我有一台16GB RAM的服务器。我试图通过运行
来设置容器的内存限制docker run -it -m 500M <image-name>
在docker统计信息中，它显示容器的内存限制为500MB。但是当我尝试做的时候
docker exec -it <containerID> /bin/sh
并执行“top”，它显示可用内存为16GB ..
不应该设置为500MB吗？
我需要它为500 MB的主要原因是我在每个容器中运行java应用程序。默认情况下，JVM的Xms为16gb / 64，Xmx为4gb。 :(
答案 0 :(得分：2)
我认为这篇文章将帮助您理解为什么free和top在容器内无法正常工作。
Most of the Linux tools providing system resource metrics were created before
cgroups even existed (e.g.: free and top, both from procps). They usually read
memory metrics from the proc filesystem: /proc/meminfo, /proc/vmstat,
/proc/PID/smaps and others.
Unfortunately /proc/meminfo, /proc/vmstat and friends are not containerized.
Meaning that they are not cgroup-aware. They will always display memory
numbers from the host system (physical or virtual machine) as a whole, which
is useless for modern Linux containers
This causes a lot of confusion for users of Linux containers. Why does free
say there is 32GB free memory, when the container only allows 512MB to be
used?
https://fabiokung.com/2014/03/13/memory-inside-linux-containers/