3.7. Docker 存储

Docker 存储的后端使用以下两个选项之一：第一个选项是代设备映射器的精简池逻辑卷；另一个（从 Red Hat Enterprise Linux version 7.4 开始）是使用一个 overlay2 文件系统通常建议使用 overlay2 文件系统，因为设置更轻松则性能更高。

Docker 存储磁盘挂载为 /var/lib/docker，并格式化为 xfs 文件系统。Docker 存储配置为使用 overlay2 文件系统：

$ cat /etc/sysconfig/docker-storage
DOCKER_STORAGE_OPTIONS='--storage-driver overlay2'

Docker 验证此存储驱动程序是否使用了：

# docker info
Containers: 4
 Running: 4
 Paused: 0
 Stopped: 0
Images: 4
Server Version: 1.12.6
Storage Driver: overlay2
 Backing Filesystem: xfs
Logging Driver: journald
Cgroup Driver: systemd
Plugins:
 Volume: local
 Network: overlay host bridge null
 Authorization: rhel-push-plugin
Swarm: inactive
Runtimes: docker-runc runc
Default Runtime: docker-runc
Security Options: seccomp selinux
Kernel Version: 3.10.0-693.11.1.el7.x86_64
Operating System: Employee SKU
OSType: linux
Architecture: x86_64
Number of Docker Hooks: 3
CPUs: 2
Total Memory: 7.147 GiB
Name: ocp-infra-node-1clj
ID: T7T6:IQTG:WTUX:7BRU:5FI4:XUL5:PAAM:4SLW:NWKL:WU2V:NQOW:JPHC
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://registry.redhat.io/v1/
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
Insecure Registries:
 127.0.0.0/8
Registries: registry.redhat.io (secure), registry.redhat.io (secure), docker.io (secure)