memory and swap accounting是什么？

memory and swap accounting是 统计Linux内核的内存和交换区

为什么需要开启memory and swap？

这是docker官方提示的内容

Adjust memory and swap accounting
When users run Docker, they may see these messages when working with an image:

WARNING: Your kernel does not support cgroup swap limit. WARNING: Your
kernel does not support swap limit capabilities. Limitation discarded.
To prevent these messages, enable memory and swap accounting on your system. To enable these on system using GNU GRUB (GNU GRand Unified Bootloader), do the following.

Log into Ubuntu as a user with sudo privileges.

Edit the /etc/default/grub file.

Set the GRUB_CMDLINE_LINUX value as follows:

GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1"
Save and close the file.

Update GRUB.

$ sudo update-grub
Reboot your system.

这两个特性具体有什么意义，其实我也没搞太清楚。猜测是用来限制一个docker容器的内存使用上限。

开启步骤

开启 memory and swap on system 使用 GNU GRUB (GNU GRand Unified Bootloader)，步骤如下:

1. 使用具有 sudo 权限的用户登录你的系统。
2. 编辑 /etc/default/grub 文件。
3. 设置 GRUB_CMDLINE_LINUX 的值如下：

GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1"

4. 保存并关闭文件。
5. 更新 GRUB。

$ sudo update-grub

6.重启你的系统