Linux操作系统11-优化.ppt

AcegeneITCo.Ltd.,1,Linux操作系统系统优化,AcegeneITCo.Ltd.,2,内容提要,Performanceconceptsandmeasurementtools:CPUMemoryDiskI/ONetworkProcessProfilingKernel&Applications,MeasurementTools,LinuxhasmeasurementtoolscommontoUNIXplatforms:SystemActivityReporter:sarHistoricaldatabaseVirtualMemoryStatistics:vmstat,freeI/OStatistics:iostatTopResourceConsumers:top-cX-basedtools:xosview,gnome-system-monitor,ksysguard,gkrellm,CPUMeasurements,IdentifytheCPUstatisticsandinterpretthem:Idletime:%idleExecutingusercode:%userExecutingsystemcode:%systemLoadaverage:runq-szStartwithcat/proc/cpuinfoTotalCPUcount/speedThereareseveralwaystoseethesameinformation,forexample:CPUactivity,CPUActivity-mpstat,#mpstat-P,#mpstat-PALL11Linux2.4.21-15.EL(raclinux1)08/04/2004CPU%user%nice%system%idleintr/sall19.500.0031.5049.00111.00027.000.0042.0031.00111.00112.000.0021.0067.00111.00,WhatismyCPUdoing?:mpstat,CPUActivity-sar,#sar-u23Linux2.4.21-15.EL(raclinux1)08/04/200402:02:34AMCPU%user%nice%system%idle02:02:36AMall1.140.001.7197.1402:02:38AMall2.620.003.6693.7202:02:40AMall0.540.003.7895.68Average:all1.450.003.0995.46,#sar-u,WhatismyCPUdoing?:sar,CPUActivity-iostat,#iostat-c23Linux2.4.21-15.EL(raclinux1)08/04/2004avg-cpu:%user%nice%sys%idle5.730.0017.1677.11avg-cpu:%user%nice%sys%idle4.620.0027.1868.21avg-cpu:%user%nice%sys%idle9.550.0035.9654.49,#iostat-c,WhatismyCPUdoing?:iostat,LinuxVirtualMemory,EachprocessisassignedacontiguousaddressspaceinvirtualmemorythatmapsprocessmemoryallocationstotherealmemoryUseraddressspaceisacontiguoussetofpagesandislimitedto4GBperprocessPhysicalAddressExtension(PAE),allowsaccesstomorethan4GBofphysicalmemoryRHat:enterprisekernel(impliedSMP)SuSE:64GBkernel(impliedSMP),Swap,Swapspace(disk),Physicalmemory(RAM),Virtualmemory,Swapped-inpages,Swapped-outpages,MeasuringSwap,Howmuchisavailable/used?swapon-s(cat/proc/swaps)vmstatso:AmountofmemoryKB/sSWAPOUTtodisksi:AmountofmemoryKB/sSWAPINfromdiskswapd:AmountofvirtualmemoryKBreservedCreate/Addmore?#mkswap/dev/sdc3fstab:/dev/sdc3swapswappri=4200,MemoryUsage,Kernel(notpaged),Sharedmemory,Processmemory,Processmemory,Processmemory,Pagecache,Buffercache,Kernelmodules,Dynamicallyadjusted,Paged,Paged/locked,Notpaged,Measurememoryutilizationandpaging.Identifythesignificantmemorystatistics.cat/proc/meminfo(unitsKB)MemTotal:TotalphysicalmemoryMemFree:TotalfreememoryLowFree:Freememorybelow1GBphysicalBuffers:LinuxBufferCacheCached:LinuxPageCacheBigFree:Freebigpagesmemory,MeasuringMemoryUsage,NoFreeMemory?,freecommandreportsaverylownumber,shouldIbeworriedItsOKifLinuxbufferorpagecachearebigLookin-/+buffer/cacherowoffreeforprojectedfreememoryVeryusefulstat,Memory-sar,-Bpagingstatistics-Rmemorystatistics-Wswappingstatistics,#sar-B#sar-R,AcegeneITCo.Ltd.,15,MeasuringDiskI/O,YoushouldmonitortheI/Oacrossalldevicesandlookforslowdevicesusing:sar,iostat,vmstatArchivecollectedstatisticsforcomparison,AcegeneITCo.Ltd.,16,NetworkTraffic,Checkthefollowingsourcesofnetworktraffic:OracleSQL*NetServicingSQLconnectionsInterconnectinRACenvironmentNetworkfilesystemSambaHTTPserverStartwithsar-nDEViptrafalsoveryuseful,sarFlags,-freadfromsarhistoricalfile/var/log/sa/-s-estart/endtimes-shh:mm:ss-rmemory/swaputilization-cprocesscreationactivity-wcontextswitchingactivity,AcegeneITCo.Ltd.,18,ProcessSpecific,Specificprocessisasuspect:Systemcalltrace:stracepLibrarycalltrace:ltracepDetailedprocessstatistics:psoTry:ps-e-opid,ppid,pcpu,rss,vsz,pri,wchan,cmdWhohasmyfileopen?lsof-ppidForProcessTree,usepstreepNotseeingaprocess,itsprobablyathread,try:ps-efm,AcegeneITCo.Ltd.,19,WhatDoestheKernelDo?,Itspossibletoprofilethekernelandidentifywhereitsspendingtime:Bootwith“profile=2nmi_watchdog=1”EitherinLiloorGruboraddmanuallyatboottimeUsereadprofile-mStartwithreadprofile-r(toresetcounters)Veryeasytouse,butusefulonlyifyouseehighsystemtime.Toprofileuserapplicationsuseoprofile,AcegeneITCo.Ltd.,20,SystemWide,RDA(RemoteDiagnosticAgent),AcegeneITCo.Ltd.,21,Summary:LinuxMonitoringTools,Overalltoolssar,vmstatCPU/proc/cpuinfo,mpstat,topMemory/proc/meminfo,/proc/slabinfoDiskI/Oiostat,sarNetworki