSED| CLOSED|
+----------+-------+-------+-------+
| 4 | CLOSED| OPEN | OPEN |
+----------+-------+-------+-------+
| 5 | CLOSED| OPEN | CLOSED|
+----------+-------+-------+-------+
| 6 | CLOSED| CLOSED| OPEN |
+----------+-------+-------+-------+
| 7 | CLOSED| CLOSED| CLOSED|
+----------+-------+-------+-------+
SCSI ID - 16-bit
----------------
+----------+-------------------------------+ 80-Pin
| SCSI ID | Jumper Location | Pin 39 SCSI ID 0
| | PINS | Pin 40 SCSI ID 2
| | 7-8 | 5-6 | 3-4 | 1-2 | Pin 79 SCSI ID 1
+----------+-------+-------+-------+-------+ Pin 80 SCSI ID 3
| 0 | OPEN | OPEN | OPEN | OPEN |
+----------+-------+-------+-------+-------+ Pin 01 +12V
| 1 | OPEN | OPEN | OPEN | CLOSED| 02 +12V
+----------+-------+-------+-------+-------+ 03 +12V
| 2 | OPEN | OPEN | CLOSED| OPEN | 04 +12V
+----------+-------+-------+-------+-------+ 41 +12V GND
| 3 | OPEN | OPEN | CLOSED| CLOSED| 42 +12V GND
+----------+-------+-------+-------+-------+ 43 +12V GND
| 4 | OPEN | CLOSED| OPEN | OPEN | 44 MATED1
+----------+-------+-------+-------+-------+ 34-36 +5V
| 5 | OPEN | CLOSED| OPEN | CLOSED| 74 GND
+----------+-------+-------+-------+-------+ 75 +5V GND
| 6 | OPEN | CLOSED| CLOSED| OPEN | 76 +5V GND
+----------+-------+-------+-------+-------+
| 7 | OPEN | CLOSED| CLOSED| CLOSED|
+----------+-------+-------+-------+-------+
| 8 | CLOSED| OPEN | OPEN | OPEN |
+----------+-------+-------+-------+-------+
| 9 | CLOSED| OPEN | OPEN | CLOSED|
+----------+-------+-------+-------+-------+
| 10 | CLOSED| OPEN | CLOSED| OPEN |
+----------+-------+-------+-------+-------+
| 11 | CLOSED| OPEN | CLOSED| CLOSED|
+----------+-------+-------+-------+-------+
| 12 | CLOSED| CLOSED| OPEN | OPEN |
+----------+-------+-------+-------+-------+
| 13 | CLOSED| CLOSED| OPEN | CLOSED|
+----------+-------+-------+-------+-------+
| 14 | CLOSED| CLOSED| CLOSED| OPEN |
+----------+-------+-------+-------+-------+
| 15 | CLOSED| CLOSED| CLOSED| CLOSED|
+----------+-------+-------+-------+-------+
Remote Option for 68-Pin Connector
----------------------------------
Signal Name | SFF-8009 | SFF-8009 | Pin Number
| Signal Name| Pin Number|
--------------+------------+-----------+-----------
SCSI ID 0 | SEL0- | 1 | 69
--------------+------------+-----------+-----------
SCSI ID 1 | SEL1- | 3 | 71
--------------+------------+-----------+-----------
SCSI ID 2 | SEL2- | 5 | 73
--------------+------------+-----------+-----------
SCSI ID 3 | SEL3- | 7 | 75
--------------+------------+-----------+-----------
TERMEN- | ENTERM- | 9 | 77
--------------+------------+-----------+-----------
+5V | +5V | 11 | 79
--------------+------------+-----------+-----------
| | |
--------------+------------+-----------+-----------
GND/OPEN | XTFALT- | 2 | 70
--------------+------------+-----------+-----------
GROUND | VUNIQ- | 4 | 72
--------------+------------+-----------+-----------
GND/OPEN | GND/OPEN | 6 | 74
--------------+------------+-----------+-----------
LED- | XTACTV- | 8 | 10
--------------+------------+-----------+-----------
GROUND | GROUND | 10 | 78
--------------+------------+-----------+-----------
NO CONNECTION | FAULT- | 12 | 80
**********************************************************************
I N S T A L L
**********************************************************************
WESTERN WDE9100 INSTALLATION GUIDE 4079-001055 REV. B 10/97
Notes on installation
=====================
Installation direction
----------------------
horizontally vertically
+-----------------+ +--+ +--+
| | | +-----+ +-----+ |
| | | | | | | |
+-+-----------------+-+ | | | | | |
+---------------------+ | | | | | |
| | | | | |
| | | | | |
+---------------------+ | +-----+ +-----+ |
+-+-----------------+-+ +--+ +--+
| |
| |
+-----------------+
The drive will operate in all axis (6 directions).
