(4)Data assurance in the event of power failure
Except for the data block being written to, the data on the disk media is assured in the event of any power supply abnormalities. This does not include power supply abnormalities during disk media initialization (formatting) or processing of defects (alternative block assignment).
1.8Error 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 126 times read retries without user's retry and ECC corrections shall occur no more than 10 times when reading data of 1015 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.
1.9Media Defects
Defective sectors are replaced with alternates when the disk is formatted prior to shipment from the factory (low level format). Thus, the host sees a
Alternate sectors are automatically accessed by the disk drive. The user need not be concerned with access to alternate sectors.
Chapter 6 describes the low level format at shipping.
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