Oracle Cloud Migration Deep Dive

Instructions

Step 1: AWS-to-OCI Concept Mapping

Step 2: Azure-to-OCI Concept Mapping

Step 3: Custom Image Import (AWS AMI to OCI)

Export the AMI from AWS, then import to OCI via Object Storage:

# Step 3a: Export AMI from AWS as VMDK
aws ec2 create-store-image-task \
  --image-id ami-0123456789abcdef0 \
  --bucket my-export-bucket

# Step 3b: Download and upload to OCI Object Storage
aws s3 cp s3://my-export-bucket/ami-0123456789abcdef0.vmdk ./image.vmdk

oci os object put \
  --bucket-name migration-staging \
  --file ./image.vmdk \
  --name "imported-image.vmdk" \
  --namespace "$NAMESPACE"

import oci

config = oci.config.from_file("~/.oci/config")
compute = oci.core.ComputeClient(config)

# Step 3c: Import as OCI custom image
image = compute.create_image(
    oci.core.models.CreateImageDetails(
        compartment_id="COMPARTMENT_OCID",
        display_name="migrated-from-aws",
        image_source_details=oci.core.models.ImageSourceViaObjectStorageTupleDetails(
            source_type="objectStorageTuple",
            bucket_name="migration-staging",
            namespace_name="NAMESPACE",
            object_name="imported-image.vmdk",
            source_image_type="VMDK",
        ),
    )
).data

print(f"Image import started: {image.id}")
print(f"State: {image.lifecycle_state}")  # IMPORTING → AVAILABLE

Step 4: IAM Policy Translation

AWS IAM roles use JSON policies attached to entities. OCI uses human-readable policy statements attached to compartments:

# AWS: Allow EC2 instances to read S3
{
  "Effect": "Allow",
  "Action": ["s3:GetObject", "s3:ListBucket"],
  "Resource": "arn:aws:s3:::my-bucket/*"
}

# OCI equivalent:
allow dynamic-group app-instances to read objects in compartment prod where target.bucket.name='my-bucket'

Common IAM translations:

# Create an OCI IAM policy
oci iam policy create \
  --compartment-id "$COMPARTMENT_OCID" \
  --name "app-compute-policy" \
  --description "Allow app team to manage compute in prod" \
  --statements '["allow group app-team to manage instances in compartment prod","allow group app-team to use volumes in compartment prod"]'

Step 5: Network Topology Translation

Translate an AWS VPC with public/private subnets into an OCI VCN:

# Export AWS VPC configuration
aws ec2 describe-vpcs --vpc-ids vpc-0123456789abcdef0 --output json > aws-vpc.json
aws ec2 describe-subnets --filters "Name=vpc-id,Values=vpc-0123456789abcdef0" --output json > aws-subnets.json
aws ec2 describe-route-tables --filters "Name=vpc-id,Values=vpc-0123456789abcdef0" --output json > aws-routes.json

# Create equivalent OCI VCN
oci network vcn create \
  --compartment-id "$COMPARTMENT_OCID" \
  --display-name "migrated-vcn" \
  --cidr-blocks '["10.0.0.0/16"]' \
  --dns-label "migratedvcn"

Step 6: Data Migration (S3 to Object Storage)

OCI Object Storage supports S3-compatible API, enabling direct migration:

import oci

config = oci.config.from_file("~/.oci/config")
os_client = oci.object_storage.ObjectStorageClient(config)
namespace = os_client.get_namespace().data

# Create destination bucket
os_client.create_bucket(
    namespace_name=namespace,
    create_bucket_details=oci.object_storage.models.CreateBucketDetails(
        compartment_id="COMPARTMENT_OCID",
        name="migrated-data",
        storage_tier="Standard",
    ),
)

# Upload objects (for large migrations, use OCI Data Transfer Service)
with open("data-export.csv", "rb") as f:
    os_client.put_object(
        namespace_name=namespace,
        bucket_name="migrated-data",
        object_name="data-export.csv",
        put_object_body=f,
    )

print(f"Uploaded to: https://objectstorage.{config['region']}.oraclecloud.com/n/{namespace}/b/migrated-data/o/data-export.csv")

S3 Compatibility mode for tools that speak S3 natively:

# OCI Object Storage S3-compatible endpoint
# https://<namespace>.compat.objectstorage.<region>.oraclecloud.com

# Use with aws cli (after configuring OCI customer secret keys)
aws s3 sync s3://source-bucket/ s3://migrated-data/ \
  --endpoint-url "https://NAMESPACE.compat.objectstorage.us-ashburn-1.oraclecloud.com"

Output

Successful completion produces:

• AWS-to-OCI and Azure-to-OCI concept mapping tables for architecture translation
• Custom image imported from VMDK into OCI compute (ready to launch instances)
• IAM policies translated from AWS JSON format to OCI policy statements
• Network topology (VCN, subnets, gateways) matching the source VPC/VNet configuration
• Data migrated from S3 to OCI Object Storage via direct upload or S3-compatible API

Error Handling

Examples

Quick migration pre-flight check:

# Verify OCI compartment is ready
oci iam compartment get --compartment-id "$COMPARTMENT_OCID" \
  --query 'data.{name:name, state:"lifecycle-state"}' --output table

# Verify Object Storage bucket exists
oci os bucket get --bucket-name migration-staging --namespace "$NAMESPACE" \
  --query 'data.name' --raw-output

# Check image import status
oci compute image list --compartment-id "$COMPARTMENT_OCID" \
  --query 'data[?contains("display-name",`migrated`)].{name:"display-name",state:"lifecycle-state"}' \
  --output table

Resources

• OCI Migration Guide — official migration documentation
• OCI Compute Custom Images — image import/export procedures
• OCI S3 Compatibility API — using S3-compatible tools with OCI
• OCI Python SDK Reference — ComputeClient, ObjectStorageClient APIs
• OCI CLI Reference — command-line interface documentation
• OCI Terraform Provider — infrastructure as code for migrated workloads

Next Steps

After migration, review oraclecloud-reference-architecture to validate the OCI topology, then run oraclecloud-prod-checklist to ensure the migrated environment meets production standards.