Migrate Customers from Magento 1 to Magento 2: Issues & Solutions

• What Main Methods Are Available for Migrating Customer Data?

• Impact of Large Customer Database on Migration Time (500k+ Customers)

• How to Manage Incremental Customer Data Updates During Migration?

• Causes & Resolutions to Customer Data Corruption During Migration

• Comparing Partial Migration vs. Full Migration for Magento 2 Multi-Stores

• FAQs

• Summary

What Main Methods Are Available for Migrating Customer Data?

Three primary methods exist for migrating customer data from Magento 1 to Magento 2:

1. Official Data Migration Tool

The Magento Data Migration Tool moves customer data through direct database transfer. The tool requires command-line knowledge but offers complete data transfer capabilities. You must install the correct version matching your Magento 2 installation.

2. Manual CSV Export/Import

Export customer data from Magento 1 as CSV files. Import these files into Magento 2 through the admin panel. Works best for stores with basic customer structures and smaller databases.

3. Third-Party Migration Services

Professional managed hosting services handle the entire migration process. They provide automated tools and support for complex migrations. These services often include data validation and testing phases.

The complexity and cost associated with each of the migration methods greatly varies:

Method	Complexity	Cost	Best For
Data Migration Tool	High	Free	Large stores
Manual CSV	Medium	Free	Small stores
Third-Party Services	Low	Paid	All sizes

The choice depends on:

• Your technical expertise

• Database size

• Custom customer attributes

• Budget constraints

• Timeline requirements

For most stores, the Data Migration Tool offers the most complete solution. It maintains data integrity and supports incremental updates during migration.

Impact of Large Customer Database on Migration Time (500k+ Customers)

1. Hardware Requirements

• Server RAM needs a minimum of 8GB for smooth migration. Memory limitations cause migration failures and timeouts.

• SSD storage speeds up data transfer rates. Traditional HDDs slow down large data transfers.

• CPU cores affect parallel processing capability. More cores handle customer data chunks faster.

• Network bandwidth must support heavy data transfer. Low bandwidth extends migration duration.

• Temporary storage space needs double the database size. Migration processes create temporary data copies.

2. Data Volume Considerations

• Customer data size affects transfer duration directly. Each additional 100,000 customers adds 2-3 hours.

• Order history increases migration complexity significantly. Past orders require careful mapping.

• Customer attributes need validation before transfer. Custom fields need extra processing time.

• Media files linked to customers need separate handling. Images and documents increase transfer time.

• Database indexes impact migration speed notably. Proper indexing reduces processing time.

3. Network Impact

• Database location affects transfer speeds measurably. Remote databases increase latency issues.

• Connection stability determines migration success rate. Unstable networks cause failed transfers.

• Bandwidth throttling slows down large transfers. Network restrictions extend completion time.

• Peak usage times affect available resources. Schedule migrations during low-traffic periods.

• Distance between servers impacts transfer rates. Closer server locations reduce migration time.

4. Resource Management

• Server load monitoring prevents crashes. High loads pause migration processes.

• Memory allocation needs careful planning. Insufficient memory causes migration failures.

• Backup processes run parallel to migration. Regular backups add to the total duration.

• Cache management affects overall performance. Clear caches before major transfers.

• Database optimization reduces transfer size. Clean databases migrate faster.

5. Testing Requirements

• Data integrity checks add verification time. Each check extends the timeline.

• User acceptance testing needs scheduling blocks. Testing adds 24-48 hours minimum.

• Performance testing requires multiple iterations. Each test cycle needs 4-6 hours.

• Error resolution adds unpredictable delays. Common issues need 2-4 hours each.

• Rollback planning needs separate time allocation. Safety measures extend project duration.

How to Manage Incremental Customer Data Updates During Migration?

