The aging storage at Simsbury Public Schools caused an unacceptable lag for interactive whiteboards and streaming video, leading to end-user frustration and a migration from Dell EqualLogic to DDN.
Located in Simsbury, Conn., Simsbury Public Schools runs a full VDI environment using VMware with some 2,000 VMs for its teachers. Roughly five years ago, the VDI environment started to show some sluggishness as the demand for capacity outgrew what older storage arrays could manage.
Ray Vernacatola, network manager at Simsbury Public Schools, noticed lag on the VM side. Latency through VMware vCenter, a management utility for VMware environments, was an average of 50 milliseconds, but sometimes there were spikes as high as 900 ms, he said.
"When you're writing on a smartboard or if you're using any type of document camera, that's going to cause significant lag when you're writing or trying to show something under the camera," Vernacatola said.
Simsbury was using nine Dell EqualLogic SAN arrays, but they struggled to keep up with the read/write needs, and they lacked modern features such as data compression.
The school district graduated to a higher-performant storage system with DDN while shrinking its IT footprint and dropping latency from an average of 50 ms to under 1 ms.
The short search
One of Simsbury's requirements was for on-premises hardware.
"We're actually very against the cloud," Vernacatola said. "Where we are, there is a single point of failure for internet -- we have one fiber line going out. If that fiber is cut, and everything's in the cloud, I'm kind of hosed at school."
He started by looking at Dell EMC products first, as he was familiar with the products and had a relationship with the vendor. But, he added, he was never impressed with their performance.
He also put out word on a listserv that Simsbury was looking to replace its arrays, prompting another school district to contact Vernacatola about its array from Tegile -- formerly owned by Western Digital and now owned by DDN.
Ray VernacatolaNetwork manager, Simsbury Public Schools
When he compared Dell's offering with products offered by DDN, Vernacatola believed it would be a better fit for the school district, saying he could get better performance with necessary features such as data compression at a better price.
It was time to move the entire virtual environment to a new home.
Swapping arrays without headaches
Migrating from EqualLogic to DDN was straightforward, Vernacatola said. It took less than half an hour to set up the DDN arrays, have a LUN ready to go and have the "call home" automated support feature ready -- although the rack for the new arrays posed a problem of its own.
"The rack we had has uneven spaces between the screws," he said. "It probably took an hour to get the screws in and half that to get the array ready."
Still, in a week, Simsbury went from nine Dell EqualLogic arrays to two DDN arrays. The main array is the IntelliFlash T4700 all-flash array, which supports the district's primary systems, such as the VDI environment and main servers; it also creates snapshots for data backup and replicates them off site using Veeam. The footprint was reduced thanks to the data compression and deduplication features.
The school district eventually added a second array, the IntelliFlash T4200 hybrid array, for file servers.
"The hybrid does what it needs to do; it keeps the latency low for the file servers," he said. "But the all-flash array is just so fast. ... It's unreal in the difference, and it's made my job so much easier."
While the nine EqualLogic arrays are 4U with each taking up nearly the entire rack, the DDN setup is 8U. Thanks to data compression and deduplication features, both storage systems use the same amount of capacity, with DDN taking Simsbury from 75 TB of physical space to about 180 TB.
Saving on time and money
The two DDN arrays also cost less than the nine Dell EqualLogic arrays and come with better support, according to Vernacatola.
The built-in call home feature alerts Vernacatola when there is a hardware issue and can automatically order the necessary parts, which he then installs.
"Once I install it, I call home, the support guy, and he hits it from the back end and configures it," he said. "We're done."
An unforeseen advantage was installing the new arrays before COVID-19 caused schools to go to remote learning. With the old, slower storage, Simsbury would have struggled to use high-resolution cameras for remote learning, Vernacatola said.