Fujitsu MAY2036RC, MAY2073RC manual Disc, Xffff, Xxxx

5.4Checking Operation after Installation and Preparing the HDDs for Use

(2)Caching parameters

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 Serial Attached SCSI Interface Specifications for further details.

	Parameter	Default value
• IC:	Initiator control	0 (Drive-specific
		control (page
		cache))
• RCD:	Disabling Read-Ahead caching operations	0 (enabled)
• WCE:	Write Cache Enable	1 (enabled)
• MS:	Specifying the multipliers of "minimum	0 (Specifying
	prefetch" and "maximum prefetch" parameters	absolute value)
• DISC:	Prefetch operation after track switching during	1 (enabled)
	prefetching
• Number of blocks for which prefetch is suppressed		X'FFFF'
• Minimum prefetch		X'0000'
• Maximum prefetch		X' XXXX'
		(1 cache segment)
• Number of blocks with maximum prefetch restrictions		X'FFFF'
• Number of 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

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

C141-E230 5-9