Clark Construction Migrates to AWS in One Week

  • Migration

The company completed an AWS migration within a week — without anyone noticing except for IT

Aiming to eliminate the time that its IT staff spent maintaining on-site infrastructure, Clark Construction wanted to migrate its applications and data to the cloud. Using CloudEndure Migration, the company moved everything to AWS without a hitch. The migration lasted less than a week and went so smoothly that the employees outside of the IT department never knew the company’s servers had migrated.


With headquarters in Bethesda, Maryland, and 10 other regional offices around the U.S., Clark Construction is one of the largest privately-held general contractors in the country, with more than $4 billion in annual revenue. For more than a century, the company has completed intricate interior renovations and some of the most complex civil operations in the U.S. Clark Construction takes pride in providing world-class service to its clients and in its ability to handle projects of all sizes and levels of complexity.

The Challenge

Clark Construction set a goal to shift the applications and data from its 50 servers running in its data center to AWS by the end of the year. With limited staff, the company’s IT department wanted to spend more time on business operations and less time operating a data center and hardware facilities. Bob Gelety, the Director of Network Engineering at Clark Construction, and his staff chose AWS because of its strong reputation. They needed a migration tool that could migrate their data and applications running on VMware architecture, and which would also ensure they met their time constraints for the project.

After three migration tests with another tool, it was obvious they needed a different solution. Clark Construction had a small window in which to migrate: downtime was limited to an 8-hour period — once every other month. Using the tool they were testing, it would have taken days of downtime for Gelety and his two network administrators to migrate a terabyte of file-sharing applications and data into AWS, a luxury they didn’t have. Gelety was also faced with another hurdle: having six Oracle-based financial legacy workloads, which their vendor claimed could not be migrated to the cloud without being rebuilt.

The Solution

AWS recommended CloudEndure Migration to Gelety’s team. Clark Construction wanted its migration to be handled by a proven enterprise-grade solution that could be deployed quickly, affordably, and without system disruption. Within a few hours of testing, Gelety and his staff had successfully migrated a couple of servers and immediately recognized that they could migrate all of their servers without complication or the limitations experienced with the other tool — and with the speed that was needed to accommodate the 8-hour downtime window.

Preparation was important. Gelety and his team had methodically planned the migration project and wanted to ensure that every bit of data could be replicated before going live on AWS. CloudEndure Migration’s support staff worked closely with Clark Construction’s IT staff, constantly checking the data’s continuous replication status before the planned cutover.


CloudEndure Migration successfully replicated Clark Construction’s 26 applications. This process included the initial synchronization of existing server data and the continuous replication of any newly-written server data in real time. It was completed within several days.

At this point, Gelety and his team were able to test the most up-to-date state of their servers on AWS at a moment’s notice, as many times as needed, and without any disruption to their source applications. This ensured that when the golden 8-hour cutover window arrived, they knew exactly what to do, and could complete the cutover in minutes. When the time came, Gelety and his team simply spun up the most up-to-date state of their servers in AWS, and shut off their in-house servers.

The cutover period lasted minutes, and Gelety and his team knew it went smoothly since none of Clark Construction’s 3,000 IT infrastructure end users noticed that the servers had moved, overnight, to AWS. In addition, CloudEndure Migration’s capability to successfully migrate the six legacy financial applications to AWS without a hiccup — something the vendor had said couldn’t be done — was icing on the cake.

“I wanted to be able to say, ‘At midnight on Friday night… I want to turn on these servers on Amazon and turn them off in our old environment,’” Gelety said of CloudEndure Migration. CloudEndure Migration enabled Gelety and his staff to migrate to AWS without fanfare. “We treat no news as good news,” he added.

With the migration successful and Clark Construction’s business continuity objectives reached, Gelety now plans to further leverage CloudEndure Migration technology by using CloudEndure Disaster Recovery to maintain business continuity.

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