Notes:
1.The user can arbitrarily specify the following parameters according to the system requirements:
∙ARRE
∙TB
∙PER
2.The user also can arbitrarily specify parameters other than the above. However, it is recommended to use the default setting in normal operations.
(2)Disconnection/reconnection parameters (page code = 2)
The following parameters are used to optimize the start timing of reconnection processing to transfer data on the SCSI bus at a read (READ or READ EXTENDED command) or write operation (WRITE, WRITE EXTENDED, or WRITE AND VERIFY command) of the disk. Refer to Chapter 2 of SCSI Logical Interface Specifications for further details.
a. Disconnection/reconnection parameters (page code = 2)
Parameter |
| Default value |
• Buffer full ratio |
| 20 (HEX) |
• Buffer empty ratio |
| 20 (HEX) |
Notes:
1.In a system without the disconnection function, these parameters need not be specified.
2.Determine the parameter values in consideration of the following performance factors of the system:
∙Time required for reconnection processing
∙Average data transfer rate of the SCSI bus
∙Average amount of processing data specified with a command
Refer to Chapter 2 of SCSI Logical Interface Specifications for how to obtain the rough calculation values for the parameter values to be set. It is recommended to evaluate the validity of the specified values by measuring performance in an operation status under the average system load requirements.
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