Domain 1: Fundamentals of Cloud Migrations (10%)

Domain 1 of the 1Z0-1123-25 OCI Migration Architect Professional exam covers the foundational principles of cloud migration: why organizations migrate, what strategies they use, how they assess readiness, and how Oracle's frameworks guide the process. This domain represents approximately 5 questions on the exam. Despite the low weight, it establishes vocabulary and concepts that every other domain builds on.

1. Key Drivers for Cloud Adoption

Understanding why organizations migrate to OCI is foundational. The exam tests whether you can identify the correct business or technical driver for a given scenario.

Business Drivers

Technical Drivers

Exam trap: Cost savings alone are rarely the correct sole answer. Oracle's framework emphasizes that a strong business case must address both tangible financial benefits (TCO reduction) and intangible benefits (agility, time to market, competitive advantage). (OCI Business Case)

2. Challenges During Migration

The exam expects you to identify which challenges apply to a given migration scenario and recommend appropriate mitigations.

Exam trap: Organizational challenges (people, process) are tested as heavily as technical ones. The Oracle Cloud Adoption Framework explicitly lists People Strategy and Process Design as two of its six pillars. A technically sound migration plan that ignores organizational readiness will fail. (OCI CAF)

3. The 7 Rs of Migration Strategy

This is the most directly testable topic in Domain 1. You must match each strategy to the correct scenario and understand the tradeoffs.

Decision Criteria for Selecting a Strategy

Exam trap: Relocate and Rehost are not the same thing. Relocate moves the entire virtualization layer (e.g., VMware to OCVS) with zero application changes. Rehost moves individual VMs to OCI Compute instances, which requires boot volume conversion and may need configuration adjustments. The Oracle Cloud Migrations service supports Rehost, not Relocate.

4. Migration Workflow Phases

Oracle defines a four-phase migration methodology: Plan, Prepare, Execute, and Validate. (Oracle Cloud Migration Hub) The Oracle Cloud Migrations service operationalizes this into three workflow phases.

Oracle Cloud Migrations Service Workflow

Phase 1: Manage Assets (Discovery)

• Establish connectivity to source environment (VMware or AWS)
• VMware uses an agent-based approach: deploy a Remote Agent Appliance
• AWS uses an agentless approach: direct OCI-initiated connection
• Automatically discover compute, storage, and networking resources
• Store discovered assets in an Inventory database within the OCI tenancy
• Collect performance data stored in OCI Monitoring service
• Refresh inventory on-demand or via automated Discovery Schedule

(Cloud Migrations Overview)

Phase 2: Plan and Migrate Assets

• Create a Migration Project (logical container grouping migration assets and plans)
• Recommendation Engine generates initial target configuration based on discovered attributes and performance statistics
• Create multiple migration plans for different scenarios (smoke testing, integration testing, load testing, cost analysis)
• Each migration plan includes a monthly cost estimate
• Data replication is independent of planning and uses HTTPS
• Incremental replication is supported
• Data is replicated once to a specific availability domain; each plan clones the replicated data

Phase 3: Verify Migration

• Integrates with OCI Resource Manager (Terraform) for target deployment
• Running a migration plan: clones data, generates a Resource Manager Stack, applies target configuration, performs automated remediation
• Validation is performed outside the Cloud Migrations service
• If verification fails: terminate resources, update replication, re-run plan
• Mark migration project complete to lock configuration (prevents accidental changes to verified production resources)

Exam trap: Replication and planning are independent processes. You can replicate data before finalizing your target configuration. You do not need to complete planning before starting replication.

Key Terminology

5. Assessment Methodology

Migration assessment is the systematic evaluation of the source environment to determine what to migrate, how to migrate it, and what it will cost. The exam tests all five assessment dimensions.

Compute Assessment

Storage and Data Assessment

Network and Security Assessment

Compliance Assessment

The OCI CAF Risk and Compliance documentation defines a 12-step regulatory analysis process:

1. Identify applicable regulations by geography and industry
2. Assemble a cross-functional compliance team
3. Research and document specific regulatory requirements
4. Identify data types and sensitivity levels (PII, financial, health records)
5. Map data flows between on-premises and cloud
6. Interpret regulations for cloud-specific applicability
7. Perform gap analysis against current practices
8. Conduct Data Privacy Impact Assessment (DPIA)
9. Develop compliance strategy with specific controls
10. Collaborate with legal and compliance experts
11. Review and obtain stakeholder approval
12. Document and maintain audit-ready records

Exam trap: Compliance is not just about where data is stored. It includes data flows (how data moves between environments), access controls (who can see the data), audit logging (proving compliance), and breach response (notification timelines). The exam may present scenarios where data residency is satisfied but another compliance dimension is not.

Application Assessment

6. Oracle Cloud Adoption Framework (CAF)

The OCI CAF provides prescriptive guidance across six pillars. Each pillar is independently addressable, and the framework is iterative.

Exam trap: The CAF is not a linear, one-time process. It is iterative. Organizations revisit pillars as priorities evolve. A question may present a scenario where an organization skips directly to Technology Implementation without completing Business Strategy or People Strategy -- this is incorrect according to the framework.

7. Total Cost of Ownership (TCO) Analysis

The OCI Business Case documentation defines TCO as the sum of all costs involved in purchasing, operating, and maintaining IT assets over their lifetime.

On-Premises Cost Categories (What You Compare Against)

OCI Cost Advantages

Tangible vs. Intangible Benefits

Exam trap: TCO analysis must include opportunity costs -- the cost of NOT migrating. A like-to-like cost comparison (on-premises server cost vs. OCI compute cost) is insufficient. The business case must also account for what the organization loses by staying on-premises: slower innovation, hardware refresh cycles, inability to scale elastically.

8. OCI Migration Tools Summary

Key Concepts for Exam Preparation

Quick-Reference Decision Matrix

Likely Exam Traps Summary

1. Rehost is not Relocate -- Rehost moves individual VMs to OCI Compute; Relocate moves the entire VMware layer to OCVS.
2. Replication is independent of planning -- You can replicate data before your migration plan is finalized.
3. VMware discovery is agent-based; AWS discovery is agentless -- Do not confuse the two connectivity models.
4. TCO must include intangible benefits and opportunity costs -- A pure hardware cost comparison is incomplete.
5. CAF is iterative, not linear -- Pillars can be revisited; skipping pillars is an anti-pattern.
6. Compliance goes beyond data residency -- Access controls, audit logging, breach notification, and data flow mapping are all compliance dimensions.
7. The Recommendation Engine suggests shapes, not mandates -- Its output is a customizable starting point, not a final configuration.
8. Temporary migration resources are billed -- Hydration agents, temporary VCNs, and Object Storage buckets created during migration incur normal OCI charges.

References

1. Oracle Cloud Migrations Overview -- Service architecture, workflow phases, terminology
2. Oracle Cloud Adoption Framework -- Six pillars, iterative methodology
3. OCI CAF Business Case -- TCO analysis, ROI methodology, cost categories
4. OCI CAF Risk and Compliance -- 12-step regulatory analysis, risk register, compliance frameworks
5. OCI Value Proposition -- Price-performance data, security architecture, deployment flexibility
6. Oracle Cloud Migration Hub -- Migration tools, supported workloads, four-phase methodology
7. 1Z0-1123-25 Exam Page -- Official exam objectives and format