Sorting the wheat from the chaff
Using ILM to increase Data Centre performance

With growing pressures on the Data Centre to support organisations as they fight to remain competitive, and deliver on an ever-growing list of security, compliance, and environmental requirements, the role of information lifecycle management (ILM) has never been more important.

At Logicalis, we think of ILM as a comprehensive approach to managing the flow of an information system's data and associated metadata, from creation and initial storage, to the time when it becomes obsolete, and is, ultimately, deleted.

There's certainly plenty to discuss about the fact that, in reality, so little data ever actually gets deleted, but nonetheless ILM represents a fundamental approach to optimise the performance of the Data Centre. However, it needs to be managed carefully to ensure that the benefit is clearly delivered to the Data Centre and organisation, not just in efficiency savings, but in better and more appropriate application performance.

The conventional view is that data that is mission-critical today may be of little value in a month, and almost worthless in a year. In today's world, that is far too simplistic a view. Just because a piece of data is old, it doesn't mean that it is not vital for business planning, or required as evidence of compliance. A key feature of ILM is that within that approach there are a series of policies, procedures, practices and tools, that are implemented. These are used to align the business value of information with the most appropriate and cost effective infrastructure, and ensure that it is, in turn, aligned with business processes, through management of policies and service levels. This is why it's a strategy for getting the best out of both the Data Centre and the applications it supports, and shouldn't be confused with just a collection of technologies, as it so often has been in the past.

That being so, unlike earlier approaches to data storage management - which still pervade in many organisations - ILM involves all aspects of dealing with data, starting with user practices, rather than just automating storage procedures, as for example, does hierarchical storage management. Also, in contrast to older systems, ILM enables more complex criteria for storage management than simply data, age, and frequency of access, and that's one of its key values.

ILM then increases the performance of the Data Centre and the organisation it serves, by automating the processes involved. Typically, of organising data into separate tiers according to specified policies, and automating data migration from one tier to another based on those criteria.

This amounts to four levels. As you'd expect, newer data, and data that must be accessed more frequently, tends to be stored on faster, expensive and more energy consuming disk-based media such as fibre channel disk systems. Less critical data is stored on cheaper, but slower serial technology architecture (SATA) disks, and often tape-based devices, for data that needs to be retained but is unlikely to be accessed again. Lastly, offline tape can be placed in a secure facility - probably offsite - and reintroduced to the tape library if it needs to be recalled. This approach can be a basis for the efficient selection of devices and particularly their virtualisation, a route to further savings and efficiencies.

Delivering value from data
Clearly, to deliver value, the ILM approach must recognise that the importance of any data does not rely solely on its age, or how often it's accessed. This is particularly true of compliance where the issue may be how quickly any one piece of data can be located at any one time. It's also true that faced with corporate governance regulations, it is becoming increasingly important to protect even seemingly worthless data from accidental destruction or loss.

That means that to be effective, ILM users must specify different policies for data that declines in value at different rates, but particularly that which retains its value throughout its life span. That having been established, a good path management application, either as a component of ILM software or working in conjunction with it, should make it possible to retrieve any data stored by keeping track of where everything is in the storage cycle.

This is where ILM differs from data lifecycle management (DLM). DLM deals only with general attributes of files, such as their type, size, and age. ILM recognises and deals with more complex capabilities. For example, whereas a DLM product would allow you to search stored data for a certain file type of a certain age, an ILM product would let you search various types of stored files, for instances of a specific piece of data, such as a customer number.

Undoubtedly in a Data Centre, where terabytes of data have to be backed up each day; where thousands of often concurrent users have to be supported, and where vital compliance information has to identified and retrieved at the drop of a hat, implementing an ILM strategy can deliver a huge saving in hardware and maintenance costs - not to mention on power consumption. A good ILM strategy can also put paid to the instinctive desire to store all application data on the same high-end disk arrays, and instead spread the appropriate data on to more cost-effective second, third and fourth tier devices.

This means carefully considering which application belongs to which tier. This may involve thinking outside the Data Centre and having ICT staff talk to business managers and users, about what they expect in terms of IT reliability, performance, and recoverability. This can inform your strategy across the whole of the enterprise, and allow you to resist the temptation of purchasing the latest bit of kit that `would do the job`. In this respect, you always need a functional specification of the problem you're trying to solve. The thinking horse should come before the technology cart.  

Getting ILM right from the beginning
So, in any ILM implementation, you have to start with project scoping and business analysis. Identifying the sort of data that is being stored in the Data Centre, and classifing it in terms of what tier the data belongs, or what level or service it deserves, is a key differentiator in resolving the pressure on today's Data Centre.

Then comes the definition of policies about the way the data should be handled. These are the most vital of decisions as they will dictate just how much equipment you need, or more commonly don't need, but still have. Again, this is often about how long emails or transactional data should be kept available from top tier storage. Only then should you think about the software that might make it happen, and lastly the devices on which it, and the data, is going to sit.

What can be covered in a paragraph as an idea can be a huge task in reality. The analysis and classification of large amounts of unstructured data can be a daunting, if worthwhile, task. Unlike database or semi-structured email data, the value of file-level data is not simple to assess from its meta-data. Its contents may need to be examined, and that may involve ICT staff and business users talking to each other about what they think the data is really worth.

And that is something you must do before you are consider allocating applications in lower tiers. The one critical issue here is application performance - ultimately the thing which users care about most.

It is a very worthwhile journey to take as part of creating a leading-edge Data Centre, with more and more UK businesses starting to embrace the ILM process as part of their strategy and infrastructure. The Information and Lifecycle Management Survey 2006 conducted by market analyst group Quocirca, found that, in the last twelve months, UK businesses have moved from the planning and implementation stages, to fully incorporating ILM strategies as a core part of their infrastructure, with positive effects on the businesses they serve.

In particular, the report concludes that businesses that are confident that they can respond adequately to changing regulations, as and when they are imposed, are less likely to have to undergo internal restructuring in response. This leaves them freer to focus on their core business activities, such as searching for and exploiting new markets and pursuing mergers and acquisitions.

 

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