升级docker1.12.6到18.09,并切换存储direct-lvm到overlay2

先确保操作系统内核为：3.10.0.862及其以上版本，可通过 uname -r 查看
停止并卸载docker
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    systemctl stop docker && yum remove -y docker*

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删除docker存储，并删除docker目录
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    vgremove docker    #若这一步报devicebusy，则reboot节点之后重新vgremove。  
    pvremove /dev/***  
    rm -rf /var/lib/docker/*

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格式化overlay2存储
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    mkfs.xfs -n ftype=1 /dev/***  
    mount /dev/*** /var/lib/docker

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加入开机启动/etc/fstab
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    /dev/*** /var/lib/docker   xfs defaults 0 0

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安装18.09.2的docker，并修改daemon.json配置文件
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    yum install yum-utils -y  
    yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo  
    yum clean all   
    yum install  docker-ce-18.09.5* -y  
    systemctl enable docker

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修改daemon.json配置文件，默认lvm的配置如下格式：

    [root@cloud-cn-master-1 ~]# cat /etc/docker/daemon.json  
    {  
        "insecure-registries": [  
            "192.168.0.4:60080",  
            "",  
            ""  
        ],  
        "storage-driver": "devicemapper",  
        "storage-opts": [  
            "dm.thinpooldev=/dev/mapper/docker-thinpool",  
            "dm.min_free_space=0%",  
            "dm.use_deferred_deletion=true",  
            "dm.use_deferred_removal=true",  
            "dm.fs=ext4"  
        ]  
    }  
      
    修改后如下所示：  
    {  
        "insecure-registries": [  
            "192.168.0.4:60080",  
            "10.0.0.1:5000"  
        ],  
        "storage-driver": "overlay2"  
    }

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启动docker
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    systemctl start docker  
    systemctl enable docker

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