IBM Ultrastar 36LZX, Технические характеристики

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LED Mode is designed to control the operation of a drive LED driver.
- LED Mode = 0000b
The CMDAC bit controls the LED.
CMDAC = 1 (Command Active)
CMDAC = 0 (Motor Active)
- LED Mode = 0001b (Motor Active)
When the motor is spinning, the LED is high.
- LED Mode = 0010b (Command Active).
When there is a command active or in the queue, the LED is high.
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Temperature Threshold specifies the threshold value in degrees Celsius for the thermal sensor
warning message. A value of 0 selects the default value (85 degrees Celsius).
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Command Aging Limit This value is used to control the maximum time a command should wait in
the command queue when the CAEN bit is set. Each unit of this timer is 50 ms.
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QPE Read Threshold specifies the error reporting threshold for read operations when the QPE bit is
set to one.
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QPE Write Threshold specifies the error reporting threshold for write operations when the QPE bit
is set to one.
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DRRT (Disable Restore Reassign Target) bit disables the reading and restoration of the target LBA
during a Reassign Blocks command. If the DRRT bit is zero, the reassign command attempts to re-
store the target LBA's data. If the data cannot be restored, the target LBA is reassigned and written
with a data pattern of all 00's. If the DRRT bit is one, no attempt is made to restore the target LBA.
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FFMT (Fast Format enable) bit allows the formatting of the drive without any writes to the customer
media. All format operations are allowed including changing block sizes and manipulating defects.
The drive will operate normally after a fast format with the following caveat: since no data is written
to any customer data blocks as a result of a Fast Format operation, there is a possibility that a read
attempt to any particular block (without having previously written to that block) will result in an
unrecoverable data error. This will most likely happen if the block size is changed as every LBA will
contain data of an incorrect length and apparently an incorrect starting point. It is also possible to
generate an uncorrectable data error without changing block sizes if the defect list is shortened and
previously bad blocks become visible in the customer address space. Of course ALL DATA ON THE
DRIVE WILL BE LOST as the result of any format operation and so any attempt to read blocks which
have not been written to will result in unpredictable behavior.
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FCERT (Format Certification) bit determines whether the certification step will be performed during a
Format Unit command. A FCERT bit set to 0 disables certification. A FCERT bit set to 1 enables the
certification step.
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IRT (Integration Reassign Threshold) bit determines the threshold used to recommend reassignment
or initiate auto-reassign. When IRT is disabled with a value set to 0, the thresholds used to deter-
mine when a sector should be reassigned and either recommended or auto-reassigned are set to
values optimized for end user environments, depending upon state of the ARRE and AWRE bits.
When enabled by setting to 1, thresholds optimized for integrating the drive into a system to mini-
mize end- user field failures is used.
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IVR (Integration Verify Recovery) bit determines the maximum number of steps attempted during a
Verify Recovery Procedure (VRP). When disabled with a value set to 0, all of the steps are
attempted, if required. When enabled by setting to 1, a maximum number of steps optimized for
integrating the drive into a system to minimize end-user field failures is used.
Ultrastar 36LZX hard disk drive specifications
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