Eliminating DaaS latency and operational burden at scale

NTT WEST, Inc., formerly NTT Business Solutions, provides system integration and ICT services primarily in the Kansai area of Japan. Its regional model combines locally based sales and systems engineering teams, with a growing focus on consolidating services in data centers.

One of NTT West’s key managed services is AQStage Virtual Desktop, a DaaS offering launched in 2011 with flexible plans to meet diverse customer needs. Backed by years of operational experience and high reliability, the service has grown to approximately 74,000 registered IDs as of 2026 and is expected to continue expanding.

As AQStage Virtual Desktop scaled, NTT West’s storage environment became a growing concern. Because the service is used primarily for day-to-day business operations, activity tends to concentrate around the start and end of the workday. Logoff was especially demanding: updated data had to be written back to storage and virtual machines had to be rebuilt as part of the logout process. When those activities overlapped, storage load spiked sharply.

The most serious issue was latency caused by logoff storms. Even though the environment had been designed with these usage patterns in mind, access sometimes became more concentrated than expected, pushing the existing storage beyond what it could reliably handle. Delays could exceed 100ms and, in some cases, affect customer operations. Because AQStage runs in a multi-tenant environment, the impact of one heavily affected workload could spill over into other customer environments sharing the same storage platform.

The operations burden was growing in other ways as well. To mitigate performance issues, the team repeatedly migrated affected environments to other storage systems to redistribute workloads. Those migrations were manual, time-consuming, and operationally complex because they involved large volumes of data and service-sensitive maintenance windows. At the same time, data reduction in the existing environment was insufficient, storage capacity remained under pressure, and recurring end-of-life refresh work placed additional strain on the operations team.

Around 2020, the company began planning a broader refresh of the DaaS infrastructure. The assessment concluded that the network and virtualisation layers did not need major changes, but the storage layer required a more fundamental redesign. NTT West identified four priorities for the new storage foundation: the performance needed to eliminate logoff-storm latency, stronger data reduction, easier day-to-day operations, and a long-term lifecycle model that would reduce the burden of recurring upgrades and refresh work.

After evaluating options, NTT West selected Everpure FlashArray as the storage foundation for AQStage Virtual Desktop. A proof of concept confirmed that FlashArray could deliver both the latency improvements and the data reduction benefits the team was looking for. Pure1 was another advantage, making the environment far easier to operate and reducing dependence on a small number of specialists.

Evergreen//Forever was equally important to the decision. Because the team manages a large number of storage systems, end-of-life events and version upgrades had become a recurring operational headache that required customer communications, scheduling, and planned maintenance. With Evergreen//Forever, NTT West gained a lifecycle model that avoids routine end-of-life disruption, allows controllers to be updated to the latest generation, and enables both software upgrades and hardware replacement without downtime. With Everpure engineers supporting the process, updates could be completed safely during business hours without affecting the environment or requiring advance notice to customers.

The results have been significant. After implementing FlashArray, maximum latency dropped from as much as 100ms to around 2ms, even during logoff storms. Data reduction exceeded expectations, reaching at least five times. Pure1 expanded the number of staff who could operate the storage environment from a small specialist group to about 10 people, eliminating dependence on a handful of experts. 

As Tatsuro Hiramatsu, Chief of the Managed Services Department at NTT West, put it, “FlashArray delivered effects beyond our expectations. Latency due to logoff storms has been improved, and we have achieved a data reduction rate of more than five times. The intuitive operability of Pure1 has eliminated our dependency on specific individuals, and Evergreen® has significantly reduced the burden of updates.”

The FlashArray environment has also scaled with the service. NTT West began deploying FlashArray around 2021 and expanded the environment as AQStage grew. By 2024, the company had introduced its tenth FlashArray and was operating an environment with several petabytes of effective capacity. Availability improved as well: where the previous storage platform experienced problems at least once a year, the FlashArray environment had seen zero such incidents. That shift also changed how the team thinks about the platform. 

As Kuniyuki Tanaka, Manager of the Managed Services Department at NTT West, explained, “FlashArray provides the high performance and stability required for DaaS. We no longer need to suspect storage issues, allowing us to focus on improving the quality of the service itself. I am confident that we can handle environments of tens of thousands of users with peace of mind.”

Looking ahead, NTT West expects AQStage Virtual Desktop to keep growing and sees the platform as a foundation for supporting even larger virtual desktop infrastructure environments across the broader NTT West Group. The company also wants to expand DaaS use cases for organisations operating highly confidential systems, including financial institutions and public sector organisations, where DaaS can help reduce dedicated terminal sprawl while supporting security approaches such as Zero Trust. In that context, NTT West is also interested in using Everpure FlashBlade® for network-attached storage and file service requirements in large-scale, multi-tenant virtual desktop environments.

By adopting FlashArray for AQStage Virtual Desktop, NTT West established a more stable, scalable storage foundation, reduced operational risk and specialist dependence, and removed much of the disruption associated with lifecycle maintenance. That has given the team room to focus on strengthening the service itself while supporting continued growth