The Pensions Trust is a leading multi-employer occupational pension fund for the Third Sector in the UK. Established over 60 years ago, The Pensions Trust has assets of more than £4.41 billion and serves over 150,000 employers and members.
The Pensions Trust was well into the process of rolling out a Virtual Desktop Infrastructure (VDI) with VMware’s View solution. However, this change in their computing architecture was hindered by a lack of 10 throughput with their existing hard-disk drive SAN. Users complained of slow responses during VMware View operations such as a Recompose or when anti-virus scanning took place.
“View was the elegant VDI solution that met our requirements. However, since virtualized desktop infrastructures inherently require high WRITE lOs, the major challenges we experienced with VDI were wrapped around storage performance. We decided to find a more VDI-friendly storage alternative,” said Darren Bull, Business Support Manager, The Pensions Trust.
“When looking at how we could increase performance with our existing SAN, the only option was to add way more storage capacity than we actually needed just to get the spindle count necessary to achieve the required
10 throughput. Estimates of VDI requirements that I have seen state that each XP virtual desktop requires 20-30 lOPS, with Windows 7 being higher still. Assuming a normal SAN disk delivers 150 lOPS, our requirements of 200 virtual desktops would require 26 traditional disks (15TB) @ 20 lOPS, 40 (24TB) if we assume 30 lOPS. Admittedly, some of these figures are up for discussion. What cannot be disputed is that we were going to require a lot of disk. Given the cost for a shelf of disks from our normal storage vendors, costs for this would have been unacceptable. Additionally, what a complete waste of disk space,” stated Mr. Bull.
The Pensions Trust decided to look for a more appropriate virtualization-friendly storage alternative. “There are a few solutions out there that attempt to solve this IO problem in different ways. Some storage vendors include a solid-state cache with their traditional disk arrays, however we found the cost of such systems to be out of our reach and in most cases they are only READ IO caches, wherein our VDI sessions need a high amount of WRITE IOs. Other vendors offer ‘man in the middle’ caching solutions that relieve the pressure on the underlying disk, however we felt that this added complexity to the solution that we could do without and again, from a cost standpoint, once we did our sums this type of solution didn’t really stack up for us,” noted Mr. Bull.
SEAMLESSLY DEPLOYED VMWARE VIEW ENVIRONMENT
“Our preference was always to implement a really fast SAN. Our preferred solution provider, Softcat, facilitated the evaluation of WHIPTAIL’s Virtual Desktop SAN appliance. Things that would typically be immediately noticeable to our VDI users, such as cloning operations occurring on the same LUN upon which they were working, boot storms, AV rollouts and so on disappeared immediately. We were able to watch an HD video on a VDI desktop whilst provisioning a desktop pool on the same LUN and rebooting about 50 others at the same time. Our viewing was uninterrupted and throughput disk latency was pretty much zero. If we had tried the same on our existing array we would have started to receive calls about slow performance immediately. Its performance on IOPS (especially WRITE IOPS) was dramatic. We were impressed and placed an order.”
Consolidate IT, a value–added distributor for WHIPTAIL in the UK and Europe, added: “With WHIPTAIL’s entirely flash-based architecture, customers now have a truly scalable centralized storage solution with all the known beneﬁts of a SAN. Years ago we introduced iSCSI as the storage protocol, now we introduce WHIPTAIL as the affordable SSD SAN,” said Jur Faber, CEO, Consolidate IT. “It’s perfect for VMware VDI and Database customers that simply do not accept the latency seen on standard mechanical storage, keeping the CPU and the customers waiting. The requirements that virtualization put on an enterprise’s storage infrastructure are heavy. WHIPTAIL
was born to handle this.”
“(Since WHIPTAIL) …users have stopped mentioning any slowness with our VMware View deployment. Helpdesk calls have reduced as a result. Most of the time our storage graphs are a flat line at zero latency. At its slowest it has always been much quicker than our old SAN on its best day. This implementation has enabled us to complete our VDI deployment with total conﬁdence that the underlying storage platform can handle anything we throw at it,” said Darren Bull, Business Support Manager, The Pensions Trust.
• VMware View virtual desktop infrastructure deployed successfully, ahead of project deadline
• Improved business flexibility
• Centralized infrastructure quickly realized return on investment and lowered total cost of ownership
• Increased user mobility and productivity