Create path mappings

Create path mappings when you want to define an alternative migration path on your target filesystem.

Path mappings will automatically apply to any new migrations.

tip

If path mappings are not required for your migrations, you can start to migrate your data.

Why use path mapping?

When path mapping is not used, the source path on your source filesystem will be created on your target filesystem. This may not always be suitable for the purposes of your migration.

The following example shows a common use-case where the default Hive metastore warehouse directory for Hortonworks is /apps/hive/warehouse, and the default for Azure HDInsight is /hive/warehouse.

Example for Hortonworks to HDInsight	Source path	Target path
Without path mapping	/apps/hive/warehouse	/apps/hive/warehouse
With path mapping	/apps/hive/warehouse	/hive/warehouse

Using path mapping enables any migrated data (relating to managed Hive databases and tables) to be stored in the equivalent default location on the target.

Create a path mapping in the Azure Portal

Add a path mapping

After you create a path mapping, any new migrations automatically applies it (if the path is mapped in the migration boundary).

Add a path mapping by following these steps:

1. In the Azure Portal, navigate to the LiveData Migrator resource page.
2. From the LiveData Migrator menu on the left, select Path Mappings.
3. Select Create.
4. Complete the details under the Basics section:
   • Name: A reference name for your path mapping.
   • Path for Source Filesystem: The directory on your source filesystem to map from.
   • Target Filesystem: Your target filesystem name (ADLS Gen2 storage account and container).
   • Path for Target Filesystem: The directory on your target filesystem to map to.
5. Select Review + create.
6. Check that the path mapping details are correct and then select Review and create.

View a migration to see the applicable path mappings

View the path mappings applied to a migration by following these steps:

1. In the Azure Portal, navigate to the LiveData Migrator resource page.
2. From the LiveData Migrator menu on the left, select Migrations.
3. Select the migration name that you want to view.
4. View the path mappings that have been applied to the migration under the Path Mapping tab.

Remove a path mapping

1. In the Azure Portal, navigate to the LiveData Migrator resource page.
2. From the LiveData Migrator menu on the left, select Path Mappings.
3. Select the path mapping that you want to delete (using the checkbox).
4. Select Delete and confirm the deletion.

note

When a path mapping is deleted, any migrations using the path mapping will not be affected. They will continue to function as if the path mapping were still in place.

Create a path mapping with the Azure CLI

Add a path mapping

Once a path mapping has been created, any new migrations will automatically apply them (if the path being mapped is within the migration boundary).

Run the following command to create a path mapping:

az livedata migrator path-mapping create -g <resource_group> --migrator-name <migrator_name> --path-mapping-name <path_mapping_name> --source-path <source_path> --target-id <target_filesystem_name> --target-path <target_path> --description "<description>"

See the Azure CLI LiveData Extension - Path Mapping Create section for help with these parameters.

Remove a path mapping

Run the following command to remove a path mapping:

az livedata migrator path-mapping delete -g <resource_group> --migrator-name <migrator_name> --path-mapping-name <path_mapping_name>

See the Azure CLI LiveData Extension - Path Mapping Delete section for help with these parameters.

note

When a path mapping is deleted, any migrations using the path mapping will not be affected. They will continue to function as if the path mapping were still in place.

Path mapping limitation

Paths on the source filesystem will not be migrated if they conflict with target paths that are created by the path mapping rules.

An example would be if you had a path mapping rule such as below:

Source path	Target path
/repl/folder/old	/repl/folder/old/archive

In this case, if a new directory is created on the source /repl/folder/old/newdir, it is migrated to the target as /repl/folder/old/archive/newdir.

However, if the following directory is created on the source /repl/folder/old/archive, this would not be migrated as it conflicts with the path mapping rule.

Next steps

Once you have defined any path mappings, you are ready to migrate your data.

Troubleshooting

If you are having problems creating path mappings, you can find solutions in the troubleshooting guide.