背景
在以前docker開發運維的時候，經常遇到一個情況，使用top/free命令的時候，把整個物理機的資源讀出來了，lxcfx主要解決這個問題
https://github.com/lxc/lxcfs
Introduction
LXCFS is a small FUSE filesystem written with the intention of making Linux containers feel more like a virtual machine. It started as a side-project of LXC but is useable by any runtime.
LXCFS will take care that the information provided by crucial files in procfs such as:
/proc/cpuinfo
/proc/diskstats
/proc/meminfo
/proc/stat
/proc/swaps
/proc/uptime
/proc/slabinfo
/sys/devices/system/cpu
/sys/devices/system/cpu/online
（簡單翻譯一下，就是在執行上面命令的時候，顯示虛擬機容器信息，而不是物理機信息）
are container aware such that the values displayed (e.g. in /proc/uptime) really reflect how long the container is running and not how long the host is running.
Prior to the implementation of cgroup namespaces by Serge Hallyn LXCFS also provided a container aware cgroupfs tree. It took care that the container only had access to cgroups underneath it's own cgroups and thus provided additional safety. For systems without support for cgroup namespaces LXCFS will still provide this feature but it is mostly considered deprecated.