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6.2.3Hot plugging Cheetah 15K.5 SCSI disc drives
The ANSI
Case 1 - All bus devices powered off during removal or insertion
Case 2 - RST signal asserted continuously during removal or insertion
Case 3 - Current I/O processes not allowed during insertion or removal
Case 4 - Current I/O process allowed during insertion or removal, except on the device being changed
Seagate Cheetah 15K.5 SCSI disc drives support all four hot plugging cases. Provision shall be made by the system such that a device being inserted makes power and ground connections prior to the connection of any device signal contact to the bus. A device being removed shall maintain power and ground connections after the disconnection of any device signal contact from the bus (see
It is the responsibility of the systems integrator to assure that no hazards from temperature, energy, voltage, or ESD potential are presented during the hot connect/disconnect operation.
All I/O processes for the SCSI device being inserted or removed shall be quiescent. All SCSI devices on the bus shall have receivers that conform to the
If the device being hot plugged uses
The SCSI bus termination and termination power source shall be external to the device being inserted or removed.
End users should not mix devices with high voltage differential (HVD) drivers and receivers and devices with SE, LVD, or multimode drivers and receivers on the same SCSI bus since the common mode voltages in the HVD environment may not be controlled to safe levels for SE and LVD devices (see ANSI
The disc drive spindle must come to a complete stop prior to completely removing the drive from the cabinet chassis. Use of the Stop Spindle command or partial withdrawal of the drive, enough to be disconnected from the power source, prior to removal are methods for insuring that this requirement is met. During drive insertion, care should be taken to avoid exceeding the limits stated in Section 7.4.4, "Shock and vibration" in this manual.
6.2.4S.M.A.R.T.
S.M.A.R.T. is an acronym for
Note. The firmware will monitor specific attributes for degradation over time but cannot predict instanta- neous drive failures.
Each attribute monitors a specific set of conditions in the operating performance of the drive, and the thresh- olds are optimized to minimize “false” predictions.
16 | Cheetah 15K.5 SCSI Product Manual, Rev. J |