free

#以合适的单位显示内存使用情况，最大为三位数，自动计算对应的单位值。
root@aly-hb5-ecs-001:~# free -h
              total        used        free      shared  buff/cache   available
Mem:           3.9G        594M        556M        3.0M        2.7G        3.0G
Swap:            0B          0B          0B

其实 free 命令中的信息都来自于 /proc/meminfo 文件。/proc/meminfo 文件包含了更多更原始的信息，只是看起来不太直观：

root@aly-hb5-ecs-001:~# cat /proc/meminfo
MemTotal:        4046188 kB
MemFree:          569616 kB
MemAvailable:    3125508 kB
Buffers:          466052 kB
Cached:          2196308 kB
SwapCached:            0 kB
Active:          2707456 kB
Inactive:         522744 kB
Active(anon):     568528 kB
Inactive(anon):     2420 kB
Active(file):    2138928 kB
Inactive(file):   520324 kB
Unevictable:           4 kB
Mlocked:               4 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:               156 kB
Writeback:             0 kB
AnonPages:        567840 kB
Mapped:           256228 kB
Shmem:              3116 kB
Slab:             206744 kB
SReclaimable:     186276 kB
SUnreclaim:        20468 kB
KernelStack:        7088 kB
PageTables:         8736 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     2023092 kB
Committed_AS:    3549720 kB
VmallocTotal:   34359738367 kB
VmallocUsed:           0 kB
VmallocChunk:          0 kB
HardwareCorrupted:     0 kB
AnonHugePages:         0 kB
CmaTotal:              0 kB
CmaFree:               0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:       87936 kB
DirectMap2M:     3057664 kB
DirectMap1G:     3145728 kB

Linux free命令

linux下free命令详解

linux free命令详解（一）