Seagate ST3300056SS (FDE) ユーザーズマニュアル

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Cheetah 15K.6 SAS Product Manual, Rev. B

A seek error is defined as a failure of the drive to position the heads to the addressed track. After detecting an 
initial seek error, the drive automatically performs an error recovery process. If the error recovery process fails, 
a seek positioning error (Error code = 15h or 02h) will be reported with a Hardware error (04h) in the Sense 
Key.   Recoverable seek errors are specified at Less than 10 errors in 10

8

 seeks.   Unrecoverable seek errors 

(Sense Key = 04h) are classified as drive failures.

An interface error is defined as a failure of the receiver on a port to recover the data as transmitted by the 
device port connected to the receiver. The error may be detected as a running disparity error, illegal code, loss 
of word sync, or CRC error. 

You can enhance the reliability of Cheetah disk drives by ensuring that the drive receives adequate cooling. 
Section 6.0 provides temperature measurements and other information that may be used to enhance the ser-
vice life of the drive. Section 8.2 provides recommended air-flow information.

These drives shall achieve an AFR of 0.55% (MTBF of 1,600,000 hours) when operated in an environment that 
ensures the HDA case temperatures do not exceed the values specified in Section 6.4.

Operation at case temperatures outside the specifications in Section 6.4 may increase the AFR (decrease the 
MTBF). AFR and MTBF statistics are population statistics that are not relevant to individual units.

AFR and MTBF specifications are based on the following assumptions for Enterprise Storage System environ-
ments:

• 8,760 power-on hours per year.
• 250 average on/off cycles per year.
• Operations at nominal voltages.
• Systems will provide adequate cooling to ensure the case temperatures specified in Section 6.4.1 are not 

exceeded.

No routine scheduled preventive maintenance is required.

When a disk is powered on by switching the power or hot plugged, the drive runs a self test before attempting 
to communicate on its’ interfaces. When the self test completes successfully, the drive initiates a Link Reset 
starting with OOB. An attached device should respond to the link reset. If the link reset attempt fails, or any 
time the drive looses sync, the drive initiated link reset. The drive will initiate link reset once per second but 
alternates between port A and B. Therefore each port will attempt a link reset once per 2 seconds assuming 
both ports are out of sync..

If the self-test fails, the does not respond to link reset on the failing port.

It is the responsibility of the systems integrator to assure that no temperature, energy, voltage haz-
ard, or ESD potential hazard is presented during the hot connect/disconnect operation. Discharge 
the static electricity from the drive carrier prior to inserting it into the system.

The drive motor must come to a complete stop prior to changing the plane of operation. This time is 
required to insure data integrity.