Aspect	Implementation	Monitoring	Management
Frontend Updates	Delta tables track new customer registrations and profile changes. Changes sync every 5 seconds automatically. Store owners can view sync logs.	Watch error logs for failed syncs. Check customer data consistency. Monitor database load during syncs.	Disable customer registration during final migration. Plan maintenance windows for large syncs.
Order Processing	New orders create entries in deltalog tables. Order status changes are reflected in both systems. Payment data moves securely.	Track order sync status regularly. Verify payment information accuracy. Check the order numbers sequence.	Process pending orders before the final switch. Keep order IDs consistent across platforms.
Customer Groups	Group changes sync through delta mode. Permission updates move automatically. New groups create matching entries.	Validate group permissions daily. Check customer-group assignments. Monitor group-based pricing.	Update group rules before migration. Document custom group settings.
Address Data	Address updates flow through delta tables. Format changes convert automatically. Validation rules apply to new entries.	Check address format consistency. Verify shipping calculations. Monitor address validation results.	Clean address data before migration. Update address templates if needed.
Custom Attributes	Delta mode captures attribute changes. New attributes need manual mapping. Value updates sync automatically.	Review attribute sync logs daily. Check custom field mappings. Monitor validation errors.	Document custom attribute logic. Test attribute functions post-sync.
Media Files	Customer profile images sync incrementally. File paths update automatically. Storage locations map correctly.	Check media file integrity. Verify image display issues. Monitor storage space usage.	Optimize images before transfer. Update media URLs properly.

Causes & Resolutions to Customer Data Corruption During Migration

1. Incomplete Data Transfers

Cause	Resolution
Data may not fully transfer due to interruptions. System crashes or unstable connections can result in partial data migration.	Use the Magento Data Migration Tool with proper configurations. Always test the migration process in a staging environment.
Large datasets can time out during transfer. This often happens when migrating 500,000+ customer records.	Break the migration into smaller batches to reduce load. Schedule migrations during off-peak hours for better performance.
Missing dependencies between tables can halt transfers. For example, orphaned customer records may not link correctly.	Audit the database for broken relationships before migration. Fix dependencies using database repair tools.

2. Incorrect Data Mapping

Cause	Resolution
Source and target systems may have mismatched fields. For instance, a "phone number" field in Magento 1 might not align with Magento 2.	Map all fields carefully before starting the migration. Use automated tools to identify and resolve mismatches.
Custom attributes in Magento 1 may not exist in Magento 2. These fields can cause errors during transfer.	Create equivalent custom attributes in Magento 2 before migration. Document all custom fields for reference.
Data type differences can corrupt records. For example, numeric fields might convert incorrectly into text fields.	Validate field types in both systems beforehand. Use data validation scripts to check compatibility.

3. Character Encoding Issues

Cause	Resolution
Special characters may fail to migrate correctly. Non-standard encoding formats often lead to unreadable data.	Convert all data into UTF-8 format before migration. Test encoding compatibility using sample datasets.
Multi-language support can complicate character transfers. Languages like Chinese or Arabic may cause encoding conflicts.	Enable multi-language support in Magento 2 settings. Review language-specific fields post-migration for accuracy.
Legacy encoding in Magento 1 may differ from modern standards. This leads to corrupted text fields in Magento 2.	Normalize data encoding during pre-migration audits. Use encoding conversion tools for large datasets.

4. Data Integrity Failures

Cause	Resolution
Duplicate records can create inconsistencies in migrated data. For example, multiple entries for the same customer may appear post-migration.	Deduplicate records using data profiling tools before migration. Run integrity checks after completing the process.
Foreign key constraints might break during transfer. Missing keys lead to incomplete relationships between tables.	Rebuild foreign keys manually or with scripts post-migration. Validate table relationships through database queries.
Corrupted indexes slow down database queries post-migration. This impacts customer search functionality and order history lookups.	Reindex the database immediately after migration completion. Use Magento's built-in reindexing commands.

5. Security and Validation Errors

Cause	Resolution
Unencrypted data transfers expose sensitive information to breaches. It happens especially when migrating customer passwords or payment details.	Encrypt all data during transit using SSL protocols. Store sensitive information securely with hashing algorithms like SHA256.
Validation rules in Magento 2 may reject certain records. Such includes invalid email formats or missing required fields blocking entries.	Adjust validation rules to match Magento 1's structure temporarily during migration. Correct invalid entries manually or through scripts.
Unauthorized access during migration increases risks of tampering or loss. It happens especially with weak access controls exacerbating this issue.	Restrict access to migration tools and databases to authorized personnel only. Monitor activity logs throughout the process.

Comparing Partial Migration vs. Full Migration for Magento 2 Multi-Stores

1. Scope of Data Migration

Aspect	Partial Migration	Full Migration
Data Types Migrated	Transfers only selected data like customers or orders. Useful for businesses reorganizing product catalogs.	Transfers all data, including customers, orders, products, and configurations. Suitable for complete store transitions.
Flexibility	Allows businesses to exclude unnecessary data fields. Reduces migration time and complexity.	Migrates every aspect of the Magento 1 store to Magento 2. Requires more time and resources.
Customization	Offers flexibility to focus on specific data types. Ideal for stores needing fresh product setups.	Maintains the exact structure of the Magento 1 store in Magento 2. Preserves all existing relationships.

