Copy data from or to Azure File Storage by using Azure Data Factory

This article outlines how to use the Copy Activity in Azure Data Factory to copy data from and to Azure File Storage (Azure Files). It builds on the copy activity overview article that presents a general overview of copy activity.

Supported capabilities

You can copy data from Azure File Storage to any supported sink data store, or copy data from any supported source data store to Azure File Storage. For a list of data stores that are supported as sources/sinks by the copy activity, see the Supported data stores table.

Specifically, this Azure File Storage connector supports copying files as-is or parsing/generating files with the supported file formats and compression codecs.

Getting started

You can create a pipeline with the copy activity by using one of the following tools or SDKs. Select a link to go to a tutorial with step-by-step instructions to create a pipeline with a copy activity.

The following sections provide details about properties that are used to define Data Factory entities specific to Azure File Storage.

Linked service properties

The following properties are supported for Azure File Storage linked service:

Property Description Required
type The type property must be set to: FileServer. Yes
host Specifies the Azure File Storage endpoint as "host": "\\\\<storage name>.file.core.windows.net\\<file service name>". Yes
userid Specify the user to access the Azure File Storage as "userid": "AZURE\\<storage name>". Yes
password Specify the storage access key. Mark this field as a SecureString to store it securely in Data Factory, or reference a secret stored in Azure Key Vault. Yes
connectVia The Integration Runtime to be used to connect to the data store. You can use Azure Integration Runtime or Self-hosted Integration Runtime (if your data store is located in private network). If not specified, it uses the default Azure Integration Runtime. No for source, Yes for sink

Important

  • To copy data into Azure File Storage using Azure Integration Runtime, explicitly create an Azure IR with the location of your File Storage, and associate in the linked service as the following example.
  • To copy data from/to Azure File Storage using Self-hosted Integration Runtime outside of Azure, remember to open outbound TCP port 445 in your local network.

Example:

{
    "name": "AzureFileStorageLinkedService",
    "properties": {
        "type": "FileServer",
        "typeProperties": {
            "host": "\\\\<storage name>.file.core.windows.net\\<file service name>",
            "userid": "AZURE\\<storage name>",
            "password": {
                "type": "SecureString",
                "value": "<storage access key>"
            }
        },
        "connectVia": {
            "referenceName": "<name of Integration Runtime>",
            "type": "IntegrationRuntimeReference"
        }
    }
}

Dataset properties

For a full list of sections and properties available for defining datasets, see the datasets article. This section provides a list of properties supported by Azure File Storage dataset.

To copy data from/to Azure File Storage, set the type property of the dataset to FileShare. The following properties are supported:

Property Description Required
type The type property of the dataset must be set to: FileShare Yes
folderPath Path to the folder. Wildcard filter is not supported. Yes
fileName Name or wildcard filter for the file(s) under the specified "folderPath". If you don't specify a value for this property, the dataset points to all files in the folder.

For filter, allowed wildcards are: * (matches zero or more characters) and ? (matches zero or single character).
- Example 1: "fileName": "*.csv"
- Example 2: "fileName": "???20180427.txt"
Use ^ to escape if your actual file name has wildcard or this escape char inside.

When fileName isn't specified for an output dataset and preserveHierarchy isn't specified in the activity sink, the copy activity automatically generates the file name with the following format: "Data.[activity run id GUID].[GUID if FlattenHierarchy].[format if configured].[compression if configured]". An example is "Data.0a405f8a-93ff-4c6f-b3be-f69616f1df7a.txt.gz".
No
format If you want to copy files as-is between file-based stores (binary copy), skip the format section in both input and output dataset definitions.

If you want to parse or generate files with a specific format, the following file format types are supported: TextFormat, JsonFormat, AvroFormat, OrcFormat, ParquetFormat. Set the type property under format to one of these values. For more information, see Text Format, Json Format, Avro Format, Orc Format, and Parquet Format sections.
No (only for binary copy scenario)
compression Specify the type and level of compression for the data. For more information, see Supported file formats and compression codecs.
Supported types are: GZip, Deflate, BZip2, and ZipDeflate.
Supported levels are: Optimal and Fastest.
No

Tip

To copy all files under a folder, specify folderPath only.
To copy a single file with a given name, specify folderPath with folder part and fileName with file name.
To copy a subset of files under a folder, specify folderPath with folder part and fileName with wildcard filter.

Note

If you were using "fileFilter" property for file filter, it is still supported as-is, while you are suggested to use the new filter capability added to "fileName" going forward.

