Council adds solid-state drive (SSD) tier to Compellent SAN for new HillingdonFirst residents' card

London Borough of Hillingdon installs solid-state drive (SSD) storage to its Compellent SAN to support Oracle databases in rollout of new HillingdonFirst residents' card system.

The London Borough of Hillingdon has implemented solid-state drive (SSD) technology in its Compellent storage-area network (SAN) to support the launch of a new HillingdonFirst residents' card system. The new SSD capacity supports the most-accessed parts of an Oracle database, and gives I/O performance up to 15 times faster than that of existing spinning disk.

The council has added three 146 GB STEC ZeusIOPS SSDs to support the card's rollout. The SSDs slot into the local authority's 30 TB Compellent SAN, which was implemented last year to form a new, faster tier above what had been a 20/80 Fibre Channel/SATA split.

We wanted razor-sharp access to that part of the database and the SSD gave that.
Roger Bearpark
assistant head of ICTLondon Borough of Hillingdon
"We had Fibre Channel and SATA drives as two tiers, and added in the SSD as tier 0 or tier 1 – we're not sure what to call it, but now we have three tiers: SSD, Fibre Channel and SATA," said Roger Bearpark, assistant head of ICT for the borough.

The key business benefit of the solid-state drive capacity identified by Bearpark is to speed up access to the residents' card database by 12 to 15 times. "It has lifted the whole performance of the application," Bearpark said, "and meant that we haven't been overwhelmed by people registering for the card. We wanted razor-sharp access to that part of the database and the SSD gave that."

The HillingdonFirst card gives the borough's 250,000 residents preferential rates at council parking facilities, access to libraries and the council's waste centre, plus discounts at local shops and businesses. Residents apply for the card online in a process supported by an Oracle database that requires fast access to its data to ensure processing isn't held up. Compellent's Data Progression SAN tiering software identifies the most active areas of the database and moves data between tiers. "The whole Oracle database now resides on all three tiers, but the most frequently accessed parts are moved up the stack automatically," Bearpark said.

The wider business benefit, he noted, is the ability to offer the business a more granular model of the possible data access IT can offer to support specific business propositions.

He also expects green storage benefits, which was a major reason Hillingdon Borough replaced a Sun StorageTek SAN with Compellent tiered FC/SATA arrays last year. "We're getting extra performance but also cutting energy use in that tier by a factor of 30," Bearpark said.

That implementation overcame limits on power supply and storage capacity by implementing the Compellent SAN to form a primary and secondary disaster recovery (DR) site shared with the local health trust. The project -- which was run in conjunction with a VMware server virtualisation initiative -- saved £50,000 annually on storage management staff costs and reduced the borough's carbon footprint by 20% per annum.

The borough implemented two 30 TB Compellent SANs, one at the main site and one located five miles away with a 20/80 Fibre Channel/SATA split with data moved between tiers by policies that take into account data age and type.

Bearpark said at the time that he was planning to evaluate the possibility of a three-tier setup using 15,000 rpm Fibre Channel drives and a 10/20/70 15K/10K/SATA split with the best-performing drives supporting Oracle databases. However, the availability of solid-state drives in the interim meant that adding extra spinning disk became less attractive as an option.

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