docker info提示WARNING: No swap limit support

Posted 2021-02-14 x-knight

问题描述：

　　装完docker后，用docker info ,显示：WARNING: No swap limit support,这句话有什么特别的意思吗？如果是我的虚拟机配置问题，那又需要作哪些改动呢。

[email protected]:~$ sudo docker info
Containers: 0
Running: 0
Paused: 0
Stopped: 0
Images: 0
Server Version: 17.05.0-ce
Storage Driver: aufs
Root Dir: /var/lib/docker/aufs
Backing Filesystem: extfs
Dirs: 0
Dirperm1 Supported: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
Volume: local
Network: bridge host macvlan null overlay
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 9048e5e50717ea4497b757314bad98ea3763c145
runc version: 9c2d8d184e5da67c95d601382adf14862e4f2228
init version: 949e6fa
Security Options:
apparmor
seccomp
Profile: default
Kernel Version: 4.13.0-43-generic
Operating System: Ubuntu 16.04.4 LTS
OSType: linux
Architecture: x86_64
CPUs: 8
Total Memory: 15.57GiB
Name: xknight-optiplex-7040
ID: AWE3:LSXJ:PENS:3QSC:D2BB:5UOL:E4NN:GEUQ:PWJQ:HG5P:25XN:WZAL
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false

WARNING: No swap limit support

 问题解决：

　　根据错误提示，只是cgroups中的swap account没有开启。这个功能应该是用在 `docker run -m=1524288 -it ubuntu /bin/bash` 类似的命令，用来限制一个docker容器的内存使用上限，所以这里只是WARNING，不影响使用。

　　这个默认官方给予解决方法了，地址是https://docs.docker.com/installation/ubuntulinux/

 1 When users run Docker, they may see these messages when working with an image:
 2 WARNING: Your kernel does not support cgroup swap limit. WARNING: Your
 3 kernel does not support swap limit capabilities. Limitation discarded.
 4 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.
 5 Log into Ubuntu as a user with sudo privileges.
 6 Edit the /etc/default/grub file.
 7 Set the GRUB_CMDLINE_LINUX value as follows:
 8 GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1"
 9 Save and close the file.
10 Update GRUB.
11 $ sudo update-grub
12 Reboot your system.