The London-headquartered company filters malware and viruses from client's web traffic as well as monitoring employee web usage patterns for customers ranging from SMEs to enterprises of more than 100,000 users in more than 50 countries.
"Traditionally we used DAS on four Dell servers and that had provided enough to us in terms of performance," says Walker. "But the sheer volume of data was likely to overtake that architecture before long and what we wanted was to go beyond DAS but without the management overhead and the expense of hiring a storage manager."
Scansafe eventually opted for two Pillar Axiom arrays with 20 terabytes total capacity using SATA drives. It chose that vendor despite being a customer of Dell, for whom EMC was its primary storage partner at the time. Walker considered EMC's CX-3 SAN but rejected it on cost grounds.
"We have a good relationship with Dell so it was natural to look at EMC storage at the time," says Walker. "But, chiefly we chose on price. Pillar was hungry for business and customer wins and we got them £5,000 to £10,000 below EMC for a similar product with better features."
Scansafe would not reveal the total amount invested but Pillar Axiom arrays are priced at around £77,000 each depending on exact configuration.
The key benefit to Scansafe is the scalability of the Pillar product. "We know we can double the size of the data warehouse in a week if we wanted to. It has an easy upgrade path that brings no disruption to users."
The Pillar Axiom provides disk array, controller and management system in modules known as Bricks, Slammers and Pilots respectively. A key selling point for the array – which is aimed at the mid-market – is that it comes largely preconfigured with storage managers able to select storage capacity, I/O rate, and priority of data allocation to disk using drop down menus.
Such ease of use was a key draw for Walker.
"We were really impressed with the ease of management and configuring it during set up," says Walker. "We're not storage experts and Pillar helped us with the install and gave us the SAN fabric. Setup was easy and so was setting alerts and maintenance. Rebuild times are good too."
With the Pillar product data can be tiered within the array, including by application, and given priority by the queuing engine in the Pilot.
Peter Williams, senior analyst with Bloor Research, says, "Pillar's architecture is very interesting, in that it writes data of higher importance to the outer edges of the disk. That part of the disk – because of the speed it moves at – effectively allows data to be more densely packed and more quickly accessed."
Such tiering within disks and 'application awareness' is not unique to Pillar, however, 3Par, Sun Storagetek and Overland claim similar capabilities.
Axiom users also have the option of choosing Fibre Channel or SATA disks. Scansafe chose the latter and has split its Oracle data between tiers on the drives. "We chose to go with just SATA on price," says Walker. "We knew we'd get as good performance as we had with the DAS set up and could upgrade to a Fibre Channel brick if we wanted to. Data from the OLTP environment goes to the higher-availability portions of the disks with that from the data warehouse going to the rest in a 40/60 split."
SATA disks are not as high in speed and I/O terms as Fibre Channel but they are cheaper. With the ability to carry out parallel writes to multiple drives it is possible to mimic the performance of Fibre Channel for less cost, says Dennis Szubert, senior analyst with Quocirca.
He says, "There are cost advantages as well as capacity advantages to using SATA disks and with techniques such as Pillar's you can get Fibre Channel performance too. There are also power and cooling advantages – the disks are bigger in capacity and use less power because they run more slowly."
Walker's only criticism of the Axiom is the lack of analytical capability in the product's management system.
He says, "One thing I'd really like to improve is the baseline monitoring and trend analysis. At the moment we have to do that using third party tools and would rather not have to spend extra time and money in that way."