Data migration tool and transfer external container data

Discussion created by dansmith65 on Jan 10, 2019
Latest reply on Mar 1, 2019 by TSGal

Only tested with FileMaker Pro Adv. 17.0.3 on both Mac and Windows.


If the path to external container data is changed and the transfer option was used before making a clone for the DMT, the DMT should enable the "Container Data Transfer" for the field, but it doesn't. This line from the FileMaker Data Migration Tool Guide seems to be saying that it will do that:

  • If, during migration, container field storage options are changed, the FileMaker data migration tool does not transfer the container data. To transfer the container data, open the target file with FileMaker Pro Advanced and click Transfer Data in the Manage Containers dialog box.

In reality, to transfer the container data to the new location, you have to do this for every field that had it's path changed:

  1. Open "Manage Database", edit the container options for the field by toggling the "Store container data externally" option to off, then back on again, close "Manage Database".
  2. The "Container Data Transfer" dialog will open and allow you to "Transfer" (or Close and do the transfer at another time via File > Manage > Containers > Transfer Data button).

You can test the above scenario for yourself using the attached files and these steps:

  1. Run the DMT:
    FMDataMigration.exe -src_path source\Untitled.fmp12 -clone_path "cloneA\Untitled Clone.fmp12" -target_path targetA\Untitled.fmp12
  2. Open targetA\Untitled.fmp12
  3. Note that the Container field is defined to use open storage and store in a sub-folder called "new", but the actual container is not stored in that sub-folder, and the Transfer option is not available until you follow the steps above.


Note that this issue only applies when the Transfer option was used prior to creating the clone used in the DMT, as this test will show:

  1. Run the DMT:
    FMDataMigration.exe -src_path source\Untitled.fmp12 -clone_path "cloneB\Untitled Clone.fmp12" -target_path targetB\Untitled.fmp12
  2. Open targetB\Untitled.fmp12
  3. Note that the File > Manage Containers > Transfer Data option is available to use.


"testC" in the attached file demonstrates that a change to the Base Directory for the container acts the same as "testA"



The DMT should enable the "Container Data Transfer" feature for a field in the new file in these scenarios:

  1. It was enabled in the old file (the old file's field was modified, but the transfer feature wasn't used).
  2. The field options (that could affect it's storage location/format) changed between source and clone.

FMDataMigration.exe -src_path source\Untitled.fmp12 -clone_path "cloneB\Untitled Clone.fmp12" -target_path targetB\Untitled.fmp12