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Docker 数据卷

数据卷（Volume）是 Docker 提供的一种机制，用于在容器之间共享数据或在容器和主机之间持久化数据。数据卷可以帮助你管理容器的数据，使其在容器重启或删除后仍然保留。

卷就是目录或文件，存在于一个或者多个容器中，由Docker挂载到容器，但不属于联合文件系统，因此能够绕开 Union File System 提供一些用于持续存储或共享数据的特性。

卷设计的目的就是数据的持久化，完全独立于容器的生命周期，因此Docker不会在删除容器时删除其挂载的数据卷。

一、权限扩容​

--privileged=true

Docker挂载主机目录访问如果出现cannotopendirectory: Permissiondenied

解决办法：在挂载目录后多加一个--privileged=true参数即可

如果是CentOS7安全模块会比之前系统版本加强，不安全的会先禁止，所以目录挂载的情况被默认为不安全的行为， 在SELinux里面挂载目录被禁止掉了，如果要开启，我们一般使用--privileged=true命令，扩大容器的权限解决挂载目录没有权限的问题， 也即使用该参数，container内的root拥有真正的root权限。否则，container内的root只是外部的一个普通用户权限。

二、数据卷的使用​

-v /host/path:/container/path --privileged=true

默认情况下，-v参数会创建数据卷到/var/lib/容器名目录下。

Docker数据卷

docker run -it -v /host/path:/container/path --privileged=true 镜像名称 /bin/bash

  • docker run：创建并启动一个新的容器

  • -it：以交互模式运行容器，并分配一个伪终端

  • -v /host/path:/container/path：将主机的/host/path目录挂载到容器的/container/path目录

  • --privileged=true：扩展容器权限，解决挂载目录没有权限的问题

  • 镜像名称:标签：指定要运行的镜像名称和标签（标签可选，默认是latest）

  • /bin/bash：指定容器启动后执行的命令

  • -d：后台运行容器（detached）并返回容器ID（启动守护模式容器）

  • --name：为容器指定一个名称

数据卷可以在容器之间共享或重用数据，卷中的数据更改可以直接实时生效，数据卷中的更改不会包含到镜像中的更新，数据卷的生命周期持续到没有容器使用它为止。

1.宿主机与容器间映射添加容器卷​

docker run -it -v /host/path:/container/path --privileged=true 镜像名称 /bin/bash

如果在执行上述命令时，没有指定的映射目录，Docker会自动创建相应的目录。

信息

查看数据卷是否挂载成功

docker inspect 容器ID

输出容器内部的详细信息

[
  {
    "Id": "93bf1bef9d38817b1e9637c9b3afe1d737f09fd3b038a198dc0a1d3d48cd7290",
    "Created": "2025-09-24T02:08:22.436382004Z",
    "Path": "/bin/bash",
    "Args": [],
    "State": {
      "Status": "running",
      "Running": true,
      "Paused": false,
      "Restarting": false,
      "OOMKilled": false,
      "Dead": false,
      "Pid": 806490,
      "ExitCode": 0,
      "Error": "",
      "StartedAt": "2025-09-24T02:08:22.526221287Z",
      "FinishedAt": "0001-01-01T00:00:00Z"
    },
    "Image": "sha256:be65f488b7764ad3638f236b7b515b3678369a5124c47b8d32916d6487418ea4",
    "ResolvConfPath": "/var/lib/docker/containers/93bf1bef9d38817b1e9637c9b3afe1d737f09fd3b038a198dc0a1d3d48cd7290/resolv.conf",
    "HostnamePath": "/var/lib/docker/containers/93bf1bef9d38817b1e9637c9b3afe1d737f09fd3b038a198dc0a1d3d48cd7290/hostname",
    "HostsPath": "/var/lib/docker/containers/93bf1bef9d38817b1e9637c9b3afe1d737f09fd3b038a198dc0a1d3d48cd7290/hosts",
    "LogPath": "/var/lib/docker/containers/93bf1bef9d38817b1e9637c9b3afe1d737f09fd3b038a198dc0a1d3d48cd7290/93bf1bef9d38817b1e9637c9b3afe1d737f09fd3b038a198dc0a1d3d48cd7290-json.log",
    "Name": "/elegant_joliot",
    "RestartCount": 0,
    "Driver": "overlayfs",
    "Platform": "linux",
    "MountLabel": "",
    "ProcessLabel": "",
    "AppArmorProfile": "docker-default",
    "ExecIDs": [
      "dd0a53e118f6e91d319d2aadd039aa571062e2859383eb6c2e4e025a9dd78b71"
    ],
    "HostConfig": {
      "Binds": [
        "/Users/dxm/tmp:/tmp"
      ],
      "ContainerIDFile": "",
      "LogConfig": {
        "Type": "json-file",
        "Config": {}
      },
      "NetworkMode": "bridge",
      "PortBindings": {},
      "RestartPolicy": {
        "Name": "no",
        "MaximumRetryCount": 0
      },
      "AutoRemove": false,
      "VolumeDriver": "",
      "VolumesFrom": null,
      "ConsoleSize": [
        63,
        272
      ],
      "CapAdd": null,
      "CapDrop": null,
      "CgroupnsMode": "private",
      "Dns": [],
      "DnsOptions": [],
      "DnsSearch": [],
      "ExtraHosts": null,
      "GroupAdd": null,
      "IpcMode": "private",
      "Cgroup": "",
      "Links": null,
      "OomScoreAdj": 0,
      "PidMode": "",
      "Privileged": false,
      "PublishAllPorts": false,
      "ReadonlyRootfs": false,
      "SecurityOpt": null,
      "UTSMode": "",
      "UsernsMode": "",
      "ShmSize": 67108864,
      "Runtime": "runc",
      "Isolation": "",
      "CpuShares": 0,
      "Memory": 0,
      "NanoCpus": 0,
      "CgroupParent": "",
      "BlkioWeight": 0,
      "BlkioWeightDevice": [],
      "BlkioDeviceReadBps": [],
      "BlkioDeviceWriteBps": [],
      "BlkioDeviceReadIOps": [],
