fio基础19

replay_no_stall=intWhenreplayingI/Owithread_iologthedefaultbehavioristoattempttorespectthetimestampswithinthelogandreplaythemwiththeappropriatedelaybetweenIOPS.Bysettingthisvariablefiowillnotrespectthetimestampsandattempttoreplaythemasfastaspossiblewhilestillrespectingordering.TheresultisthesameI/Opatterntoagivendevice,butdifferenttimings.replay_redirect=strWhilereplayingI/Opatternsusingread_iologthedefaultbehavioristoreplaytheIOPSontothemajor/minordevicethateachIOPwasrecordedfrom.Thisissometimesundesirablebecauseonadifferentmachinethosemajor/minornumberscanmaptoadifferentdevice.Changinghardwareonthesamesystemcanalsoresultinadifferentmajor/minormapping.Replay_redirectcausesallIOPStobereplayedontothesinglespecifieddeviceregardlessofthedeviceitwasrecordedfrom.i.e.replay_redirect=/dev/sdcwouldcauseallIOintheblktracetobereplayedonto/dev/sdc.Thismeansmultipledeviceswillbereplayedontoasingle,ifthetracecontainsmultipledevices.Ifyouwantmultipledevicestobereplayedconcurrentlytomultipleredirecteddevicesyoumustblkparseyourtraceintoseparatetracesandreplaythemwithindependentfioinvocations.Unfortuantelythisalsobreaksthestricttimeorderingbetweenmultipledeviceaccesses.replay_align=intForcealignmentofIOoffsetsandlengthsinatracetothispowerof2value.replay_scale=intScalesectoroffsetsdownbythisfactorwhenreplayingtraces.per_job_logs=boolIfset,thisgeneratesbw/clat/iopslogwithperfileprivatefilenames.Ifnotset,jobswithidenticalnameswillsharethelogfilename.Default:true.write_bw_log=strIfgiven,writeabandwidthlogofthejobsinthisjobfile.Canbeusedtostoredataofthebandwidthofthejobsintheirlifetime.Theincludedfio_generate_plotsscriptusesgnuplottoturnthesetextfilesintonicegraphs.Seewrite_lat_logforbehaviourofgivenfilename.Forthisoption,thesuffixis_bw.x.log,wherexistheindexofthejob(1..N,whereNisthenumberofjobs).If'per_job_logs'isfalse,thenthefilenamewillnotincludethejobindex.write_lat_log=strSameaswrite_bw_log,exceptthatthisoptionstoresiosubmission,completion,andtotallatenciesinstead.Ifnofilenameisgivenwiththisoption,thedefaultfilenameof"jobname_type.log"isused.Evenifthefilenameisgiven,fiowillstillappendthetypeoflog.Soifonespecifieswrite_lat_log=fooTheactuallognameswillbefoo_slat.x.log,foo_clat.x.log,andfoo_lat.x.log,wherexistheindexofthejob(1..N,whereNisthenumberofjobs).Thishelpsfio_generate_plotfinethelogsautomatically.If'per_job_logs'isfalse,thenthefilenamewillnotincludethejobindex.write_iops_log=strSameaswrite_bw_log,butwritesIOPS.Ifnofilenameisgivenwiththisoption,thedefaultfilenameof"jobname_type.x.log"isused,wherexistheindexofthejob(1..N,whereNisthenumberofjobs).Evenifthefilenameisgiven,fiowillstillappendthetypeoflog.If'per_job_logs'isfalse,thenthefilenamewillnotincludethejobindex.log_avg_msec=intBydefault,fiowillloganentryintheiops,latency,orbwlogforeveryIOthatcompletes.Whenwritingtothedisklog,thatcanquicklygrowtoaverylargesize.Settingthisoptionmakesfioaveragetheeachlogentryoverthespecifiedperiodoftime,reducingtheresolutionofthelog.Defaultsto0.log_offset=intIfthisisset,theiologoptionswillincludethebyteoffsetfortheIOentryaswellastheotherdatavalues.