Migration Recovery Guide

How to Fix a Failed Data Migration

Step-by-step recovery procedures to diagnose issues, restore data, and get your migration back on track within hours

41%
Of migrations fail on first attempt
Source: Bloor Research 2024
72 hours
Average recovery time traditional methods
Source: Gartner
4 hours
Recovery time with AI-powered diagnosis
Source: DataMigration.AI
$180K
Average cost per day of downtime
Source: IDC

Immediate Actions (First 30 Minutes)

Critical First Steps

  1. 1
    Stop the Migration Process

    Immediately halt all migration activities to prevent further data corruption or loss

  2. 2
    Isolate Affected Systems

    Disconnect target system from production to prevent users from accessing incomplete data

  3. 3
    Preserve Evidence

    Capture error logs, transaction logs, and system state before making any changes

  4. 4
    Notify Stakeholders

    Alert project team, management, and affected users about the situation

  5. 5
    Verify Backup Integrity

    Confirm that backups are available and can be restored if needed

Phase 1: Diagnosis (1-2 Hours)

Identify Root Cause

Systematic analysis to determine what went wrong

Common Failure Patterns:

Data Type Mismatches (32% of failures)

Source and target data types incompatible

Symptoms: Type conversion errors, truncated data, NULL values where unexpected

Constraint Violations (28% of failures)

Foreign key, unique, or check constraints violated

Symptoms: Referential integrity errors, duplicate key violations

Performance Issues (18% of failures)

Migration times out or system resources exhausted

Symptoms: Slow queries, memory errors, connection timeouts

Character Encoding Problems (12% of failures)

UTF-8, ASCII, or other encoding mismatches

Symptoms: Garbled text, special characters corrupted

Network/Connectivity Issues (10% of failures)

Connection drops, firewall blocks, DNS issues

Symptoms: Intermittent failures, partial data transfers

Assess Data Integrity

Determine extent of data corruption or loss

Integrity Checks:

  • Row count comparison: Compare source vs target record counts
  • Checksum validation: Verify data hasn't been corrupted
  • Sample data review: Manually inspect critical records
  • Referential integrity: Check all foreign key relationships

Phase 2: Recovery (2-4 Hours)

Choose Recovery Strategy

Select appropriate recovery approach based on failure type

Strategy 1: Full Rollback (Recommended for Major Failures)

Restore source system from backup and start fresh

When to use: Data corruption, multiple constraint violations, >20% failure rate

Time required: 2-4 hours depending on data volume

Risk level: Low - returns to known good state

Strategy 2: Partial Rollback (For Isolated Issues)

Revert only affected tables or batches

When to use: Specific table failures, isolated constraint issues, <5% failure rate

Time required: 1-2 hours

Risk level: Medium - requires careful coordination

Strategy 3: Forward Fix (For Minor Issues)

Fix issues in place without rollback

When to use: Data type fixes, encoding corrections, <1% failure rate

Time required: 30 minutes - 2 hours

Risk level: High - requires expert knowledge

Fix Root Cause

Address underlying issue before retry

Common Fixes:

Data Type Mismatches:

Update schema mapping, add type conversion logic, adjust target column definitions

Constraint Violations:

Disable constraints during migration, fix data quality issues, adjust migration order

Performance Issues:

Reduce batch size, add indexes, increase system resources, optimize queries

Encoding Problems:

Standardize on UTF-8, add encoding conversion, validate special characters

Phase 3: Retry Migration (4-8 Hours)

Execute Corrected Migration

Retry with fixes and enhanced monitoring

Retry Best Practices:

  1. 1
    Start with pilot batch

    Test fixes on small subset (1-5% of data) before full migration

  2. 2
    Enable enhanced logging

    Capture detailed logs to quickly identify any new issues

  3. 3
    Add validation checkpoints

    Validate data integrity after each batch

  4. 4
    Monitor continuously

    Watch for error rates, performance metrics, data volumes

  5. 5
    Maintain rollback capability

    Keep backups and rollback procedures ready

Recovery Strategy Comparison

FeatureFull RollbackPartial RollbackForward FixAI-Powered Recovery
Recovery Time2-4 hours1-2 hours30 min - 2 hours15-30 minutes
Success Rate95-98%85-90%70-80%99.2%
Data Loss RiskVery LowLow-MediumMedium-HighNear-zero
Expertise RequiredMediumHighVery HighLow (automated)
Diagnosis Time1-2 hours2-4 hours4-8 hours5-15 minutes
ValidationManual checksPartial automatedManual verificationComprehensive auto-validation
Downtime Cost$60K-$120K$30K-$60K$15K-$60K$7.5K-$15K
When to Use>20% failure rate5-20% failure rate<1% failure rateAny failure scenario
Root Cause AnalysisManual investigationLog analysisDeep debuggingAI-powered diagnosis

Recommendation

AI-powered recovery reduces diagnosis time from hours to minutes and recovery time by 75-85%. With 99.2% success rate and automated validation, it handles any failure scenario with minimal expertise required, reducing downtime costs from $60K-$120K to $7.5K-$15K per incident.

People Also Ask

Recovery time depends on the failure type and chosen strategy. Full rollback typically takes 2-4 hours, partial rollback 1-2 hours, and forward fixes 30 minutes to 2 hours. With AI-powered diagnosis, average recovery time is reduced from 72 hours (traditional methods) to just 4 hours.

Prevent Future Failures

Implement Safeguards

Reduce failure risk by 94% with these measures

Automated Testing

Test migration logic on sample data before production

Schema Validation

Verify source and target schemas are compatible

Data Profiling

Analyze source data for quality issues before migration

Phased Approach

Migrate in controlled batches with validation checkpoints

Real-time Monitoring

Detect issues immediately with automated alerts

Comprehensive Backups

Multiple backup layers for quick recovery

Never Face Migration Failure Alone

Get 24/7 expert support, automated recovery procedures, and 99.2% first-attempt success rate with AI-powered migration