Hitachi HUS151414VL3600, Specifications

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Hitachi Ultrastar 15K147 SCSI Hard Disk Drive Specification
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20.20.4.14 Miscompare Recovery
A miscompare can occur on a Verify (2F) command or a Write and Verify (2E) with the byte check (BytChk) bit active. Recovery for a mis-
compare error is different for the two commands.
Verify Command
The initiator should do the following:
1. Verify that the data sent to the drive is the correct data for the byte-by-byte compare.
2. Read the data from the media with a Read (08) or Read (28) command and verify that the data from the media is the expected data for
the byte-by-byte compare.
- If all data are correct, this is an indication that the data may have been read from the media incorrectly without an error detected.
Service the drive using the procedure specified in Section 20.20.1, “Drive Service Strategy” on page 252.
- If all data are not correct, this is an indication that the data on the media is not the data the initiator expected. Rewrite the correct
data to the media.
Write and Verify Command
The drive uses the same data in the data buffer to write then read and compare. A miscompare error on the Write and Verify (2E) command is
an indication that the drive cannot reliably write or read the media. Service the drive using the procedures specified in Section 20.20.1,
“Drive Service Strategy” on page 252.
20.20.4.15 Microcode Error
The microcode from the interface is validated before the device operates using that microcode. When the validation detects incorrect or
incomplete data, the Drive enters degraded mode.
If the initiator attempted to load microcode using the Write Buffer (3B) retry the Write Buffer (3B). If the command completes with
• Good Status - return to normal processing
• Check Condition Status - service the drive using the service guidelines recommended in Section 20.20.1, “Drive Service Strategy”
on page 252.
If the check sum error occurred during normal processing, the initiator may attempt to load microcode before deciding to service the drive
using the service guidelines recommended in Section 20.20.1, “Drive Service Strategy” on page 252.
To load new microcode, the initiator should issue a Write Buffer (3B) command with the download and save option. If the Write Buffer (3B)
command completes with
• Good Status, return to normal processing. Retry the failing command. If the task complete with
- Good Status - Continue normal processing.
- Check Condition Status for check sum error - Service the drive using the service guidelines recommended in Section 20.20.1,
“Drive Service Strategy” on page 252.
- Check Condition Status for any other error - follow the recommended recovery procedure for the error reported.
• Check Condition Status for Check sum error, service the drive using the service guidelines recommended in Section 20.20.1,
“Drive Service Strategy” on page 252.
• Check Condition Status for any other error, follow the recommendations for the returned sense data.
20.20.4.16 Predictive Failure Analysis
The Drive performs error log analysis and will alert the initiator of a potential failure. The initiator should determine if this
device is the only device with error activity.
If this drive is the only drive attached to the initiator with error activity, service the drive using the procedures specified in Sec-
tion 20.20.1, “Drive Service Strategy” on page 252.
Note: Service for this drive can be deferred. The longer service is deferred, the more probable a failure can occur that will
require immediate service.
If more than this drive is experiencing error activity, the drive is probably not at fault. Locate and service the outside source
causing error activity on this drive.