Create path mappings

Create path mappings when you want to define an alternative target path for a specific target filesystem.

Why use path mapping?

If you don't map paths, the source path on your source filesystem is created on your target filesystem. This may not always be suitable for 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.

Limitations

• Internal path mappings and Target Match are incompatible and not allowed to be used in conjunction.
• Conflicting paths, see Path mapping limitation for information and example conflicts.

Create a path mapping with the UI

You can create path mappings through the UI. To access path mappings:

• From your Dashboard, select your instance under Instances.
• Under the Migrations menu, select Path Mappings.

Here, you will see a list of any existing path mappings.

Add a path mapping

To add a path mapping, select Add new path mapping.

In the form that appears, enter the following details:

• Name: A reference name for your path mapping.
• Source Filesystem: The filesystem source. Selectable via a drop-down menu.
• Path for <Source_Filesystem_Name>: The directory path on the source filesystem to map from. Appears only after selecting a source filesystem.
• Target Filesystem: The target filesystem to map to in migrations. Selectable via a drop-down menu.
• Path for <Target_Filesystem_Name>: The directory path on the target filesystem to map to. Appears only after selecting a target filesystem.

Select Add once you've entered all necessary information to create your new path mapping. The path mapping is then added to the Path Mappings tab.

Remove a path mapping

To delete a path mapping, locate the path mapping you want to remove in the list and select the trash can icon next to it.

note

When you delete a path mapping, migrations using the path mapping aren't affected. They continue to function as if the path mapping were still in place.

Create a path mapping with the CLI

Add path mappings

Use the path mapping add command to define your source and target paths, as well as your target filesystem.

Manage path mappings

Command	Action
path mapping delete	Delete a path mapping
path mapping list	List all path mappings or list path mappings for a specific filesystem
path mapping show	Show details of a specified path mapping

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 and exclusions, you're ready to migrate data.