2. Migration Time and Complexity

Aspect	Partial Migration	Full Migration
Time Required	Faster due to reduced data volume. Typically completed in hours or days for smaller datasets.	Longer due to transferring all data types. It can take weeks for large-scale stores with complex setups.
Complexity	Simpler process with fewer dependencies to manage. Easier to test and validate post-migration results.	Complex due to interdependencies among data types like products, orders, and customer attributes.
Testing Requirements	Requires testing only for migrated data fields like customer accounts or order history.	Demands comprehensive testing across all migrated entities to verify data accuracy and functionality.

3. Impact on Store Operations

Aspect	Partial Migration	Full Migration
Downtime	Minimal downtime since only selected data is migrated. Allows faster resumption of operations.	Longer downtime as all store functions are paused during migration. Impacts business continuity temporarily.
Business Continuity	Supports ongoing operations. Only focuses on critical data like active customer accounts or orders.	Requires shutting down the Magento 1 store completely during migration. Helps avoid inconsistencies.
Customer Experience	Customers may notice missing historical data, such as past orders. Such occurs when they’re not included in the migration scope.	Provides a simplified experience. Retains all historical customer interactions and records post-migration.

4. Cost Implications

Aspect	Partial Migration	Full Migration
Resource Allocation	Requires fewer resources due to limited data scope. Reduces costs significantly for smaller stores.	Demands higher resource allocation for server capacity. Paid tools and technical expertise needed during migration.
Tool Usage	Supports free or low-cost tools. For example, Magento Data Migration Tool, for selected fields only.	May require advanced tools or services for complete data migration. Increases overall expenses.
Maintenance Costs	Lower maintenance costs post-migration. Fewer configurations are carried over from Magento 1.	Higher maintenance costs. Legacy configurations may need updates in Magento 2 for compatibility.

5. Suitability Based on Business Needs

Aspect	Partial Migration	Full Migration
Business Type	Best suited for businesses revamping their product catalogs. Also useful for stores restructuring operations in Magento 2.	Ideal for businesses seeking a direct replica of their Magento 1 store in Magento 2. Complete migration with no changes.
Data Volume	Suitable for stores with smaller datasets. Stores prioritizing specific entities like customers/orders can also consider.	Recommended for large-scale stores with extensive datasets. Helps with complete transfer of all records.
Long-Term Goals	Works well when planning phased upgrades. Introduces new features incrementally in Magento 2 stores.	Essential when aiming for a one-time transition. Minimal future adjustments post-migration.

FAQs

1. How do I migrate from Magento 1 to Magento 2 using the data migration tool?

First, install the data migration tool matching your Magento 2 version. Create a backup of your store data. Map your database fields. Run the migration command through CLI. Check data integrity after transfer. The tool migrates settings and data automatically.

2. What happens to extensions and themes during migration?

Check if each extension is compatible with Magento 2. Install new Magento 2 extensions before migration. Your Magento 1 theme needs a new version for Magento 2. The migration tool only moves data, not design elements.

3. Can I migrate orders from Magento 1 without moving everything?

Yes. Use partial migration to move specific data like orders. The data migration tool saves current progress. You can migrate order data from Magento 1 separately. Keep your store running during the process.

4. How do I prepare my database for successful migration?

Clean your database before migration starts. Remove unused data. Update to the latest version of Magento 1. Fix any corrupted data entries. Create multiple backups of everything from Magento 1.

5. What should I check after completing the migration?

Test all functionalities in your Magento 2 backend. Verify imported data accuracy. Check if the new Magento 2 store works correctly. Monitor the Magento 2 root directory for errors. Review customer accounts and orders.

Summary

Before migrating customers from Magento 1 to Magento 2, choose the right migration method as per your store. Small stores work well with CSV exports, while larger stores need the Data Migration Tool. Also, consider the following key highlights from the article for easier migration:

1. Plan your server resources before starting migration. Your server needs at least 8GB RAM and SSD storage for faster transfers.

2. Back up all customer data before starting any migration steps. Store multiple copies of your data in different secure locations.

3. Schedule migrations during low-traffic hours to reduce risks. Night-time migrations give you more time to fix any problems.

4. Test the migration process first in a staging environment. Run multiple test cycles to find and fix issues early.

5. Monitor the migration process actively at every step. Keep checking logs and data integrity throughout the transfer process.

Managed Magento hosting includes expert services for both delta and full migration.