Fujitsu MBA3147RC - Enterprise 147 GB Hard Drive Product Manual page 67

5.4 Checking Operation after Installation and Preparing the HDDs for Use
(2) Caching parameters (page code = 8)
The following parameters are used to optimize HDD Read-Ahead caching operations under the
system environments. Refer to Chapter 3 "Data Buffer Management" of the SAS INTERFACE
MANUAL for further details.
• IC:
• RCD:
• WCE:
• MF:
• DISC:
• DISABLE PRE-FETCH TRANSFER LENGTH
• MINIMUM PRE-FETCH
• MAXIMUM PRE-FETCH
• MAXIMUM PRE-FETCH CEILING
• NUMBER OF CACHE SEGMENTS
Notes:
1. When Read-Ahead caching operations are disabled by the caching parameter, these
parameter settings have no meaning except write cache feature.
2. Determine the parameters in consideration of how the system accesses the disk. When the
access form is not determined uniquely because of the processing method, the parameters
can be re-set actively.
3. For sequential access, the effective access rate can be increased by enabling Read-Ahead
caching operations and Write Cache feature.
(3) Control mode parameters (page code = A)
The following parameters are used to control the tagged queuing and error logging.
a. Control mode parameters
• QUEUE ALGORITHM MODIFIER
• QErr:
C141-E252
Parameter
Initiator control
Disabling Read-Ahead caching operations
Write Cache Enable
Specifying the multipliers of "MINIMUM
PRE-FETCH" and "MAXIMUM PRE-
FETCH" parameters
Prefetch operation after track switching during
prefetching
Parameter
Resume or abort remaining suspended
commands after sense pending state
Default value
0 (HDD-specific
control (page
cache))
0 (enabled)
1 (enabled)
0 (Specifying
absolute value)
1 (enabled)
X'FFFF'
X'0000'
X'0000'
X'FFFF'
X'08'
Default value
0 (Execution sequence of
read/write commands is
optimized.)
0 (command is resumed)
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