Example:

{
    "name": "AzureFileStorageDataset",
    "properties": {
        "type": "FileShare",
        "linkedServiceName":{
            "referenceName": "<Azure File Storage linked service name>",
            "type": "LinkedServiceReference"
        },
        "typeProperties": {
            "folderPath": "folder/subfolder/",
            "fileName": "myfile.csv.gz",
            "format": {
                "type": "TextFormat",
                "columnDelimiter": ",",
                "rowDelimiter": "\n"
            },
            "compression": {
                "type": "GZip",
                "level": "Optimal"
            }
        }
    }
}

Copy activity properties

For a full list of sections and properties available for defining activities, see the Pipelines article. This section provides a list of properties supported by Azure File Storage source and sink.

Azure File Storage as source

To copy data from Azure File Storage, set the source type in the copy activity to FileSystemSource. The following properties are supported in the copy activity source section:

Property Description Required
type The type property of the copy activity source must be set to: FileSystemSource Yes
recursive Indicates whether the data is read recursively from the sub folders or only from the specified folder. Note when recursive is set to true and sink is file-based store, empty folder/sub-folder will not be copied/created at sink.
Allowed values are: true (default), false
No

Example:

"activities":[
    {
        "name": "CopyFromAzureFileStorage",
        "type": "Copy",
        "inputs": [
            {
                "referenceName": "<Azure File Storage input dataset name>",
                "type": "DatasetReference"
            }
        ],
        "outputs": [
            {
                "referenceName": "<output dataset name>",
                "type": "DatasetReference"
            }
        ],
        "typeProperties": {
            "source": {
                "type": "FileSystemSource",
                "recursive": true
            },
            "sink": {
                "type": "<sink type>"
            }
        }
    }
]

Azure File Storage as sink

To copy data to Azure File Storage, set the sink type in the copy activity to FileSystemSink. The following properties are supported in the sink section:

Property Description Required
type The type property of the copy activity sink must be set to: FileSystemSink Yes
copyBehavior Defines the copy behavior when the source is files from file-based data store.

Allowed values are:
- PreserveHierarchy (default): preserves the file hierarchy in the target folder. The relative path of source file to source folder is identical to the relative path of target file to target folder.
- FlattenHierarchy: all files from the source folder are in the first level of target folder. The target files have auto generated name.
- MergeFiles: merges all files from the source folder to one file. If the File/Blob Name is specified, the merged file name would be the specified name; otherwise, would be auto-generated file name.
No

Example:

"activities":[
    {
        "name": "CopyToAzureFileStorage",
        "type": "Copy",
        "inputs": [
            {
                "referenceName": "<input dataset name>",
                "type": "DatasetReference"
            }
        ],
        "outputs": [
            {
                "referenceName": "<Azure File Storage output dataset name>",
                "type": "DatasetReference"
            }
        ],
        "typeProperties": {
            "source": {
                "type": "<source type>"
            },
            "sink": {
                "type": "FileSystemSink",
                "copyBehavior": "PreserveHierarchy"
            }
        }
    }
]

recursive and copyBehavior examples

This section describes the resulting behavior of the Copy operation for different combinations of recursive and copyBehavior values.

recursive copyBehavior Source folder structure Resulting target
true preserveHierarchy Folder1
    File1
    File2
    Subfolder1
        File3
        File4
        File5
The target folder Folder1 is created with the same structure as the source:

Folder1
    File1
    File2
    Subfolder1
        File3
        File4
        File5.
true flattenHierarchy Folder1
    File1
    File2
    Subfolder1
        File3
        File4
        File5
The target Folder1 is created with the following structure:

Folder1
    auto-generated name for File1
    auto-generated name for File2
    auto-generated name for File3
    auto-generated name for File4
    auto-generated name for File5
true mergeFiles Folder1
    File1
    File2
    Subfolder1
        File3
        File4
        File5
The target Folder1 is created with the following structure:

Folder1
    File1 + File2 + File3 + File4 + File 5 contents are merged into one file with auto-generated file name
false preserveHierarchy Folder1
    File1
    File2
    Subfolder1
        File3
        File4
        File5
The target folder Folder1 is created with the following structure

Folder1
    File1
    File2

Subfolder1 with File3, File4, and File5 are not picked up.
false flattenHierarchy Folder1
    File1
    File2
    Subfolder1
        File3
        File4
        File5
The target folder Folder1 is created with the following structure

Folder1
    auto-generated name for File1
    auto-generated name for File2

Subfolder1 with File3, File4, and File5 are not picked up.
false mergeFiles Folder1
    File1
    File2
    Subfolder1
        File3
        File4
        File5
The target folder Folder1 is created with the following structure

Folder1
    File1 + File2 contents are merged into one file with auto-generated file name. auto-generated name for File1

Subfolder1 with File3, File4, and File5 are not picked up.

Next steps

For a list of data stores supported as sources and sinks by the copy activity in Azure Data Factory, see supported data stores.