Mounting
--------
The WDE9100 features side and bottom mounting holes, which allow the
drive to be mounted in any orientation.
The hard drive is a precision mechanical assembly. Improper mounting
may distort the drive frame and/or amplify shock and vibration inputs
resulting in degraded drive performance. For instructions on
installing the drive, including drive handling and mounting, refer to
the WD Enterprise Installation Guide (document number 4079-001057).
Operating Shock
---------------
WD Enterprise drives are tested by applying a linear shock in each
axis, one axis at a time, at a rate not exceeding two shocks per
second.
Non-operating Shock
-------------------
WD Enterprise drives are tested by applying a linear shock in each
axis, one axis at a time. A maximum of three shocks per axis is
applied.
Non-operating Rotational Shock
------------------------------
WD Enterprise drives are tested by applying a rotational shock in
each direction, about each axis, one axis at a time.
Operating Vibration
-------------------
WD Enterprise drives are tested by applying a continuous swept sine
excitation in each linear axis, one axis at a time. Sweep rate is
0.25 octave per minute.
Non-operating Vibration
-----------------------
Note: This specification applies to handling and transportation of
unmounted drives.
Drives are tested by applying a continuous swept sine excitation in
each linear axis, one axis at a time. Sweep rate is one octave per
minute.
Packaged Shock and Vibration
----------------------------
The shipping packaging is designed to meet the National/International
Safe Transit Association (N/ISTA) standards for packaged products.
The drive incurs no physical damage when subjected to the N/ISTA
standards.
Cooling
-------
Sustained operation at temperatures in excess of the reliability
values degrades the MTBF rating. Short excursions up to, but not
exceeding, the maximum values will not affect the MTBF rating.
Maximum component temperature ratings must not be exceeded under any
operating condition. The drive may require forced air cooling to meet
specified operating temperatures.
Read Caching and Pre-Fetch
--------------------------
Read caching allows the drive to maintain data in the cache for quick
transfer to the host when a media access is not required.
Pre-fetching takes place after a media access when the drive reads
data into the cache that the firmware determines is likely to be
requested by the host. Refer to the Western Digital SCSI
Implementation Guide (document number 4096-001343) for further
details.
Write Caching
-------------
Write caching gives the host the ability to allow the drive to
asynchronously write data to the media while other processes occur.
Refer to the Western Digital SCSI Implementation Guide (document
number 4096-001343) for further details.
Write Coalescing
----------------
Write coalescing allows the drive to combine write commands that
write data to sequential portions of the media into one operation.
This feature improves performance by reducing the number of
revolutions needed to write data to the media. Refer to the Western
Digital SCSI Implementation Guide (document number 4096-001343) for
further details.
Serpentine Seek Technology
--------------------------
Western Digital's Serpentine seek technology effectively reduces the
overhead associated with actuator movement, thereby increasing
sustained data throughput. Serpentine seek technology alters the
traditional hard drive format to create a "winding" track-to-track
pattern. This unique pattern emphasizes short, quick actuator
movements that occur in a predictable fashion. This enhances the
drive's ability to keep data streaming on and off the media with
minimal disruption.
