tiero - Fotolia
The University of South Florida Health System avoided storage problems that plague many virtual desktop infrastructure projects by following "basic math." That prompted its small IT team to use a Pure Storage FlashArray early on to head off performance issues.
The Tampa-based University of South Florida Health System (USF Health) comprises a number of USF schools, including medicine, public health, nursing, biomedical science, physical therapy and pharmacy. It also includes hundreds of doctors.
Systems administrator Richard Savage said USF Health has 800 virtual desktops with plans to expand to approximately 3,000. It uses VMware Horizon View for virtual desktops and Unidesk software as the management layer.
Savage said USF implemented a virtual desktop infrastructure (VDI) to improve doctors' access to electronic medical records. But even after zipping through a proof of concept with about 40 virtual desktops using spinning disk, he knew the project would require flash.
"We knew there were storage issues with VDI, but we didn't hit them," Savage said. "It was basic math -- a spinning disk SAN could only hit so many IOPS. There's a number of desktops you're going to hit that goes past your threshold."
Savage was already shopping for an all-flash array for primary database storage while running the VDI proof of concept. He said USF evaluated arrays from Pure Storage, EMC XtremIO, Violin Memory and Whiptail (now owned by Cisco), but Pure came out on top in every category. Those categories included price, performance and data reduction.
USF acquired two Pure FlashArrays early this year. It uses a 26 TB system for databases and an 8 TB version for VDI.
"We're almost entirely a VMware shop, and we were looking at moving our entire VM farm over to the FlashArray," Savage said.
Before switching to Pure, USF used an EMC VNX5600 with no flash for its VDI. Scalability became an issue. After acquiring Pure, USF repurposed the VNX for file storage.
"We started with a 6 TB [VNX] disk array and filled that up quickly and had to add another 6 TB," Savage said. "We saw that was not going to scale well."
That's where Pure's deduplication comes in. Savage said his VDI workload takes up only 2.5 TB on the Pure FlashArray.
Savage said meeting his eventual goal of 3,000 virtual desktops will likely require him to add another 8 TB array dedicated to VDI. "We're moving forward with VDI instead of desktop replacement," he said. "We will probably need to double the flash capacity we have now."
He said the biggest benefit of flash has been "massive performance gains on the back end. It was staggering. The biggest change was disk latency. We were seeing on average about 20 milliseconds of latency. With flash, it's sub-millisecond. The back-end jobs ran much faster and the user experience was much better. The feel of the application was much faster."
Savage said most of his users don't know they're using virtual desktops because there has been little performance hit. And VDI provides consistent information for doctors wherever they go.
Another benefit has been ease of management. "We were used to EMC's terrible process of provisioning storage pools and LUNs. The whole thing takes forever," Savage said. "For Pure, they had a guy on-site and the array was configured and we had storage presented to VMware within 30 minutes. We're a two-man shop for infrastructure and virtualization, so that was a huge selling point."
Complete guide to all-flash storage arrays
Gartner predicts Pure Storage to top all-flash array market