      "BlkioDeviceWriteIOps": [],
      "CpuPeriod": 0,
      "CpuQuota": 0,
      "CpuRealtimePeriod": 0,
      "CpuRealtimeRuntime": 0,
      "CpusetCpus": "",
      "CpusetMems": "",
      "Devices": [],
      "DeviceCgroupRules": null,
      "DeviceRequests": null,
      "MemoryReservation": 0,
      "MemorySwap": 0,
      "MemorySwappiness": null,
      "OomKillDisable": null,
      "PidsLimit": null,
      "Ulimits": [],
      "CpuCount": 0,
      "CpuPercent": 0,
      "IOMaximumIOps": 0,
      "IOMaximumBandwidth": 0,
      "MaskedPaths": [
        "/proc/asound",
        "/proc/acpi",
        "/proc/kcore",
        "/proc/keys",
        "/proc/latency_stats",
        "/proc/timer_list",
        "/proc/timer_stats",
        "/proc/sched_debug",
        "/proc/scsi",
        "/sys/firmware",
        "/sys/devices/virtual/powercap"
      ],
      "ReadonlyPaths": [
        "/proc/bus",
        "/proc/fs",
        "/proc/irq",
        "/proc/sys",
        "/proc/sysrq-trigger"
      ]
    },
    "GraphDriver": {
      "Data": null,
      "Name": "overlayfs"
    },
    "Mounts": [
      {
        "Type": "bind",
        "Source": "/Users/dxm/tmp",
        "Destination": "/tmp",
        "Mode": "",
        "RW": true,
        "Propagation": "rprivate"
      }
    ],
    "Config": {
      "Hostname": "93bf1bef9d38",
      "Domainname": "",
      "User": "",
      "AttachStdin": false,
      "AttachStdout": false,
      "AttachStderr": false,
      "Tty": true,
      "OpenStdin": true,
      "StdinOnce": false,
      "Env": [
        "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
      ],
      "Cmd": [
        "/bin/bash"
      ],
      "Image": "centos:7",
      "Volumes": null,
      "WorkingDir": "",
      "Entrypoint": null,
      "OnBuild": null,
      "Labels": {
        "org.label-schema.build-date": "20201113",
        "org.label-schema.license": "GPLv2",
        "org.label-schema.name": "CentOS Base Image",
        "org.label-schema.schema-version": "1.0",
        "org.label-schema.vendor": "CentOS",
        "org.opencontainers.image.created": "2020-11-13 00:00:00+00:00",
        "org.opencontainers.image.licenses": "GPL-2.0-only",
        "org.opencontainers.image.title": "CentOS Base Image",
        "org.opencontainers.image.vendor": "CentOS"
      }
    },
    "NetworkSettings": {
      "Bridge": "",
      "SandboxID": "13c6fc35deb75f8b1e412ed51b91b82eed03c541fb2cff01f2cb0f69679ba91a",
      "SandboxKey": "/var/run/docker/netns/13c6fc35deb7",
      "Ports": {},
      "HairpinMode": false,
      "LinkLocalIPv6Address": "",
      "LinkLocalIPv6PrefixLen": 0,
      "SecondaryIPAddresses": null,
      "SecondaryIPv6Addresses": null,
      "EndpointID": "413d6d249898eb76600f3ae213425aef04f00a3b79942e9c67ed3b2f2fb6deef",
      "Gateway": "172.17.0.1",
      "GlobalIPv6Address": "",
      "GlobalIPv6PrefixLen": 0,
      "IPAddress": "172.17.0.3",
      "IPPrefixLen": 16,
      "IPv6Gateway": "",
      "MacAddress": "02:42:ac:11:00:03",
      "Networks": {
        "bridge": {
          "IPAMConfig": null,
          "Links": null,
          "Aliases": null,
          "MacAddress": "02:42:ac:11:00:03",
          "DriverOpts": null,
          "NetworkID": "b35af006230111accbae2c209fe7a222ec236993c739086b24cfed77aa403095",
          "EndpointID": "413d6d249898eb76600f3ae213425aef04f00a3b79942e9c67ed3b2f2fb6deef",
          "Gateway": "172.17.0.1",
          "IPAddress": "172.17.0.3",
          "IPPrefixLen": 16,
          "IPv6Gateway": "",
          "GlobalIPv6Address": "",
          "GlobalIPv6PrefixLen": 0,
          "DNSNames": null
        }
      }
    }
  }
]

2.读写规则映射添加说明​

(1) 读写（默认规则）​

docker run -it -v /host/path:/container/path:rw --privileged=true 镜像名称 /bin/bash

rw：指定当前挂载的数据卷可读可写（默认不写，就是可读可写）

(2) 只读​

docker run -it -v /host/path:/container/path:ro --privileged=true 镜像名称 /bin/bash

ro：指定当前挂载的数据卷只读（限制的是容器的读写权限，不限制宿主机）

3.数据卷继承和共享​

容器与容器的数据卷继承

docker run -it --privileged=true --volumes-from 父类(容器) 镜像名称 /bin/bash

--volumes-from 父类(容器)：创建容器时，指定一个父类容器，继承其挂载的数据卷映射。