Preconditions

Before starting migration, make sure the following requirements are met.

Magento 2 system

Set up your Magento 2 system so that it meets the system requirements.

Use a topology and design that at least matches your existing Magento 1 system.
Install Magento 2.

Do not start Magento 2 cron jobs.

After installation, back up or dump your Magento 2 database as soon as possible. This allows you to restore the initial database state if migration is not successful.
Verify if the Data Migration Tool has network access to connect the Magento 1 and Magento 2 databases.

Open ports in your firewall so that the Migration Tool can communicate with the databases.
Make sure your MySQL accounts have all the necessary privileges to access Magento databases.

If Binary Logging is enabled for your Magento 1 database, set the global log_bin_trust_function_creators MySQL system variable to 1, or grant the SUPER privilege to your account.
We do not recommend creating new entities (products, categories, attributes, etc.) in your Magento 2 store before migration because the Data Migration Tool overwrites such new entities with the old ones from Magento 1.

Migrate Magento 1 extension code to Magento 2.

To find the latest extensions versions, visit Magento Marketplace or contact your extension provider.

You can also use the Magento Code Migration Tool.

Sep 27th, 2018