This article is part of our Essential Guide: Essential guide to disaster recovery and business continuity

Law firm gets EMC unified storage for effective disaster recovery

Surrey law firm TWM builds VMware virtualised infrastructure with EMC VNX unified storage to enable disaster recovery best practice

Surrey law firm TWM has completely revamped its server and storage infrastructure, moving to virtual servers and shared EMC storage in a move that provides best practice backup and disaster recovery, with the capability to restore files in minutes.

The project, which took nearly two years and cost £150,000 for the unified storage component, saw TWM move to a VMware virtual server environment. It had previously run a completely physical server estate, which meant a number of onerous challenges for the IT team, led by head of IT, Alan Barrett.

Barrett said: “We had to manage our physical servers very closely; updating drivers, patches, installing new software as well as the physical maintenance of the machines. We were looking for a solution to a disaster recovery situation that I was very uncomfortable with. If a site went down we were looking at days to get it back up again.

“Disaster recovery provision was based on prayer, with a lot of preparation.”

TWM has 170 staff at six sites in Surrey and south-east London and was running 36 Dell servers to support its mix of specialised IRIS legal sector software plus Microsoft Office, Exchange and SQL environments. It was backing these up using Symantec Backup Exec with agents on each physical server.

Since the project completed in 2012 it has four remaining physical servers – of which two are to be retired – that run 32 VMware virtual servers.

Backup is via Veeam, a specialist virtual server backup product, and has an EMC Data Domain DD160 data deduplication device as a target. This achieves up to 70% data deduplication ratios and users can restore files dating back to around a month old.

The Data Domain repository is not mirrored to another site, but all data is replicated between two EMC VNX 5300 unified storage devices that have replaced direct-attached storage (DAS) on the physical servers. The two EMC VNXs are sited at the Guildford head office and a secondary site at Epsom. Replication takes place every 15 minutes between them.

Another benefit is that TWM saved £15,000 on power and cooling costs by consolidating to fewer physical servers and shared storage.

TWM’s experience is typical of many SMEs currently undergoing a transition to virtual server environments. It is a switch that enables much simpler and cost-effective management of their server estates and also allows effective disaster recovery provision to be put in place, often for the first time.

Where previously disaster recovery meant keeping a costly and difficult-to-manage physical replica of the server and storage infrastructure, now servers are largely virtual and can be moved easily and run on any hardware. Tools such as VMware’s Site Recovery Manager – which TWM plans to implement – simplify failover and testing virtual machine disaster recovery.

Each EMC VNX has around 7TB of capacity on 15,000rpm SAS drives, split roughly equally between block and file data, and running Raid 5.

Unified storage merges block (SAN) and file access (NAS) storage into a single device and offers the advantage of managing both sets of protocols from one hardware console. It has become commonplace for storage suppliers to offer both types of access in a single product for the past few years.

The EMC VNX 5300 can also accommodate nearline-SAS as well as flash drives, but Barrett has settled for SAS only at this point. He said automated storage tiering – that matches data to appropriate drive type – is on the agenda for the future, but a flash storage tier is unlikely to figure in the plans.

Barrett said: “We’re not a transactional business. We provide high-quality legal services and speed is not an issue for us, so we’re not likely to need flash.”

Barrett rejected products from NetApp and Dell (EqualLogic) during the procurement process, largely on the grounds of cost and lack of attentive customer service.

“What pushed it towards EMC was the level of engagement we experienced. NetApp made us feel we weren’t important and Dell tried to push a product that just didn’t fit for us,” said Barrett.

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