AD on VM or AADS

Question

seeking assistance on which active directory is more cost effective to deploy, service difference.

Answer 1

Hi Boyet Pore,

The main difference comes down to cost and management overhead. Running AD on a VM gives you full control, but you’ll need to pay for the VM compute, storage, Windows Server licensing, and handle patching and maintenance yourself. This can add up quickly, especially if you need high availability.

On the other hand, AADS is a managed service provided by Microsoft. It eliminates the need to maintain domain controllers, and Microsoft takes care of updates, scaling, and availability. This usually makes AADS more cost‑effective for small to mid‑sized organizations or those moving toward cloud‑native infrastructure.

Feature‑wise, AD on VM supports advanced scenarios like schema extensions, forest trusts, and Group Policy Objects. AADS supports core directory services and integrates seamlessly with Azure, but it doesn’t allow schema extensions or complex trust relationships. If your environment requires those advanced features, AD on VM is the better fit despite the higher cost.

If your goal is simplicity, reduced management effort, and lower long‑term cost, AADS is the recommended option. If you need full flexibility and legacy AD features, AD on VM is the way to go.

I hope the response provided some helpful insight. If it addressed your issue, please consider marking it as Accept Answer so others facing the same problem can easily find the solution. If you need any further assistance, feel free to leave a comment.

Jason.

Answer 2

Hi Boyet Pore,

I’m following up to check whether the issue has been resolved. Feel free to reply if you need further information. If the information provided was helpful, please click "Accept Answer" to help others in the community. Thank you!

Answer 3

For most scenarios, Microsoft Entra Domain Services (managed domain) is more cost‑effective and simpler to operate than running self‑managed AD DS on Azure VMs, but the right choice depends on required features and admin control.

Key service differences

1. Identity options in Azure

• Active Directory Domain Services (AD DS)
  • Traditional, self‑managed directory on Windows Server VMs.
  • Provides full AD DS capabilities: identity and authentication, computer object management, Group Policy, trusts, schema extensions.
• Microsoft Entra ID
  • Cloud-based identity for Microsoft 365, SaaS apps, and modern auth (OAuth/OpenID Connect).
  • Can sync with on‑prem AD DS.
• Microsoft Entra Domain Services (managed domain)
  • Managed domain that exposes classic AD features (Kerberos/NTLM, LDAP, domain join, Group Policy) for Azure workloads.
  • Integrates with Microsoft Entra ID, which can itself sync from on‑prem AD DS.

2. Managed domain (Microsoft Entra Domain Services) vs self‑managed AD DS on VMs

Managed domain (Entra Domain Services)

• Managed service: Core AD DS infrastructure (DCs, OS, patching, replication) is operated by Microsoft.
• Features provided:
  • Domain join, NTLM/Kerberos authentication.
  • DNS server (managed), LDAP read/write within the managed domain.
  • Group Policy, custom OU structure.
  • Secure LDAP (LDAPS).
  • Forest trusts (with Enterprise SKU).
  • Geo-distributed deployments.
• Limitations vs self‑managed AD DS:
  • No domain/enterprise admin privileges.
  • No schema extensions.
  • Kerberos constrained delegation is resource‑based only.
• Best suited for:
  • Azure server VMs that need classic AD auth but where minimizing admin overhead is important.
  • Lift‑and‑shift apps that expect LDAP/Kerberos/NTLM.

Self‑managed AD DS on Azure VMs

• You deploy and manage Windows Server VMs as domain controllers in an Azure virtual network.
• Full AD DS feature set:
  • Domain/enterprise admin privileges.
  • Schema extensions.
  • Forest/domain trusts.
  • Both resource‑based and account‑based Kerberos constrained delegation.
• Common deployment models:
  • Standalone cloud‑only AD DS.
  • Extension of on‑prem AD DS into Azure via VPN/ExpressRoute and replica DCs.
• Responsibilities:
  • Design and maintain forests, domains, sites, replication.
  • Patch, secure, back up, and monitor DC VMs and OS.
• Best suited for:
  • Complex AD requirements, custom schema, advanced trusts, or full control needs.

3. Cost‑effectiveness considerations

Managed domain (Entra Domain Services)

• Cost drivers:
  • Service SKU (capacity tier) and region.
• Cost optimizations:
  • Can be deployed as a shared service for multiple workloads to lower per‑workload cost.
• Operational cost:
  • Lower: Microsoft handles DC infrastructure, patching, and much of the complexity.

Self‑managed AD DS on VMs

• Cost drivers:
  • Azure VMs for DCs (size, count, region, uptime).
  • Storage, backup, and networking (VPN/ExpressRoute if extending on‑prem).
• Operational cost:
  • Higher: design, deployment, patching, security hardening, monitoring, and troubleshooting are all administrator responsibilities.

4. When to choose which

Choose Microsoft Entra Domain Services when:

• Workloads are primarily Azure VMs needing classic AD auth.
• Minimal management overhead is a priority.
• No need for schema extensions or full domain/enterprise admin control.

Choose self‑managed AD DS on Azure VMs when:

• Full AD DS capabilities are required (schema extensions, complex trusts, advanced delegation).
• There is an existing AD DS skillset and operational capacity.
• Tight integration or extension of an existing on‑prem AD DS design is needed.

For learning and planning, see the training module on deploying and managing Azure IaaS domain controllers and the comparison of identity solutions.

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References:

• Compare self-managed Active Directory Domain Services, Microsoft Entra ID, and managed Microsoft Entra Domain Services
• Deploy AD DS in an Azure virtual network
• Deploy and manage Azure IaaS Active Directory domain controllers in Azure