1.8 Error Rate
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
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 the commands listed below are executed.
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STANDBY command issued
STANDBY IMMEDIATE command issued
SLEEP command issued
IDLE command issued
SLUMBER signal transferred
(PMREQ_S signal is transferred from the host or the drive, and the host responds with PMACK signal.)
