[系统运维]Docker文件存储系统

docker image inspect nginx # 查看nginx镜像一些信息，着重关注GraphDriver字段

[
    {
        "Id": "sha256:c919045c4c2b0b0007c606e763ed2c830c7b1d038ce878a3c0d6f5b81e6ab80b",
        "RepoTags": [
            "nginx:latest"
        ],
        "RepoDigests": [
            "nginx@sha256:1c13bc6de5dfca749c377974146ac05256791ca2fe1979fc8e8278bf0121d285"
        ],
        "Parent": "",
        "Comment": "",
        "Created": "2022-03-01T14:00:05.875390518Z",
        "Container": "62aea4acb75db8685ce9869daf8e2548b1fd56315a562ca80cef5502966ba9ca",
        "ContainerConfig": {
            "Hostname": "62aea4acb75d",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "80/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "NGINX_VERSION=1.21.6",
                "NJS_VERSION=0.7.2",
                "PKG_RELEASE=1~bullseye"
            ],
            "Cmd": [
                "/bin/sh",
                "-c",
                "#(nop) ",
                "CMD [\"nginx\" \"-g\" \"daemon off;\"]"
            ],
            "Image": "sha256:90bc50855dba56bcf29fb414e328f2bbe93d21ad4629139a2b0d37be1f139c9d",
            "Volumes": null,
            "WorkingDir": "",
            "Entrypoint": [
                "/docker-entrypoint.sh"
            ],
            "OnBuild": null,
            "Labels": {
                "maintainer": "NGINX Docker Maintainers <docker-maint@nginx.com>"
            },
            "StopSignal": "SIGQUIT"
        },
        "DockerVersion": "20.10.12",
        "Author": "",
        "Config": {
            "Hostname": "",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "ExposedPorts": {
                "80/tcp": {}
            },
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
                "NGINX_VERSION=1.21.6",
                "NJS_VERSION=0.7.2",
                "PKG_RELEASE=1~bullseye"
            ],
            "Cmd": [
                "nginx",
                "-g",
                "daemon off;"
            ],
            "Image": "sha256:90bc50855dba56bcf29fb414e328f2bbe93d21ad4629139a2b0d37be1f139c9d",
            "Volumes": null,
            "WorkingDir": "",
            "Entrypoint": [
                "/docker-entrypoint.sh"
            ],
            "OnBuild": null,
            "Labels": {
                "maintainer": "NGINX Docker Maintainers <docker-maint@nginx.com>"
            },
            "StopSignal": "SIGQUIT"
        },
        "Architecture": "amd64",
        "Os": "linux",
        "Size": 141505630,
        "VirtualSize": 141505630,
        "GraphDriver": {
            "Data": {
                "LowerDir": "/var/lib/docker/overlay2/07dd3d078460c0938d25ed82709ca476fe2c5794359a852d2190da5609dde5ee/diff:/var/lib/docker/overlay2/c004089c0a68a4aa35421508953a2f180b90853bfe485f016ef0aaa76f3e0c1b/diff:/var/lib/docker/overlay2/9ebd0774db5f681d6263a4bf1200050cadc7bed628f32de0ab605dcaf4f15285/diff:/var/lib/docker/overlay2/1247b8ef4b52db7ccd18d13e8f850303eddc733dfa3bd30b1f2d0944f26ee3bb/diff:/var/lib/docker/overlay2/9d4d2f766b4873b8ea6b0f881ea90c8bdf268cb4faea1e88a5f2c8c09cdb7b39/diff",
                "MergedDir": "/var/lib/docker/overlay2/2bb0398f5d2ed85bc416c13e784c42276a651725ff3aed7b76d50b7cb970152a/merged",
                "UpperDir": "/var/lib/docker/overlay2/2bb0398f5d2ed85bc416c13e784c42276a651725ff3aed7b76d50b7cb970152a/diff",
                "WorkDir": "/var/lib/docker/overlay2/2bb0398f5d2ed85bc416c13e784c42276a651725ff3aed7b76d50b7cb970152a/work"
            },
            "Name": "overlay2"
        },
        "RootFS": {
            "Type": "layers",
            "Layers": [
                "sha256:1401df2b50d5de5a743b7bac3238ef3b7ce905ae39f54707b0ebb8eda3ab10bc",
                "sha256:57a9a0cdd450687265b5d49d47e8dc707f178772faa43a7b01c2299cd39113b7",
                "sha256:3baebd9b50ad6c27671bb9748f3f44922650c46f04977a7857c0366390920afb",
                "sha256:d3ae25fc9f7a917bcd2c3158eff7dc5fc848157e724efdb9af9ffe3771cda464",
                "sha256:53db376e88c7ebd83d9b30e0d20ee818787c21d97c2bd365b02cf23487592007",
                "sha256:e4b39f9495876939f14376f32d7c7ba83526636a8a8b52c008ab32ade9ba6e06"
            ]
        },
        "Metadata": {
            "LastTagTime": "0001-01-01T00:00:00Z"
        }
    }
]

LowerDir

/var/lib/docker/overlay2/07dd3d078460c0938d25ed82709ca476fe2c5794359a852d2190da5609dde5ee/diff
/var/lib/docker/overlay2/c004089c0a68a4aa35421508953a2f180b90853bfe485f016ef0aaa76f3e0c1b/diff
# 3.Nginx启动命令
/var/lib/docker/overlay2/9ebd0774db5f681d6263a4bf1200050cadc7bed628f32de0ab605dcaf4f15285/diff

# 2. Nginx软件包
/var/lib/docker/overlay2/1247b8ef4b52db7ccd18d13e8f850303eddc733dfa3bd30b1f2d0944f26ee3bb/diff

# 1.小型Linux
/var/lib/docker/overlay2/9d4d2f766b4873b8ea6b0f881ea90c8bdf268cb4faea1e88a5f2c8c09cdb7b39/diff