Zombie servers – both physical and virtual that use power but do nothing – are collectively costing organisations billions in CAPEX and OPEX. In light of this, The Green Grid suggests that organisations should develop a strong business case to gain the buy-in and resources needed to execute a zombie hunt.
Metrics such as The Green Grid’s Power Usage Effectiveness (PUE) provide an indication of a data centre’s efficiency in terms of infrastructure upstream of the IT equipment, such as cooling, uninterrupted power supplies (UPS), and lighting. While great progress has been made in reducing industry average PUE through education and adoption of best practices, if this more efficient infrastructure is powering and cooling servers that are very inefficient due to low utilisation, all this good work is only addressing a fraction of the problem, leaving large energy and cost inefficiencies untouched. A key culprit that drives down server fleet utilisation is the existence of zombie servers.
However, Roel Castelein, EMEA Marketing Chair for The Green Grid, argues that with the right tools, organisational understanding, methodology, and management processes, ‘zombie hunts’ can be executed quickly and with little risk.
He explains: “Promised costs savings and more productive and secure infrastructure are compelling motivations to slay zombie servers residing throughout data centres. However, this is not a new revelation. Earlier studies have exposed the prevalence of zombie servers not doing any useful work for months and years, and the significant cost associated with them. Yet organisations often complacently assume, usually without evidence, that there aren't many of these servers, and that their infrastructure is the epitome of productivity and efficiency.
“However, today’s more sophisticated asset management and resource optimisation solutions confirm the persistence and pervasiveness of zombies (typically consisting of 20 to 30 per cent of total servers in a data centre). In fact, even virtualisation environments have succumbed, with similar level of use, offsetting the productivity and cost reduction benefits of virtual machines (VMs). Fortunately, asset management technologies and tools have evolved to significantly facilitate not only the ‘zombie hunt’, but also the ongoing control and suppression of zombie populations.
“To suppress zombie servers for good we recommend that organisations implement the following approach. Firstly, identify the key stakeholders who will need to be engaged to provide resources and support. Secondly, review the tools available to facilitate a successful hunt. Thirdly, detail how to prepare a zombie detection plan and deal with them once they have been found. Lastly, lay the groundwork for a compute-asset management programme that will prevent zombies from appearing again.
“Ultimately, a successful hunt that’s coupled with a comprehensive and well-executed management programme will ensure that organisations are able to reap the significant and perpetual benefits of riding their infrastructure from zombies forever,” Roel concludes.
