Enterprise Active Directory & Windows File Services Modernization on AWS
Ashiana Housing Limited
Executive Summary
Ashiana Housing Limited is one of India's leading real estate developers with multiple corporate offices and branch locations across the country. The organization relied on an on-premises Microsoft Active Directory infrastructure, Windows File Server, ERP application, and Hyper-V virtualization platform to support its business-critical operations.
As the business expanded, the customer required a highly available, secure, and scalable Microsoft infrastructure that could eliminate dependency on on-premises systems while improving centralized identity management, application availability, disaster recovery, and operational efficiency.
Zaptoz Technologies successfully migrated the complete Microsoft Active Directory Domain Services (AD DS) environment from the on-premises data center to AWS. The solution included highly available Primary and Additional Domain Controllers across separate Availability Zones, migration of approximately 4 TB of enterprise file data to AWS Windows File Server while preserving NTFS permissions, integration of the ERP application with Active Directory using SAML-based Single Sign-On (SSO), secure Site-to-Site VPN connectivity between the corporate network and AWS, infrastructure rightsizing, and Reserved Instances and Savings Plans to optimize cloud costs.
Current Challenges
Legacy Active Directory Infrastructure
- • Domain Controllers hosted entirely on-premises.
- • Authentication depended on local infrastructure.
- • Limited fault tolerance and disaster recovery.
- • Increasing hardware maintenance costs.
Windows File Server
- • ~4 TB of enterprise data on an aging file server.
- • Storage growth increasingly hard to manage.
- • Backup and recovery required heavy manual effort.
- • Preserving permissions during migration was a risk.
Identity & Access Management
- • ERP operated without centralized authentication.
- • Multiple credentials across enterprise applications.
- • User administration was manual and time-consuming.
Branch Connectivity & Optimization
- • Branch offices connected through MPLS.
- • Head Office secured by a FortiGate firewall.
- • Secure cloud connectivity needed without disruption.
- • Application servers required rightsizing and cost control.
The Solution Offered
Zaptoz Technologies designed and implemented a highly available Microsoft workload architecture on AWS to modernize the customer's identity infrastructure and enterprise services.
- • Complete migration of Active Directory Domain Services (AD DS) to AWS.
- • Primary and Additional Domain Controllers across separate Availability Zones.
- • Active Directory replication for high availability.
- • Migration of ~4 TB of Windows File Server data.
- • Preservation of NTFS permissions and folder-level access controls.
- • Domain integration of ERP application servers.
- • SAML-based Single Sign-On (SSO) for ERP.
- • Site-to-Site VPN between Head Office FortiGate and AWS.
- • Rightsizing of application servers.
- • Reserved Instances and AWS Savings Plans.
- • Centralized monitoring, backup, and patch management.
High Level Architecture
Detailed Solution Architecture
Active Directory Migration
The complete Microsoft Active Directory environment was migrated from the on-premises data center to AWS. A Primary Domain Controller was deployed on Amazon EC2 Windows in Availability Zone-1 and an Additional Domain Controller in Availability Zone-2, with AD replication and integrated DNS delivering high availability through Multi-AZ deployment. The legacy on-premises AD was then retired, and all users across Head Office and branch offices now authenticate directly against the AWS-hosted Active Directory.
Windows File Server Migration
Approximately 4 TB of enterprise data was migrated to a Windows File Server hosted on Amazon EC2, with full preservation of NTFS permissions and folder-level Access Control Lists (ACLs). User access was validated after migration, ensuring business continuity while maintaining existing permissions and security policies alongside improved storage scalability.
ERP Integration
The ERP servers were domain-joined and integrated with Active Directory for centralized authentication, with SAML-based Single Sign-On (SSO) and role-based user access. Users can now securely access the ERP application using their Active Directory credentials.
Hybrid Network Connectivity
An AWS Site-to-Site VPN was established and integrated with the Head Office FortiGate firewall, providing secure communication over the existing MPLS network and private connectivity for branch offices. This allowed all corporate users to reach AWS-hosted applications without changing existing branch connectivity.
Optimization, Monitoring & Operations
Application servers were rightsized and covered by Reserved Instances and AWS Savings Plans to reduce long-term costs. Amazon CloudWatch, AWS Systems Manager patch management, and AWS Backup with an Amazon S3 repository delivered centralized monitoring, automated alerting, and backup, significantly reducing manual administrative effort.
Key AWS Services Used
The Benefits
Enterprise Identity Management
Complete AD migration to AWS with Multi-AZ high availability and centralized authentication for all corporate users.
Improved Business Continuity
Eliminated dependency on on-premises Active Directory with a highly available authentication tier and improved disaster recovery.
Secure File Services
Migrated ~4 TB of enterprise data with NTFS permissions preserved, improved storage scalability, and simplified administration.
Enhanced Security
Domain-integrated ERP, SAML-based Single Sign-On, secure Site-to-Site VPN, and centralized access management.
Operational Efficiency
Automated monitoring, patch management, and centralized backup reduced administrative effort across the estate.
Cost Optimization
Rightsized servers with Reserved Instances and AWS Savings Plans reduced long-term cloud infrastructure costs.
Modernizing Microsoft Workloads on AWS?
Zaptoz migrates Active Directory, file services, and enterprise applications to secure, highly available AWS architectures.