json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "additionalProperties": false,
      "definitions": {
          "entry": {
              "$schema": "http://json-schema.org/draft-04/schema#",
              "definitions": {
                  "diskDevice": {
                      "additionalProperties": false,
                      "properties": {
                          "device": {
                              "pattern": "^/dev/[^/]+(/[^/]+)*$",
                              "type": "string"
                          },
                          "type": {
                              "enum": [
                                  "disk"
                              ]
                          }
                      },
                      "required": [
                          "type",
                          "device"
                      ]
                  },
                  "diskUUID": {
                      "additionalProperties": false,
                      "properties": {
                          "label": {
                              "pattern": "^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}$",
                              "type": "string"
                          },
                          "type": {
                              "enum": [
                                  "disk"
                              ]
                          }
                      },
                      "required": [
                          "type",
                          "label"
                      ]
                  },
                  "nfs": {
                      "additionalProperties": false,
                      "properties": {
                          "remotePath": {
                              "pattern": "^(/[^/]+)+$",
                              "type": "string"
                          },
                          "server": {
                              "anyOf": [
                                  {
                                      "format": "host-name"
                                  },
                                  {
                                      "format": "ipv4"
                                  },
                                  {
                                      "format": "ipv6"
                                  }
                              ],
                              "type": "string"
                          },
                          "type": {
                              "enum": [
                                  "nfs"
                              ]
                          }
                      },
                      "required": [
                          "type",
                          "server",
                          "remotePath"
                      ]
                  },
                  "tmpfs": {
                      "additionalProperties": false,
                      "properties": {
                          "sizeInMB": {
                              "maximum": 512,
                              "minimum": 16,
                              "type": "integer"
                          },
                          "type": {
                              "enum": [
                                  "tmpfs"
                              ]
                          }
                      },
                      "required": [
                          "type",
                          "sizeInMB"
                      ]
                  }
              },
              "description": "schema for an fstab entry",
              "properties": {
                  "fstype": {
                      "enum": [
                          "ext3",
                          "ext4",
                          "btrfs"
                      ]
                  },
                  "options": {
                      "items": {
                          "type": "string"
                      },
                      "minItems": 1,
                      "type": "array",
                      "_uniqueItems": true
                  },
                  "readonly": {
                      "type": "boolean"
                  },
                  "storage": {
                      "oneOf": [
                          {
                              "$ref": "#/definitions/entry/definitions/diskDevice"
                          },
                          {
                              "$ref": "#/definitions/entry/definitions/diskUUID"
                          },
                          {
                              "$ref": "#/definitions/entry/definitions/nfs"
                          },
                          {
                              "$ref": "#/definitions/entry/definitions/tmpfs"
                          }
                      ],
                      "type": "object"
                  }
              },
              "required": [
                  "storage"
              ],
              "type": "object"
          }
      },
      "patternProperties": {
          "^(/[^/]+)+$": {
              "$ref": "#/definitions/entry"
          }
      },
      "properties": {
          "/": {
              "$ref": "#/definitions/entry"
          }
      },
      "required": [
          "/"
      ],
      "type": "object"
  }