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Linux优化-RH442

Introduction​

  • REEL 6.2 64bit OS
  • desktop.exampl.com 192.168.0.x physical student workstation
  • server.example.com 192.168.0.x+100 main student virtual machine
  • host.example.com 192.168.0.x+200 secondary student virtual machine
  • Instructor.example.com 192.168.0.254 physical instruction macine and utility server

性能优化​

  • Black art 黑色艺术
  • Both of the hardware and software
  • 应用场景
  • Tuning goals: Response time or Throughput
  • Performance tuning is undertakein to ...
  • Perforamnce management is the process of ...

Disable Unused Services​

  • service service_name stop
  • chkconfig service_name off
  • service - -status-all
  • yum -y remove bluez

Monitoring vs Profiling​

K = 10^3=1000 2^10=1024 M = 10^6=1,000,000 2^20=1,048,576 G = 10^9 2^30 T = 10^12 2^40 P = 10^15 2^50 E = 10^18 2^60 df -H df -h

# bc scale=8 小数点后位8位 1/6 210^12 210^12/2^40 真实空间 quit

# df -h /1024 # df -H /1000

Unit Conversions​

  • 100Mib/s equals GiB/h
    • 100/8MiB/s => 100/8/1024GiB/s * 3600
  • 43KiB/sec equals MiB/min
  • 20GiB/h equals MiB/s

Profiling Tools​

  • vmstat: Virtual Memory Statistics

  • iostat and mpstat(sysstat package)

  • sar: The System Activity Reporter

  • Using awk to Format Data

  • Plotting data with gnuplot|RRDtool

CPU, Mem, IO, NEt

  • rpm -ql mpstat
  • rpm -ql vmstat
  • rpm -ql iostat
  • rpm -ql mpstat
  • rpm -ql sar

mpstat​

mpstat n m n:时间间隔 m：统计次数 # LANG=C mpstat 1 3 时间以24小时制

HH:MM:SS CPU %usr %nice %sys %iowait %irq %soft %steal %guest

# LANG=C mpstat -P ALL 1 3 # LANG=C mpstat -P 0 1 3 多核CPU第一个 %usr: 用户态CPU占用百分比 %nice： 优先级程序百分比 %sys: 内核态程序百分比 %iowait: 磁盘IO (数值高, 结合iostat) %irq: 系统中断（键盘、鼠标、网卡数据包） %soft: 软件中断（网卡数据包，程序处理） %steal: 虚拟机有关（CPU用于虚拟机进程） %guest: 虚拟机有关（当前系统它所运行的虚拟机） %idle: 空闲百分比

# cat /proc/cpuinfo processor : 几核数，核心, 0单核 module name: flags: vmx(支持虚拟化) # lscpu