By: Peter Williams, Practice Leader - IT Infrastructure Mgmt., Bloor Research
Published: 17th July 2009
Copyright Bloor Research © 2009
Server virtualisation is well-established and is a great way to reduce the number of physical servers used by an organisation. Storage virtualisation ought to complement this—and eventually will do—by greatly reducing the number of storage arrays; used together they will make for a really agile business able to adapt quickly to changing needs.
What both also do is centralise the management, which is partly to simplify it and make it easier for one person to manage many servers or storage arrays; the physical equipment tends to become more centralised too—partly as an effect of removing ‘silos' of information held in various remote locations.
What is not always fully considered is the impact of virtualisation and centralisation on overall infrastructure performance. A first, and well-understood, reason is that when information is consolidated onto less physical devices the extra traffic per device means increased contention between applications and their need to access data—but virtualisation techniques can mitigate this by, for instance, wide striping the data and segmenting particular applications.
The second reason, often forgotten in cost calculations, is that branch offices that once had local systems that are now centralised, still need to access them; this pushes up the amount of network traffic and slows down access performance, and when WANs are involved, this pushes up telecom bills. Then there are things like consolidated backups perhaps sharing a single pipe instead of being spread. So servers or storage arrays may be drastically reduced in number but, as well as performance issues, the OPEX saving from consolidation is counterbalanced by higher communications charges.
The problem can be much worse than this. For instance, service level agreements (SLAs) and internal access performance criteria may be critically undermined by slow responses. It is well-documented that mission-critical applications are often ring-fenced outside of virtualisation because of performance worries. So what's to be done?
I am certainly not advocating abandoning virtualisation, but the most obvious solution does involve another investment. It is broadly described under the heading of ‘IT infrastructure optimisation'. This means speeding up any or all of: the applications, the networks (and especially the WAN) and storage access. It is not hard to see why this is a growing market niche. There are a few dedicated providers, notably Riverbed Technology, competing head to head with the likes of Cisco, Juniper and Bluecoat.
Riverbed is the market leader with over 6,000 customers. Mark Lewis, Riverbed's senior director of marketing and alliances in EMEA, sees networking, application and storage performance problems all converging. "For networking you need more bandwidth with latency the secret throughput killer," he said.
For storage it is data sprawl and islands of storage, backup and replication with compliance worries a side-effect; while some of these may be reduced by virtualisation, the sheer increase in the amount of stored data applies its own pressure.
Some of the applications most affected are those delivered via the web—including e-mail and FTP—as well as for instance, Lotus Notes, database access, FTP and ERP. When response times become too slow the applications can become unusable.
However, the biggest focus for me is centralisation (usually involving virtualisation) with remote access. For someone like me who follows storage and data protection closely, use of single instancing (SI) and data de-duplication (de-dupe) are hot topics. WAN optimisation involves the same idea—taken further. Lewis told me SI is applied across all connected sites including down to desktops, with duplicate data strings removed at very high granularity; along with other compression techniques this will reduce WAN traffic by 60–99%, he said.
It doesn't take a genius to work out how network performance can rocket by implementing such systems. Included amongst this is an ability to intercept some of the heavy overhead of TCP/IP as well.
There is a long list of potential major and minor infrastructure benefits that organisations could experience as a knock-on effect of the performance boosts from using some of these solutions, such as: reducing costs by avoiding new network bandwidth or deferring upgrades, more effective and flexible use of IT resources including improved worker collaboration, reduced risk and cost from service outages, much faster and lower cost remote replication, backup and disaster recovery (DR), reduced risk with data consolidated into secure sites, improved compliance with government and industry regulations, and so on and on.
A couple of years ago IDC did a survey looking at these types of potential savings when using Riverbed's Steelhead appliances and software; it concluded that the ROI period would average about 7.3 months and thereafter it would all be savings.
Obviously, each organisation's circumstances will differ, and the competitors in the market will continue to enhance their portfolios. The bottom line is: in these cash-strapped times, if you have any issues with your network (and not least if this is as a result of virtualising servers or storage), these types of solutions could remove a multitude of problems without breaking the bank.
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Published by: electronicdawn Ltd.