512 Kilobyte Data Buffer
------------------------
The entire data buffer is user accessible, enabling powerful data
caching capabilities.
Adaptive Caching
----------------
The WDE9100 is equipped with an adaptive caching capability which
enables the drive to improve performance and throughput based on how
the drive is being used. Each drive determines the environment in
which it is being used and optimizes the way it handles commands and
data.
Command Queuing and Reordering
------------------------------
The WDE9100 supports both tagged and untagged queuing. Tagged queuing
allows the drive to receive multiple I/O processes from each
initiator. Untagged queuing allows the drive to receive a maximum of
one I/O process from each initiator.
In order to use tagged command queuing, the initiator must set the
disconnect privilege bit. This allows the drive to disconnect from
the SCSI bus. It also allows the same or other initiators to connect
to the drive and send additional commands. The drive returns a status
of BUSY if the disconnect privilege bit is off and the drive has I/O
processes in the command queue. The drive has the capability to queue
up to 64 I/O processes. Upon receipt of the 65th I/O process, the
drive returns a status of QUEUE FULL.
The drive can reorder I/O processes in the command queue. The order
in which the drive executes I/O processes may differ from the order
in which they were received.
Command reordering employs an algorithm which improves the throughput
of the drive by attempting to minimize both the seek time and the
rotational latency.
The drive uses a command aging feature to prevent the command
reordering algorithm from keeping I/O processes waiting in the
command queue for extended periods of time. The drive allows I/O
processes to wait in the command queue for only a specified length of
time before they are scheduled in the next I/O process.
LED Support
-----------
An LED is installed on the drive:
The LED is turned off as soon as power is applied. If Auto Start is
enabled, the LED is on while the drive is spinning up and turned off
when Auto Start is completed.
The LED is on when a SCSI command is being executed.
The LED flashes when an error prohibits the use of the SCSI
interface.
Hot Plug/Unplug Support
-----------------------
The conditions for hot-plugging drives into an active SCSI bus
follow:
- The drive signal ground must be made before the SCSI bus signals.
- Power-both +5V and +12V-cannot be applied until the SCSI bus
signals are connected.
- The host(s) are not actively trying to access the inserted device.
- The drive is not supplying TERMPWR to the SCSI bus.
- The drive is not supplying termination to the SCSI bus.
The conditions for the removal of a device from an active SCSI bus
follow:
- The host(s) are not actively trying to access the device to be
removed.
- The drive is not supplying TERMPWR to the SCSI bus.
- The drive is not supplying termination to the SCSI bus.
- Power-both +5V and +12V-must be removed before the SCSI bus signals
are disconnected.
- The drive signal ground must be broken after the SCSI bus signals.
The SCA-2 (80-pin) connector allows for proper insertion and
extraction by providing an appropriate mechanical mating that makes
the signal ground connection first upon insertion and last upon
extraction. There are also control signals that allow the proper
application of power to adhere to the insertion and extraction rules
above. However, the user must guarantee that the three rules listed
below apply:
The host(s) are not actively trying to access the inserted device.
The drive is not supplying TERMPWR to the SCSI bus.
The drive is not supplying termination to the SCSI bus.
Physical Characteristics (Option Block)
---------------------------------------
The block consists of a 2-pin by 17-pin male header. Pin-to-pin
spacing is 2 mm by 2 mm.
