docker存储引擎----存储引擎的修改

找一台centos7.2安装docker

# yum install -y vim wget telnet lrzsz tree yum-utils device-mapper-persistent lvm2 bash-comple*

# source /usr/share/bash-completion/bash_completion

# rm -rf /etc/yum.repos.d/*

# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

# wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo

# wget -O /etc/yum.repos.d/docker-ce.repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

# yum makecache fast

# wget https://mirrors.aliyun.com/docker-ce/linux/centos/7/x86_64/stable/Packages/docker-ce-18.09.9-3.el7.x86_64.rpm

# yum localinstall docker-ce-*

# systemctl start docker

查看存储引擎

[root@localhost ~]# docker info

...

 Server Version: 18.09.9
 Storage Driver: devicemapper
  Pool Name: docker-8:3-33951780-pool
  Pool Blocksize: 65.54kB
  Base Device Size: 10.74GB
  Backing Filesystem: xfs
  Udev Sync Supported: true
  Data file: /dev/loop0
  Metadata file: /dev/loop1
  Data loop file: /var/lib/docker/devicemapper/devicemapper/data
  Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
  Data Space Used: 11.8MB
  Data Space Total: 107.4GB

...

WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
WARNING: the devicemapper storage-driver is deprecated, and will be removed in a future release.
WARNING: devicemapper: usage of loopback devices is strongly discouraged for production use.
         Use `--storage-opt dm.thinpooldev` to specify a custom block storage device.

配置镜像加速

[root@localhost ~]# vim /etc/docker/daemon.json
{
  "registry-mirrors": ["https://05eotbde.mirror.aliyuncs.com"]
}

  [root@localhost ~]# systemctl daemon-reload
  [root@localhost ~]# systemctl restart docker

拉取一个镜像并启动容器

[root@localhost ~]# docker pull nginx

[root@localhost ~]# docker run -itd -p 80:80 --name test nginx
eed6fd358800d695eb83e4b509dfe082351a005adf07c00e733eaadf730fbb43

修改docker存储引擎为overlay

修改或创建 /etc/docker/daemon.json，并添加

[root@localhost ~]# vim /etc/docker/daemon.json 
{
  "registry-mirrors": ["https://05eotbde.mirror.aliyuncs.com"],
  "storage-driver": "overlay"
}

或者修改unit文件

[root@localhost ~]# vim /lib/systemd/system/docker.service 

...

ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock -s=overlay
ExecReload=/bin/kill -s HUP $MAINPID

...

重启docker，这时候会有报错

[root@localhost ~]# systemctl daemon-reload

[root@localhost ~]# systemctl restart docker
Job for docker.service failed because the control process exited with error code. See "systemctl status docker.service" and "journalctl -xe" for details.

查看日志

Jul 10 23:57:57 localhost dockerd: Error starting daemon: error initializing graphdriver: overlay: the backing xfs filesystem is formatted without d_type support, which leads to incorrect behavior. Reformat the filesystem with ftype=1 to enable d_type support. Backing filesystems without d_type support are not supported.

添加一块200G的硬盘，重启使磁盘识别

[root@localhost ~]# fdisk -l /dev/sdb

Disk /dev/sdb: 214.7 GB, 214748364800 bytes, 419430400 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

摘掉挂载umount /var/lib/docker

注意：可能会出现umount: /var/lib/docker: target is busy.

关闭占用进程fuser -km /var/lib/docker（慎用fuser -km）。在psmisc包中yum install psmisc -y

或者systemctl stop docker再次进行卸载

创建文件系统为xfs，使用参数 -n ftype=1

[root@localhost ~]# mkfs.xfs -n ftype=1 /dev/sdb
meta-data=/dev/sdb               isize=256    agcount=4, agsize=13107200 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=0        finobt=0
data     =                       bsize=4096   blocks=52428800, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal log           bsize=4096   blocks=25600, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

备份：需要使用docker save备份镜像

注意：如果你原先有不同存储驱动的层数据，更换存储驱动后将不可用，建议备份镜像并清除 /var/lib/docker 下所有数据。

备份镜像可以用 docker save 导出镜像，之后用 docker load 导入镜像。

挂载磁盘，启动docker

[root@localhost ~]# mount /dev/sdb /var/lib/docker

[root@localhost ~]# systemctl start docker

查看docker存储引擎

[root@localhost ~]# docker info
...

 Server Version: 18.09.9
 Storage Driver: overlay
  Backing Filesystem: xfs
  Supports d_type: true
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Plugins:
  Volume: local
  Network: bridge host macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive

...

查看之前拉取的nginx镜像和容器是否存在

[root@localhost ~]# docker images
REPOSITORY   TAG       IMAGE ID   CREATED   SIZE


[root@localhost ~]# docker ps -a
CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

 下面演示恢复数据

# docker run -itd --name test -p 80:80 nginx

# docker commit test test1
sha256:5cbae254377047bcb127a7bd8e42c30022513ec0cbbaeabec580b486a38fdc1e

# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
test1               latest              5cbae2543770        7 seconds ago       133MB
nginx               latest              4cdc5dd7eaad        4 days ago          133MB

# docker save nginx >nginx.tar.gz
# docker save test1 >test1.tar.gz

修改存储引擎，重启docker

# vim /etc/docker/daemon.json 
{
  "registry-mirrors": ["https://05eotbde.mirror.aliyuncs.com"],
  "storage-driver": "overlay"
}

# systemctl daemon-reload
# systemctl restart docker

恢复数据

# docker load -i nginx.tar.gz 
ace9ed9bcfaf: Loading layer [==================================================>]  64.86MB/64.86MB
48b4a40de359: Loading layer [==================================================>]  3.072kB/3.072kB
c553c6ba5f13: Loading layer [==================================================>]  4.096kB/4.096kB
d97733c0a3b6: Loading layer [==================================================>]  3.584kB/3.584kB
9d1af766c818: Loading layer [==================================================>]  7.168kB/7.168kB
Loaded image: nginx:latest


# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
nginx               latest              4cdc5dd7eaad        4 days ago          133MB
redis               latest              08502081bff6        2 weeks ago         105MB

 另外：如果是存储引擎修改回来，那么改回来就可以使用原来的镜像了（下面只演示了overlay改为overlay2）

# vim /etc/docker/daemon.json 
{
  "registry-mirrors": ["https://05eotbde.mirror.aliyuncs.com"],
  "storage-driver": "overlay2"
}
# systemctl daemon-reload
# systemctl restart docker

查看镜像

[root@docker04 ~]# docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
test1               latest              5cbae2543770        18 minutes ago      133MB
nginx               latest              4cdc5dd7eaad        4 days ago          133MB