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i. Maximum Pre-fetch
This parameter specifies the maximum quantity of logical data blocks pre-fetched to the
data buffer with the READ command or READ EXTENDED command.
The IDD varies the pre-fetch volume according to the volume of data requested by the
READ command or READ EXTENDED command. The value reported to the MODE
SENSE command always indicates the number of blocks corresponding to 1 cache
segment - 1.
This parameter cannot be changed. The IDD disregards the specification in this field.
j. Maximum Pre-fetch Control Block Count
This parameter specifies the maximum quantity of logical data blocks pre-fetched to the
data buffer with the READ command or READ EXTENDED command. In the IDD the
maximum pre-fetch quantity cannot be limited.
This parameter cannot be changed. The IDD disregards the specification in this field.
k. FSW (force sequential write)
"1" : If the IDD writes multiple blocks, this indicates that data are recorded on the disk
media in the order in which they are transferred from the INIT.
"0" : If the IDD writes multiple blocks, this indicates that data are recorded on the disk
media with their order changed in order to complete the command in the fastest
time.
This bit cannot be changed. The IDD disregards the specification in this bit and operates
according to the "Default" value (="1").
l. Cache Segment Count
This parameter specifies the number of cache segments used by the IDD. This parameter
is valid when the SIZE bit specification is "0."
The initiator can specify x01 to x10 in this parameter. When x00 is specified in this
parameter, the IDD performs rounding processing of the parameter. When a value greater
than x10 is specified, the IDD performs rounding processing and sets x10. The default
value of this parameter is "04" (=124K x 4).
This parameter indicates the same value for all initiators and if it is changed by any
initiator, a UNIT ATTENTION condition (UNIT ATTENTION
parameter changed [=2A-01] is generated for all the initiators that did not change it.
C141-E039-01EN
[=6] / Mode select
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