SCSI Connectors
---------------
Power Connectors and Cables
50-pin Drive Power Connector and Cable
POWER CONNECTOR MATING CONNECTOR WIRE GAUGE
AMP 2-in-1 1x4 PC power connector 18 AWG
68-pin Drive Power Connector and Cable
POWER CONNECTOR MATING CONNECTOR WIRE GAUGE
Molex 3-in-1 combo (or equivalent) 1x4 PC power connector 18 AWG
SCSI Physical Interface
-----------------------
All Western Digital SCSI hard drives are designed to conform to the
SCSI-3 Parallel Interface as described in the draft of proposed ANSI
specification X3T10/855D Revision 15a. In addition, drives equipped
with the 80-pin SCA connector are designed to conform to the Small
Form Factor Committee draft specification SFF-8046 Rev 2.0 entitled
"SCA-2 (Single Connector Attach) for SCSI Disk Drives." Since
tutorials on SCSI-3 and SCA are beyond the scope of this manual,
users should review their SCSI implementations as required to ensure
compliance. The SCSI-3 specification has several informative annex
sections on cabling, bus termination, crosstalk, etc., that are quite
helpful to SCSI system architects and implementors.
DC Power Connector
------------------
Signal Name Pin Number Signal Name
+12V (+12 SUPPLY) 51 52 GROUND (+12 RETURN)
GROUND (+5 RETURN) 53 54 +5V (+5 SUPPLY)
Installation and Maintenance
----------------------------
For instructions on installing the drive, including drive handling
and mounting, determining the configuration, setting the drive
jumpers, and cabling procedures, refer to the WD Enterprise
Installation Guide (document number 4079-001057).
Electrostatic Discharge (ESD) Protection
----------------------------------------
To prevent drive damage, it is essential to keep the drive in an ESD
safe environment. You can take several precautions to avoid permanent
damage to the drive.
- Keep the drive in the shielded anti-static bag prior to testing or
installation.
- Gently place the drive on a padded, grounded anti-static surface
when it is not in its shipping container.
- Wear a grounded wrist strap throughout all phases of drive
handling.
- Do not allow clothing to come in direct contact with the drive or
PCBA.
- Do not insert any other items in the shielded anti-static bag with
the drive.
External Air Filter
-------------------
In addition, adequate clearance above this region must be maintained
to allow the free exchange of air. This region contains the external
air filter, which allows the pressure inside the drive to equalize
with the ambient atmosphere. If obstructed, the filter may not be
able to compensate for expansion and contraction of the air inside
the drive, which may degrade drive performance.
Maintaining the Drive
---------------------
To keep the drive in optimal working order and prolong the life of
the unit, do the following:
- Do not attempt to open the sealed compartment of the WDE9100 drive;
this will void the warranty.
- Avoid harsh shocks or vibrations.
- Observe the environmental limits specified for this product.
- To protect your data, back it up regularly. Western Digital assumes
no responsibility for loss of data. For information about back-up
and restore procedures, consult your operating system manual. There
are a number of utility programs to back up your data.
Caution: Do not remove any product identification labels.
The drive requires no preventive maintenance and contains no
user-serviceable parts. Service and repair of the drive must be
performed at a Western Digital Service Center. Contact your Western
Digital representative for warranty information and service/return
procedures.
**********************************************************************
F E A T U R E S
**********************************************************************
WESTERN WDE9100 INSTALLATION GUIDE 4079-001055 REV. B 10/97
General Description
-------------------
Western Digital, the recognized leader in time to volume hard drive
manufacturing, is first to offer a low-profile 9.1 GB high-
performance SCSI hard drive. Our team of expert enterprise
storage engineers developed this leading-edge drive using Western
Digital's proven technology and world-class quality processes.
The WD Enterprise WDE9100 - the second in a family of low-profile
7200 RPM drives - delivers outstanding performance, capacity, and
reliability, and is an excellent choice for workstation, server,
multi-user, data warehousing, audio-video, and array/RAID
applications.
The drive features a formatted capacity of 9.1 GB in a low-profile
form factor with Ultra SCSI host data transfer rates up to 40 MB/s.
