8 error rate, 9 media defects, 10 load/unload function – FUJITSU MHV2060BH User Manual

Page 35

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1.8 Error Rate

C141-E224

1-11

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 10

14

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 10

7

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 the commands listed below are
executed.

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.)

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