Fujitsu MHW2040AC manual Error Rate, Media Defects, Load/Unload Function, Unrecoverable read error

1.8 Error Rate

abnormalities during disk media initialization (formatting) or processing of defects (alternative block assignment).

1.8 Error Rate

Known defects, for which alternative blocks can be assigned, are not included in the error rate count below. It is assumed that the data blocks to be accessed are evenly distributed on the disk media.

(1) Unrecoverable read error

Read errors that cannot be recovered by maximum read retries of drive without user’s retry and ECC corrections shall occur no more than 10 times when reading data of 1014 bits. Read retries are executed according to the disk drive’s error recovery procedure, and include read retries accompanying head offset operations.

(2) Positioning error

Positioning (seek) errors that can be recovered by one retry shall occur no more than 10 times in 107 seek operations.

1.9 Media Defects

Defective sectors are replaced with alternates when the disk drive is formatted prior to shipment from the factory (low level format). Thus, the hosts see a defect- free device.

Alternate sectors are automatically accessed by the disk drive. The user need not be concerned with access to alternate sectors.

1.10 Load/Unload Function

The Load/Unload function is a mechanism that loads the head on the disk and unloads the head from the disk.

The product supports a minimum of 600,000 Load/Unload cycles.

Unload is a normal head unloading operation and is executed by the operations below:

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Hard Reset

STANDBY command issued

STANDBY IMMEDIATE command issued

SLEEP command issued

IDLE IMMEDIATE command (with unload feature) issued

Power Mode shifted with APM/APS feature

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