Whiptail tops the class with flash array plus SAN two-tier strategy

A school in West Yorkshire has implemented a Whiptail all-flash array that has reduced student login times on virtual desktops from 40 minutes to three minutes.

The school – St Wilfrid’s Catholic High School and Sixth Form College in Wakefield – opted for a two-tier storage strategy that places bulk data on a budget Huawei SAN while performance-sensitive virtual desktops are delivered from the £30,000 Whiptail flash array that can perform at up to 250,000 IOPS (input/output operations per second).

St Wilfrid’s, which has 1,800 students and 200 staff, runs around 1,000 desktops and laptops from 17 VMware virtual machines on three boxes plus two physical servers that deliver 110 virtual desktops using VMware View. It has already bought 200 more virtual desktop licences, with plans to deploy around 600 in total.

The school had been running an entirely physical environment, with 15 Dell PowerEdge servers and direct-attached storage, until last summer, when a thorough upgrade of IT delivery was carried out.

ICT manager Chris Slater, who had previous experience of delivering virtual machines using IBM servers and SAN with spinning disk, was set on a flash storage solution to speed performance.

Initially, Slater had concerns about Whiptail's relatively small capacity in terabyte terms, but, with the help of Newcastle-based reseller Aegis, developed a strategy of placing less performance-sensitive virtual server images and data on a budget Huawei SAN with SAS and Sata drives while virtual desktops are served from the Whiptail all-flash array.

“I was worried we’d only be getting 3TB of storage with Whiptail, but our virtual servers don’t need the IOPS like the virtual desktops do,” he said.

The school's Whiptail Accela flash array offers 3TB of capacity and is connected via 10Gbps Ethernet and iSCSI. The Huawei array uses 1Gbps Ethernet and has capacity of 9TB. There is no movement of data between the two storage tiers.

Slater estimated the school’s virtual desktops would need between 80 to 100 IOPS per user, with the aim being to grow to 600 users in the next couple of years. The Accela array comes in 2U format and uses MLC flash drives to provide up to 250,000 IOPS.

Slater was also approached by NetApp during the evaluation period, but had reservations about its ability to deliver the required I/O without prohibitively expensive amounts of spinning disk. Later in the process, NetApp offered an array with a flash component, but he still wasn’t convinced.

The key benefit of the Whiptail array for Slater is a noticeable reduction in login time. “When a class of students is logging on and pulling down a mandatory profile of around 4MB, it used to take up to 40 minutes, which is just not acceptable when there’s limited class time," he said. "Now that’s down to about three to four minutes from cold.”

The flash array market is changing quickly. Start-ups such as Whiptail and Violin Memory have achieved rapid prominence, and mainstream suppliers have rushed to buy or develop flash products under pressure from competitors and Wall Street.

Image: Jetta Productions