Executive Summary
A major State economic development agency attempted to migrate from Citrix to VMware Horizon. That project stalled. Over time, misconfigurations, unfinished work, and a lack of standards left both data centers in crisis. One site had a half working Horizon deployment that crashed constantly. The other site had an abandoned Horizon build and broken App Volumes packages. Citrix was still partially in use, and support staff were stuck in a loop of firefighting.
Z7 Solutions rebuilt one site from the ground up as a clean Horizon 8 reference architecture, then used that blueprint to repair the second site. The team retired Citrix, cleaned up years of technical debt in Active Directory and Group Policy, strengthened DR, and put governance around images and apps.
The end result was a stable, modern Horizon 8 environment that delivers faster logons, far fewer crashes, and significantly fewer support tickets. This became the launchpad for the cloud and containerization work that followed in Phase 2.
Customer
Organization
State economic development agency (State Entity)
Role
Z7 serves as the long term engineering and managed services partner for VDI and end user computing, starting in 2018.
Scope
Two primary data centers and thousands of users across multiple agencies and locations.
This engagement draws directly on Z7 core strengths in end user computing, cloud and virtualization, enterprise infrastructure, and cyber resilience.
Challenge
Years before Z7 arrived, the State Entity had launched a migration from Citrix to VMware Horizon. The project never truly completed. Instead, the environment slowly drifted into a state where both platforms coexisted and neither was healthy.
Site A
- Horizon deployment was unstable and crashed often.
- Users reported session drops, desktop freezes, and unpredictable behavior.
- vSAN and Dell hosts were overloaded, misconfigured, or both.
Site B
- The Horizon project had been abandoned before completion.
- App Volumes packages were incomplete, misaligned, or broken.
- There was no image lifecycle or consistent standard for configuration.
Environment wide
- Citrix remained partially in production. This meant duplicate tool sets and unnecessary licensing cost.
- App Volumes and DEM were used without clear rules, which caused random application failures.
- Active Directory was full of stale objects. Group policies were layered, conflicting, and hard to maintain.
- DR was limited to basic backups, with no real confidence in recovery.
- Help desk teams were handling a high volume of tickets related to logons, profiles, printing, and session stability.
Z7 Solution
Z7 delivered a structured remediation and standardization program that touched every layer of the environment, from the hypervisor up through the user profile and application stack.
1. Rebuild Site B As a Clean Horizon 8 Reference Architecture
Site B offered the best opportunity to start fresh. Z7 treated it as a greenfield reference design.
Key actions included:
- Deploying Horizon 8 components on supported, current versions.
- Correcting vSAN policy, datastore layout, and host configuration.
- Expanding Dell compute resources to remove oversubscription.
- Rebuilding App Volumes packaging and entitlements based on a clean model.
- Standardizing DEM usage for user and application settings.
- Hardening and documenting golden images with clear ownership and lifecycle.
Once completed, Site B represented how the entire environment should look and operate.
2. Repair and Align Site A To The New Standard
With a clean reference in place, Z7 turned to the more unstable site.
Key actions included:
- Cleaning vCenter, snapshots, and orphaned virtual machines.
- Fixing misaligned storage policies and cluster configurations.
- Aligning App Volumes strategy and DEM configuration with Site B.
- Stabilizing performance and removing recurring failure patterns.
Site A moved from being a constant source of trouble to a predictable environment that matched the standard created at Site B.
3. Full Retirement of Citrix
In parallel, Z7 removed the remaining Citrix footprint.
- Remaining Citrix hosted workloads were migrated into Horizon.
- Golden images were consolidated and standardized for Horizon pools.
- Citrix components, dependencies, and licensing were decommissioned.
This simplified operations, reduced cost, and made the environment easier for both the agency and Z7 to manage.
4. Active Directory and Group Policy Remediation
Many of the daily user issues were rooted in identity and policy. Z7 took a deep, methodical approach to AD and GPO cleanup.
- Rebuilt the OU design to match business and technical needs.
- Removed thousands of stale user and computer objects.
- Retired hundreds of obsolete or conflicting GPOs.
- Simplified and tuned logon policies to reduce overhead and improve reliability.
The result was a cleaner directory and a much more predictable logon experience.
5. Stronger DR and Operational Governance
Finally, Z7 focused on long term resilience and discipline.
- Implemented two site NetApp replication for key Horizon infrastructure and user data.
- Used cloud for backup and DR validation, without moving production desktops out of the data centers.
- Documented DR runbooks and tested failover patterns.
- Put formal governance around image lifecycle, app packaging, and change control.
- Enhanced monitoring and analytics to identify trends and recurring issues.
Measured Outcomes
Stability and User Experience
- Login times improved by about 48 to 60 percent after image tuning and GPO cleanup.
- Session crashes and disconnects dropped by more than 80 percent.
- Users reported far fewer interruptions, especially during peak hours.
Infrastructure Performance
- Overall VDI performance improved by an estimated 20 to 30 percent, largely due to vSAN remediation and added compute capacity.
- Both data centers now run a unified Horizon 8 architecture that is easier to support and scale.
Operational Efficiency
- Recurring VDI related tickets fell by roughly 40 percent, according to ticket system analytics.
- Support teams could shift more time from firefighting to planned maintenance and project work.
- Image, application, and policy ownership became clear and traceable.
Cost and Risk
- Citrix licensing and support expenses were fully removed.
- Outages and emergency fixes decreased, which reduced soft costs and stress on staff.
- Validated DR processes and cloud supported backups lowered operational risk.
Strategic Impact
Phase 1 transformed a fragmented, high risk combination of Citrix and Horizon into a single, modern, well governed Horizon 8 platform that runs entirely on premises. The agency now has a stable foundation for growth instead of a fragile mix of tools.
This work directly enabled Phase 2, where Z7 helped the agency move into Horizon Cloud on Azure, FSLogix profiles, Turbo containers, stronger endpoint security, and intelligence driven operations.