Migrate data

Before you start, take the following steps to prepare:

Log in to your application server as the file system owner.
Change to the application installation directory or make sure it is added to your system PATH.

See the first steps section for more details.

Run the data migration command

To start migrating data, run:

bin/magento migrate:data [-r|--reset] [-a|--auto] {<path to config.xml>}

Where:

[-a|--auto] is an optional argument that prevents migration from stopping when it encounters integrity check errors.
[-r|--reset] is an optional argument that starts migration from the beginning. You can use this argument for testing migration.
{<path to config.xml>} is the absolute file system path to config.xml; this argument is required

Within this step, the Data Migration Tool creates additional tables and triggers for the migration tables in the Magento 1 database. They are used in the incremental/delta migration step. Additional tables contain information about changed records after the final migration execution. Database triggers are used to populate these extra tables, so if a new operation is being performed on the particular table (a record is added/modified/removed), these database trigger save information about this operation to the extra table. When we run a delta migration process, the Data Migration Tool checks these tables for the unprocessed records and migrates the necessary content into the Magento 2 database.

Each new table contains:

m2_cl prefix
INSERT, UPDATE, DELETE event triggers.

For example, for the sales_flat_order the Data Migration Tool creates:

m2_cl_sales_flat_order table:

CREATE TABLE `m2_cl_sales_flat_order` (
  `entity_id` int(11) NOT NULL COMMENT 'Entity_id',
  `operation` text COMMENT 'Operation',
  `processed` tinyint(1) NOT NULL DEFAULT '0' COMMENT 'Processed',
  PRIMARY KEY (`entity_id`)
) COMMENT='m2_cl_sales_flat_order';

trg_sales_flat_order_after_insert, trg_sales_flat_order_after_update, trg_sales_flat_order_after_delete triggers:

DELIMITER ;;
CREATE TRIGGER `trg_sales_flat_order_after_insert` AFTER INSERT ON `sales_flat_order`
  FOR EACH ROW
  BEGIN
   INSERT INTO m2_cl_sales_flat_order (`entity_id`, `operation`) VALUES (NEW.entity_id, 'INSERT')ON DUPLICATE KEY UPDATE operation = 'INSERT';
  END
;;

DELIMITER ;;
CREATE TRIGGER `trg_sales_flat_order_after_update` AFTER UPDATE ON `sales_flat_order`
  FOR EACH ROW
  BEGIN
   INSERT INTO m2_cl_sales_flat_order (`entity_id`, `operation`) VALUES (NEW.entity_id, 'UPDATE') ON DUPLICATE KEY UPDATE operation = 'UPDATE';
  END
;;

DELIMITER ;;
CREATE TRIGGER `trg_sales_flat_order_after_delete` AFTER DELETE ON `sales_flat_order`
  FOR EACH ROW
  BEGIN
   INSERT INTO m2_cl_sales_flat_order (`entity_id`, `operation`) VALUES (OLD.entity_id, 'DELETE')ON DUPLICATE KEY UPDATE operation = 'DELETE';
  END
;;

NOTE

The Data Migration Tool saves its current progress as it runs. If errors or a user intervention stops it from running, the Tool resumes progress at the last known good state. To force the Data Migration Tool to run from the beginning, use the --reset argument. In that case, we recommend you restore your Magento 2 database dump to prevent duplicating previously migrated data.

Possible consistency errors

While running, the Data Migration Tool may report inconsistencies between Magento 1 and Magento 2 databases, and display messages like the following:

Source documents are missing: <EXTENSION_TABLE_1>,<EXTENSION_TABLE_2>,...<EXTENSION_TABLE_N>
Destination documents are missing: <EXTENSION_TABLE_1>,<EXTENSION_TABLE_2>,...<EXTENSION_TABLE_N>
Source documents are not mapped: <EXTENSION_TABLE_1>,<EXTENSION_TABLE_2>,...<EXTENSION_TABLE_N>
Destination documents are not mapped: <EXTENSION_TABLE_1>,<EXTENSION_TABLE_2>,...<EXTENSION_TABLE_N>
Source fields are missing. Document: <EXTENSION_TABLE>. Fields: <FIELD_1>,<FIELD_2>...<FIELD_N>
Destination fields are missing. Document: <EXTENSION_TABLE>. Fields: <FIELD_1>,<FIELD_2>...<FIELD_N>
Source fields are not mapped. Document: <EXTENSION_TABLE>. Fields: <FIELD_1>,<FIELD_2>...<FIELD_N>
Destination fields are not mapped. Document: <EXTENSION_TABLE>. Fields: <FIELD_1>,<FIELD_2>...<FIELD_N>
Mismatch of data types. Source document: <EXTENSION_TABLE>. Fields: <FIELD_1>,<FIELD_2>...<FIELD_N>
Mismatch of data types. Destination document: <EXTENSION_TABLE>. Fields: <FIELD_1>,<FIELD_2>...<FIELD_N>
Incompatibility in data. Source document: <EXTENSION_TABLE>. Field: <FIELD>. Error: <ERROR_MESSAGE>
Incompatibility in data. Destination document: <EXTENSION_TABLE>. Field: <FIELD>. Error: <ERROR_MESSAGE>