Error Rate; Media Defects - Fujitsu MPD3XXXAT Product Manual

(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).
1.8

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 read retries without user's retry and ECC corrections
shall occur no more than 10 times when reading data of 10
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
7
in 10 seek operations.
1.9

Media 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 defect-free device.
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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bits. Read retries are executed