4. Storage Virtualization
As is the case with server virtualization, storage virtualization involves "abstracting" multiple storage devices into a single pool of storage, allowing administrators to move data among tiers as needed. Many experts view it as an enabling technology rather than a data reducer, per se, but others see a more direct connection to data reduction.
Actifio Inc.'s data management systems use virtualization to eliminate the need for multiple applications for functions such as backups and disaster recovery. Its appliances let customers choose service-level agreements governing the management of various data sets from a series of templates.
With this method, the proper management policies are then applied to a single copy of the data, defining where, for example, it is stored and how it is deduplicated during functions such as backup and replication. Company co-founder and CEO Ash Ashutosh claims that Actifio can cut storage needs 75 per cent to 90 per cent.
5. Thin provisioning
Thin provisioning means setting up an application server to use a certain amount of space on a drive, but not using that space until it is actually needed. As with policy-based storage, this technique doesn't cut the total data footprint but delays the need to buy more drives until absolutely necessary.
If storage needs increase rapidly, you must "react very, very quickly" to ensure that you have enough physical storage, says Allen. The more unpredictable your needs, the better measurement and management tools you need if you adopt thin provisioning. Schulz advises looking for products that identify both the data and applications users need to track, and that monitor not only space usage but read/write operations to prevent bottlenecks.
One of the vendors in this market is IBM, which has extended thin provisioning "into all our storage controllers," says Balog. HP, which provides thin provisioning on its P4000 SANs, is set to acquire 3Par, which guarantees that its Utility Storage product will reduce customers' storage needs by 50 per cent. Nexsan provides thin provisioning with its SATABeast arrays.
Before choosing a data reduction strategy, set policies to help make tough choices about when to pay for performance and when to save money by cutting your data footprint. Don't focus only on reduction ratios, Schulz says, but remember that you might get more savings with a lower reduction rate on a larger data set.
And don't be confused by vendor terminology. Compression, data deduplication, "change-only" backups and single instancing are all different ways of reducing redundant data. When in doubt, choose your storage reduction tools based on their business benefits and a detailed analysis of your data.
Which Dedupe Is Right for You?
There are deduplication systems to meet many different needs, depending the organization's reduction goals and system setup. Here's a sampling:
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