Phase 1 – Discovery

The Discovery phase is the foundation of every successful migration project. Before any workload can be assessed, planned, or migrated, organizations must gain complete visibility into their existing environment. This phase focuses on identifying infrastructure assets, applications, dependencies, configurations, performance metrics, and business requirements to build a comprehensive migration inventory.

A well-executed discovery phase minimizes migration risks, uncovers hidden dependencies, and provides the data needed to make informed migration decisions.

The primary objective is to establish a single source of truth for the migration program.

Key Objectives

  • Discover all infrastructure components.
  • Inventory virtual machines, hosts, storage, and networks.
  • Identify application dependencies.
  • Collect performance and utilization metrics.
  • Map business owners and application criticality.
  • Establish the migration baseline.
  • Build a trusted inventory for assessment and planning.

Define Migration Scope

The first step is understanding what will be migrated and why.

Activities

  • Identify business drivers.
  • Define migration objectives.
  • Establish project scope.
  • Determine in-scope and out-of-scope workloads.
  • Identify stakeholders and application owners.

Deliverable: Migration charter and scope definition.

Identify Data Sources

Discovery requires data from multiple enterprise systems.

Infrastructure Sources

  • vCenter Server
  • ESXi Hosts
  • VMware Aria Operations
  • NSX
  • vSAN
  • Storage Arrays
  • Backup Platforms

Enterprise Sources

  • CMDB
  • ITSM platforms
  • Monitoring tools
  • Asset inventory
  • Documentation
  • Cloud platforms

Deliverable: Discovery source inventory.

Infrastructure Inventory Collection

Collect detailed infrastructure information.

Compute

  • Virtual Machines
  • ESXi Hosts
  • Clusters
  • CPU & Memory allocation
  • Resource Pools

Storage

  • Datastores
  • Storage Policies
  • Capacity
  • IOPS
  • Storage Arrays

Network

  • VLANs
  • Virtual Switches
  • Distributed Switches
  • NSX Segments
  • Firewalls
  • Load Balancers

Deliverable: Infrastructure inventory report.

Application Discovery

Understanding applications is as important as understanding infrastructure.

Collect

  • Application name
  • Version
  • Owner
  • Business function
  • Environment (Dev/Test/UAT/Prod)
  • Database
  • Middleware
  • Authentication methods

This information enables application-centric migration planning.

Dependency Discovery

Dependencies are one of the most critical inputs for migration.

Typical dependencies include:

  • Application-to-Application communication
  • Web-to-Database traffic
  • Middleware integration
  • External APIs
  • Active Directory
  • DNS
  • Load Balancers
  • Storage
  • Security services

Outcome: High-level application dependency map.

Performance & Utilization Collection

Historical utilization data prevents over-provisioning and supports right-sizing.

Metrics to Collect

  • CPU utilization
  • Memory consumption
  • Storage growth
  • IOPS
  • Network throughput
  • Peak utilization
  • Resource contention

Collect data over a representative period (typically 30–90 days) to capture business cycles.

Data Validation & Enrichment

Discovery data must be validated before it is used.

Validation Activities

  • Remove duplicate records.
  • Verify VM ownership.
  • Confirm business criticality.
  • Reconcile with CMDB.
  • Fill missing attributes.
  • Validate application relationships.

Enriched data improves the accuracy of downstream assessment and planning.

Discovery Deliverables

The discovery phase concludes with a set of reusable artifacts.

DeliverablePurpose
Infrastructure InventoryBaseline environment
Application InventoryWorkload catalog
Dependency MapApplication relationships
Performance ReportUtilization trends
Network TopologyConnectivity overview
Discovery DashboardExecutive visibility
Data Quality ReportInventory validation
Migration InventoryInput for assessment

Discovery Dashboard

Discovery Progress
──────────────────────────────────────────

Infrastructure Inventory     ██████████ 100%

Application Discovery        █████████░ 96%

Dependency Mapping           ████████░░ 88%

Performance Collection       ██████████ 100%

CMDB Validation              █████████░ 93%

Business Ownership           ████████░░ 90%

Discovery Complete           █████████░ 95%

Best Practices

  • Combine automated discovery with stakeholder workshops for complete visibility.
  • Collect performance data over multiple weeks to avoid sizing based on short-term peaks.
  • Validate and enrich inventory before starting the assessment phase.
  • Prioritize application dependency mapping early to reduce migration risk.
  • Maintain a centralized discovery repository as the authoritative source for the migration program.
  • Engage application owners early to verify business context and criticality.

Common Discovery Challenges

ChallengeMitigation
Incomplete inventoryUse multiple discovery sources and validate with stakeholders
Unknown application ownersReconcile with CMDB and business units
Hidden dependenciesUse network flow analysis and application mapping tools
Duplicate or outdated dataNormalize and cleanse discovery results
Inconsistent namingApply standardized naming conventions and tagging