This device also supports high performance I/O features such as
adaptive caching, command queuing, command reordering, active
termination, S.M.A.R.T. (Self Monitoring, Analysis, and Reporting
Technology), and SCAM (SCSI Configure AutoMagically) that allow for
multi-threaded I/O and more intelligent drive reporting. This drive
supports 50-pin, 68-pin, and 80-pin (SCA-2) connectors. In addition,
advanced data protection capabilities such as thermal asperity
detection and correction in hardware make this hard drive ideal for
the mission critical enterprise computing environment.
The WD Enterprise WDE9100 delivers the performance, capacity, and
reliability demanded by all high-performance enterprise systems.
Advanced Features
-----------------
Product Features
- Formatted Capacity of 9.1 GB
- 3.5-Inch Low Profile (1-inch high)
- Magnetoresistive Heads
- 7200 RPM Spindle Speed
- SCSI-3 SPI Compliant; Ultra Fast/Ultra Fast Wide with SCA-2
interface supported
- 512 kilobytes Programmable Multi-segmented Data Buffer (1 MB
option)
- Zoned Recording
- Headerless Format
- SCAM Plug-N-Play Compliant
- Single-ended SCSI Drivers/Receivers
- Active Termination (available on 50- and 68-pin single-ended
drives)
- Downloadable SCSI and Servo Firmware
- Ultra SCSI Interface Supported for up to 40 MB/s Host Transfer
Rates
- Embedded Servo
- Balanced Spindle
- Dynamic Spindle Brake
- Vertical or Horizontal Mounting
Performance Features
--------------------
- Serpentine Seek Technology
- Media Data Rate Up to 160 Mbits/s (20MB/s)
- Average Read Seek Time of < 8 ms
- 4.17 ms Rotational Latency
- Tagged Command Queuing
- Seek and Rotational Command Reordering
- Write/Read Coalescing
- Adaptive Caching
- Self-Optimizing Buffer Ratios
- Adaptive Segmented Cache
- Auto-Read Reallocation/Auto-Write Reallocation (ARRE/AWRE)
- Adaptive Servo Functions
NOTE 50-pin and 68-pin drives can be ordered with or without
terminators.
Reliability Features
--------------------
- Self Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.)
- Thermal Asperity Detection and Correction in Hardware
- E-coat Base Casting
- Hardware On-The-Fly Error Correction
- CRC Data Buffer Protection
- Sector Slipping Defect Management
- Self Diagnostics on Power Up
- 1,000,000 Hour MTBF POH
Options
-------
The following options are incorporated at the time of production, or
shipped separately upon request.
- Data buffer of 1 megabyte
The standard data buffer size is 512 kilobytes. You may order a 1
megabyte option.
- Single-unit shipping pack kit
The drive is shipped in bulk packaging to provide maximum
protection against damage during transit. Units shipped
individually require additional protection as provided by the
single-unit shipping pack. Contact your local Western Digital
sales office for ordering information.
Termination Power
-----------------
50-pin and 68-pin drives have the ability to supply termination power
to the SCSI bus. This option can be enabled by setting the
corresponding jumper on the option block.
Bring-Up Sequence
-----------------
After power is applied, the following events occur as the drive
becomes ready for use.
1. The microprocessor tests itself, the on-board memory, and
components on the printed circuit board assembly (PCBA).
2. The SCSI interface is enabled to accept the following commands:
Inquiry, Request Sense, Start/Stop Unit, Test Unit Ready. Refer to
the Western Digital SCSI Implementation Guide (document number
4096-001343) for additional SCSI commands and features.
3. Internal electronic component initialization and testing
continues.
4. If the Auto Start option is enabled, the motor spins up.
5. The servo system calibrates itself.
6. Additional configuration information is read from an area on the
disk that is reserved for the drive's internal use.
7. A self test is performed on the read/write path.
8. The drive is ready to read and write data.
If an error occurs during the bring-up sequence, sense data is
available if the SCSI interface is working; otherwise the LED
flashes.
If a reassign was in progress when the drive was turned off, the
drive automatically completes that operation during startup.
