linux内存排查

1. 查看内存使用情况

• free -h

  li@app:~$ free -h
                total        used        free      shared  buff/cache   available
  Mem:          3.8Gi       554Mi       2.1Gi       222Mi       1.1Gi       2.7Gi
  Swap:         3.8Gi       168Mi       3.6Gi
  

2. 查看进程占用的内存空间

• top

  shift+m：查看进程占用内存排序

  shift+p: 查看进程使用的cpu排序

      PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND                                                          
      357 root      19  -1  155108 101012  99548 S   0.0   2.6   2:36.60 systemd-journal                                                  
  1783482 48        20   0  511940  67748  59400 S   0.0   1.7   0:53.69 php-fpm                                                          
  1887140 48        20   0  513260  67112  57160 S   0.0   1.7   0:49.32 php-fpm                                                          
   732833 48        20   0  509856  66632  56460 S   0.0   1.7   1:15.89 php-fpm                             
  1887374 48        20   0  425160  62324  54828 S   0.0   1.6   0:39.60 php-fpm                                                                           
   732831 48        20   0  507552  58644  51648 S   0.0   1.5   0:45.06 php-fpm                                                          
  1887449 48        20   0  421052  55500  48456 S   0.0   1.4   0:12.02 php-fpm                                                  
     1176 root      20   0  936252  49688  12356 S   0.0   1.3   9:04.06 dockerd                             
  

3. 动态监控硬件资源变化

• vmstat

  vmstat 5	#每5秒收集一次
  
  li@app:~$ vmstat 5
  procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
   r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
   0  0 172288 2194368  29392 1158780    0    0    12    15    7    2  0  0 99  0  0
   0  0 172288 2194360  29392 1158820    0    0     0     0  171  287  0  0 100  0  0
   0  0 172288 2194360  29400 1158820    0    0     0     8  160  288  0  0 100  0  0
   0  0 172288 2194360  29400 1158820    0    0     0     1  164  337  0  0 100  0  0