3 host diagnostics, 4 log sense, 13 error recovery – Maxtor 10K V User Manual

Page 221: 1 seek error recovery, 2 data read errors, 3 reallocation of bad blocks

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Maxtor Atlas 10K V

6-7

6.12.3

Host Diagnostics

The Host Processor can command the drive to perform diagnostic tests and report
status using RECEIVE and SEND DIAGNOSTIC RESULTS commands. Certain
parameters can be sent to the drive to alter or enhance the performance of the
diagnostic tests specified.

6.12.4

Log Sense

Maxtor implements multiple LOG SENSE pages which logically group together
parameters related to disk and subsystem activities. Monitoring this data enables users
to observe drive performance and possibly predict failures.

6.13

ERROR RECOVERY

The mode pages control all error recovery. Any error recovery that is enabled is
attempted without host intervention.

6.13.1

Seek Error Recovery

Seek error recovery is automatic if the hardware is physically able to position to the
correct track.

6.13.2

Data Read Errors

Data read errors are recovered, if possible, by one or more of the following methods:

• Correction of the data “on-the-fly” with ECC hardware.

• Re-try the operation.

• Reload read channel registers to calibrated values.

• Off-track Recovery. Use different off-track offsets and re-try.

• Use a fixed gain while retrying.

• Margin servo thresholds to facilitate seek and detent.

• Margin the error tolerance of sync mark detection.

• Force sync mark detection while retrying.

• Skip Sector Rereads. Retries, each without one of eight earlier servo

blocks.

• Correction of the bad data with the software ECC algorithm.

• Switching the bias current of the MR head between retries.

• TA baseline compensation, and other TA recovery methods.

6.13.3

Reallocation of Bad Blocks

Most of the spare blocks are located on the inner cylinders of the drive. All defective
blocks are in-line spared at the factory or at format time. Some spare blocks are

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