Regulatory Agency Information
-----------------------------
The drive has met the following regulatory agency standards:
Underwriters Laboratories
UL-Standard 1950, Standard for Safety of Information Technology
Equipment including Electrical Business Equipment
File Number E101559
Federal Communication Commission
Verified to comply with FCC Rules for Radiated and Conducted
Emission, Part 15, Subpart B, for Class B Equipment
Canadian Standards Association
CSA-Standard C22.2, No. 950 - M89, Standard for Safety of Information
Technology Equipment including Electrical Business Equipment
File Number LR 68850
TUV Essen Laboratories
IEC 950 (EN 60 950) Standard for Safety of Information Technology
Equipment including Electrical Business Equipment
CE Compliance for Europe
Verified to comply with EN 55022 for RF Emissions and EN 50082-1 for
Generic Immunity as applicable.
Advanced product features
-------------------------
Compatibility Testing
Western Digital performs extensive testing in its Functional
Integrity Test Lab (FIT Lab). By equipping the FIT Lab with
multiple host systems, adapters, operating systems, and application
programs, compatibility is achieved with a broad range of
applications implemented on workstations, servers, multi-user, and
array systems.
SCSI-3 SPI Compliant
--------------------
The WDE9100 conforms to the SCSI-3 SPI (SCSI Parallel Interface)
standard. The drive also supports the Ultra SCSI performance
specification and is offered in several configurations such as Ultra
Fast (8-bit, 50-pin; up to 20MB/s) and Ultra Fast Wide (16-bit,
68-pin, 80-pin SCA-2; up to 40MB/s) host transfer rates.
Embedded Servo Control
----------------------
The WDE9100 features embedded servo technology to generate accurate
positioning information on every track. An embedded servo system has
servo bursts interspersed with customer data on every track. This
provides a tight coupling between head positioning and user data. In
addition, embedded servo technology is less susceptible to thermal
shifts of the system since customer data and position information are
recorded together on the same track.
Media Defect Management
-----------------------
Western Digital drives support a defect management algorithm that
uses sector slipping. Defective sites are pushed down during a
reassignment operation to maintain a sequential order. Spare sectors
are placed throughout the drive to support this algorithm. This
routine can be invoked by the drive when Auto-Read Reallocation/
Auto-Write Reallocation (ARRE/AWRE) is enabled in MODE SELECT Page 1.
If ARRE/AWRE functions are disabled, the drive reports the status and
may recommend the host request a reassign.
Microcode Download
------------------
Western Digital drives support downloadable microcode via the SCSI
WRITE BUFFER command. The supported modes include Download Microcode
and Save, as well as Download Microcode with Offsets and Save.
Download Microcode with Offsets is used when the buffer is limited to
the full download and requires smaller partial downloads to complete
the download task.
Reed Solomon ECC On-the-Fly
---------------------------
Error Correction Code (ECC) on-the-fly is a correction technique that
reduces the uncorrectable read error rate in hardware. This provides
a high degree of data integrity with no impact on the drive's
performance.
CRC Data Protection
-------------------
Cyclic Redundancy Check (CRC) data protection is a feature that
enhances data integrity. The WDE9100 uses CRC protection for both the
data buffer path and also for protection against ECC miscorrection.
During a write operation, before a user data block enters the cache
(data buffer), the SCSI controller generates CRC data (2 bytes) and
attaches it to the user data block (usually 512 bytes). In addition,
prior to generating the data ECC bytes, four CRC bytes are then added
to the existing bytes (data bytes and 2 CRC bytes).
During a read operation, after the drive has done its ECC check and
possible correction, the four byte CRC operation takes place. In the
unlikely event a miscorrection results from the ECC operation, the
CRC detects this and the read is repeated. If the CRC check is
successful, the data is put in the drive cache. The two byte CRC
check occurs when the data is being transferred out of the SCSI
controller chip to the host controller. A CRC error at this juncture
results in a check condition to inform the host controller of the
error.
