Compute Scan & Resource Inventory

The Both option in DMC runs a Compute Scan and a Resource Inventory together in a single pass. This is the recommended choice for most Azure assessments, giving Dr Migrate VM performance data, guest-level detail, and a complete inventory of all Azure services without requiring a second scan run.

Before you start¶

Complete all steps in Azure Requirements before running this scan. You will need:

An Azure Service Principal with Tenant ID, Client ID, Client Secret, and Subscription ID
Reader role at subscription scope (required for Resource Inventory)
Virtual Machine Contributor role (or equivalent) if using Managed Run Command for guest access
One guest access method configured: Managed Run Command (recommended), WinRM, or SSH
A Storage Account SAS URI if using Managed Run Command (used to receive script output from VMs)

Running the scan¶

On the DMC main screen, select Azure, then select Both when prompted to choose a scan type. The wizard then runs five steps.

Azure Subscription¶

Click Add Azure Identity + and choose your authentication method:

Manual SPN: Enter Tenant ID, Client ID (Application ID), Client Secret, and Subscription ID. Optionally provide a Storage SAS URI (required for Managed Run Command output) and comma-separated resource group names to restrict scope.
Managed Identity: DMC uses the managed identity of the Azure VM it runs on. Optionally specify a user-assigned Client ID, then click Connect & list subscriptions to select which subscriptions to include.

Click Test & Save. DMC validates connectivity and RBAC permissions and displays the number of VMs and resource groups found.

Guest Credentials¶

Add Windows and/or Linux administrator credentials for guest OS scanning (software inventory, network dependencies, SQL Server instances). If you provided a Storage SAS URI in the previous step, Managed Run Command is available and credentials are not required. Click Next to proceed.

Settings¶

Configure three tabs:

General: Output path for scan results and logs; maximum concurrent servers (VMs processed in parallel); metric collection duration in days (1–90, default 30) and granularity in minutes (default 15).
Compute: Scan thresholds. DMC skips guest scanning on a VM if CPU usage exceeds the threshold (default 85%), memory exceeds the threshold (default 75%), or free disk space is below the minimum (default 2 GB Windows C:\, 2 GB Linux /, 0.5 GB Linux /tmp). Guest execution methods: enable or disable Run Command and WinRM/SSH per OS type.
Resource Inventory: Cost data collection. Enable Collect cost data to pull rolled-up spend from Azure Cost Management (requires Cost Management Reader role). Choose collection scope (per subscription or management group) and cost period (default: last 12 full months plus current month). Optionally enable resource-level cost detail, which collects per-resource daily cost for the last 14 days and is slower. Azure Resource Inventory: all resource types are selected by default. Deselect any categories you do not need.

Run the scan¶

The Scan screen shows the total VMs discovered, VMs in scope, and per-subscription status. Click Run Scan. DMC runs the Resource Inventory first, then begins guest scanning across all VMs in scope. Real-time progress is shown in the console output and a progress bar tracks VMs completed.

Azure Cost Management API throttling (HTTP 429) is expected and handled automatically. DMC retries with exponential backoff. Throttling warnings in the console output do not indicate a failure.

Export results¶

When the scan completes, proceed to the Results screen to export your scan file and import it into Dr Migrate.