Running virtual servers is now standard practice for many companies, but working out how to charge other business units for using them remains a far from easy task.
According to IDC, just under 20 percent of servers shipped in the fourth quarter of 2009 were virtualised.
"Customers are quickly moving beyond the core hypervisor and focusing on mobility, self-provisioning, and metering and chargeback capabilities," IDC VP of enterprise platforms Matt Eastwood suggested earlier this year.
However, unlike the competitive virtual machine technology market, chargeback approaches remain relatively primitive.
Victoria University in Melbourne is running a large VMware platform, with eight host servers and 130 virtual machines, almost 70 percent of which are used for production environments.
Those facilities are charged to individual faculties on a cost-recovery basis. As faculties have become accustomed to the virtualisation approach, the university has sought to make its charging models more flexible, offering the choice of monthly, yearly or five-yearly charging patterns.
"Now we're providing extreme flexibility," Victoria University virtualisation engineer Lloyd Williams told a meeting of the Melbourne VMware user group this week. "The big challenge with that is administration."
Currently, Victoria University relies on using an Outlook calendar to track utilisation, and having a staff member manually raise invoices for virtual machine users.
Ideally, that process would be automated. While VMware's management suite does include the ability to export usage reports, there's been relatively little work on automating that process via plug-ins to make chargeback easier, a situation Williams hopes will change in the future.
Any change will take place against a backdrop of increasing virtual machine use in businesses of all sizes.
By 2012, Gartner predicts that 58 million virtual machines will have been deployed globally, but the cost of those systems to business will be a major issues.
"Concerns over 'payback' for server virtualisation are rising as many organisations claim that total IT costs have increased rather than decreased since introducing x86 server virtualisation," the analyst firm noted in a 2009 report.
Gartner analyst David Coyle told iTnews in March that chargeback was proving "too complex" for most IT departments.