Zoned Recording
---------------
The WDE9100 employs zoned recording to increase data density on the
outer tracks of the drive. Zoned recording allows the adjustment of
the number of sectors per track, which provides storage of more
sectors on the larger, outer tracks. Formatting packs data uniformly
throughout the surface of the platter by dividing the outer tracks
into more sectors. With more bytes per track, the drive reads the
data in the outer zones at a faster rate.
Headerless Format
-----------------
Headerless format is also known as ID-less or No-ID sector format.
This format removes the header (or ID fields) and all the information
within the header (track format) to provide a dramatic increase in
user capacity. Our advanced, integrated SCSI controller assumes the
task of determining the physical location of each sector.
Auto-Read Reallocation/Auto-Write Reallocation (ARRE/AWRE)
----------------------------------------------------------
This error recovery feature controls whether automatic reallocation
takes place during read and write commands. If enabled, the drive may
perform automatic reallocations to correct a potentially defective
sector.
Magnetoresistive (MR) Heads
---------------------------
The WDE9100 incorporates magnetoresistive heads to meet increasing
capacity requirements. The MR head uses separate read and write
elements in order to optimize read and write capabilities. The write
element is a thin-film inductive element that records data. The read
element, composed of a thin-film material whose resistance changes in
the presence of a magnetic field, produces a strong signal, allowing
significant increases in areal densities. When MR heads are used in
combination with a PRML read channel, capacities can be significantly
increased.
Thermal Asperity (TA) Detection and Correction
----------------------------------------------
A thermal asperity (media defect or particulate) can cause a sudden
transfer of energy to an MR head, and the resistance change that
accompanies this activity can limit the drive's ability to read and
write for a period of time. The WDE9100 uses advanced techniques to
detect an increased thermal condition due to an asperity. If a data
error occurs, several recovery algorithms are used to recover the
data in read or write modes.
E-coat Base Casting
-------------------
The WDE9100 base casting has an electro-deposited organic coating,
commonly referred to as E-coat. This smooth coating reduces the
particle count inside the drive housing, which results in a clean
environment for MR heads.
Error Recovery Operations
-------------------------
Error recovery options are set using MODE SELECT Page 1 (Read/Write
Error Recovery Page) and the Write Recovery Threshold and Read
Recovery Threshold fields in MODE SELECT Page 0 (WD Vendor Unique
Page).
The drive employs a variety of recovery actions based on the type of
error that occurs. Separate recovery actions are defined for read
errors, write errors, servo errors, and drive fault errors. For a
given error type, several different recovery actions may be used. For
example, read error recovery may use retries, servo track offsets,
channel parameter modification, and software ECC in an attempt to
recover the error. Error information is available to the host via the
REQUEST SENSE command based on the settings in MODE SELECT Pages 0
and 1.
The drive uses a 3-way interleaved Reed-Solomon ECC operating on 8
bit (1 byte) symbols. On-the-fly ECC is capable of correcting single
burst errors up to 1 byte per interleave (3 bytes total) with no
performance degradation. On-the-fly correction is done in hardware
and cannot be disabled. The drive firmware also implements a software
ECC, which is capable of correcting random errors up to 3 bytes per
interleave (9 bytes total) and burst errors up to 5 bytes per
interleave (15 bytes total). Refer to the Western Digital SCSI
Implementation Guide (document number 4096-001343) for more
information.
Self-Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.)
----------------------------------------------------------------
Self-Monitoring, Analysis and Reporting Technology (S.M.A.R.T.) is a
hard drive firmware technology that performs drive failure prediction
by monitoring selected parameters during normal drive operations. The
intent of this technology is to minimize unscheduled system downtime
caused by predictable failures. By monitoring selected parameters,
the S.M.A.R.T. firmware can predict some drive failures before they
actually occur, allowing the user to schedule drive replacement and
minimize system interruptions.