Fujitsu MBB2073RC, MBB2147RC manual Disc, Disable PRE-FETCH Transfer Length Xffff Minimum PRE-FETCH

5.4Checking 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.

	Parameter	Default value
• IC:	Initiator control	0 (HDD-specific
		control (page
		cache))
• RCD:	Disabling Read-Ahead caching operations	0 (enabled)
• WCE:	Write Cache Enable	1 (enabled)
• MF:	Specifying the multipliers of "MINIMUM	0 (Specifying
	PRE-FETCH" and "MAXIMUM PRE-FETCH"	absolute value)
	parameters
• DISC:	Prefetch operation after track switching during	1 (enabled)
	prefetching
• DISABLE PRE-FETCH TRANSFER LENGTH		X'FFFF'
• MINIMUM PRE-FETCH		X'0000'
• MAXIMUM PRE-FETCH		X'0000'
• MAXIMUM PRE-FETCH CEILING		X'FFFF'
• NUMBER OF CACHE SEGMENTS		X'08'

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

	Parameter	Default value
• QUEUE ALGORITHM MODIFIER		0 (Execution sequence of
		read/write commands is
		optimized.)
• QErr:	Resume or abort remaining suspended	0 (command is resumed)
	commands after sense pending state

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