An AIX system， which is running a database， is having performance issues with I/O writing.  The DBA has provided numbers for the HIGH and LOW watermarks for pending file writes， which will optimize the system for best performance.  To set these numbers， which of the following commands would be used？（）

单项选择题Inordertoensurebestreadperformance，whichofthefollowingindicateshowlargeanapplication’sreadbuffersizeshouldbeifthefilesystemtobereadisstripedacrossNdisksusingLVMstriping？（）

A. N times the stripe unit size
B. N times the VMM minfree parameter
C. The same value as that of the VMM maxfree parameter
D. The same value as that of  the VMM maxrndwrt parameter

单项选择题ATCP IPapplicationreceivesfilesfromaremotemachine.Theapplicationreads32kilobytesofdataatatimetothesocket，buthasnotissuedasystemcalltosetthewindowsize.Whichofthefollowingproceduresshouldbeperformedonthepersonalmachinetoincreasethethroughputoftheapplication？（）

A. Increase the size of thewall
B. Increase the size of sb_max
C. Increase the size of tcp_recvspace
D. Increase the size of tcp_sendspace

单项选择题Whichofthefollowingcommandsshouldbeusedtodeterminewhetheralogicalvolumeiscontiguousacrossadisk？（）

A. lslv
B. lsfs
C. lspv
D. fileplace

单项选择题Thermsscommandprovidesthefacilitytorunanapplicationoverarangeofmemorysizesanddisplaytheperformancestatistics.Howisthesimulatedmemoryresettotherealmemoryofthemachine？（）

A. rmss -c
B. rmss -p
C. rmss -r
D. rmss -s

单项选择题Thesystemadministratorhasbeengettingcomplaintsaboutslowperformancefromtheserver.Afterrunningvmstattheadministratornoticesaveragereadingsthatshowthefreelist（fre）approachingzero，aswellaspage-in（pi）andpage-out（po）valuestobehigh.Furthermore，theapplicationsrunningareessentialtodailybusinessoperations.Whichofthefollowingrecommendationswouldprovidethebestoverallimprovement？（）

A. Increase physical disk
B. Increase number of CPU’s
C. Increase physical memory
D. Increase number of servers