Mainframes tend to divide opinion amongst IT professionals. On one side there\u2019s the virtualisation-driven view that such machines are relics of a bygone technology era and should be replaced or migrated to virtual, cloud servers as soon as possible. This is already happening in areas such as SDDC (software-defined datacentres) that are increasingly taking on roles traditionally held by mainframes.\nOn the other side are the advocates and engineers who believe that these big, robust computers still have a role to play in today\u2019s enterprise. Who\u2019s right?\nIf the engineers on the front-line are any guide, there\u2019s little growth in demand for mainframe services. Newsgroups dedicated to mainframe engineers, such as IBM-MAIN@LISTSERV.UA.EDU (registration required), are peppered with requests for work referrals in amongst the technical Q&As. It appears to be getting harder for people in this line of business to find new roles, at least in some locations.\nHowever, market analysis doesn\u2019t necessarily support this anecdotal evidence. A modest growth rate over the next five years is predicted. In that period, the general consensus seems to be that more sales will be at the higher-performance end, rather than at the entry level where Windows\/Linux servers are increasingly competitive.\nIt\u2019s worth bearing in mind that sales of new machines don\u2019t tell us how many organisations are still using the old ones. The market may not be growing by much, if at all, but there\u2019s life in it yet. There\u2019s also a belligerent confidence on the part of those still involved, coupled with a large dose of cynicism about potential replacements.\nDave Wade, a mainframe engineer since 1976 who recently worked on migration of physical servers to VMware environments, is bullish about mainframes. \u201cI don\u2019t think anyone techy involved in mainframes can see any point in moving off them,\u201d he says. \u201cManagers think they can save money by getting rid of mainframes because PCs are cheap. In reality, delivering scalable enterprise software on any platform is challenging and expensive as it needs new design, capacity planning, etc.\u201d\nAl Kossow, curator at the Computer History Museum, told me, \u201cWhatever you replace [a mainframe] with will be obsolete in 10 years, and won\u2019t be supported as well because that\u2019s the way the economy works now.\u201d\nWhen individual mainframes are retired, it\u2019s for any one of a number of reasons, including companies going out of business or enterprise-wide replacement of core IT systems. But it\u2019s the migration of mainframe operations to virtualised systems that\u2019s currently in favour. Security fear is one factor driving this, with no shortage of analysis and comment (try a search for \u201cmainframe security\u201d) pointing out the risks of using mainframe systems. Another issue is the retirement of the people who know how to program these systems properly, though judging from the newsgroups there are still plenty of skilled engineers available.\nIntuitively it makes sense to migrate from an unwieldy chunk of metal to a scalable, secure, virtualised platform. However, just because a concept is intuitively appealing doesn\u2019t make it logically or commercially sound. \u201cVendors want to push you into cloud subscriptions because that helps with vendor lock-in. Companies like it because they can outsource their hardware and eliminate support people,\u201d says Kossow. \u201c[But they] then have people twiddling their thumbs (or lose business) when the network goes down.\u201d\nIn addition, the security fears may be overblown. An IT manager for a major APAC banking organisation, who understandably wishes to remain anonymous, told me that the bank\u2019s support time and costs for mainframes are dwarfed by those of newer systems, especially when it comes to security. \u201cWe had some dumb policies in place, based on the idea that a secure perimeter meant our internal systems were invulnerable to malware. When I finally managed to force through a proper audit, we found that every single workstation was infected. No such problems with the mainframes, which plodded on regardless just doing their job.\u201d\nTo make matters more complex, any transition process is fraught with risk. Al Kossow again: \u201cThe two biggest problems with migration and retirement are that companies count on a few people to know their business process and how that was implemented by computer, and feature-creep\/requirements change in the system design and replacement processes.\u201d\nWade is more blunt about migration problems. \u201cAs a manager, do a simple risk analysis as to how likely it is you can get enough code moved to get your bonus and get out before it falls down in a nasty heap because the mainframe guys have shafted you and\/or you didn\u2019t put enough resources in to build the scalable platform,\u201d he says. \u201cThen do a Google search for failed mainframe migrations and re-calculate the risk...\u201d\nThere seems to be a generational divide when it comes to mainframe technology. In researching this article I contacted the director of the Vintage Computer Federation, Evan Koblentz. He told me, \u201cYounger employees assume anything from before their generation must be obsolete.\u201d He went on to liken mainframes to Cobol: \u201cBunch of non-technical technology reporters kept writing in faux shock that important organisations \u2018still\u2019 use Cobol. Damn it, those companies use Cobol because it\u2019s good not because they are stupid.\u201d He believes the same applies to mainframes, and it\u2019s clear that he\u2019s not alone.\nThere may even be a temporary growth in mainframe popularity underway. As Koblentz says, \u201cmainframes are having a resurgence because of big data: regular servers can\u2019t keep up.\u201d This may be a short-lived blip rather than sustained growth. \u201cThe resurgence may end in a few years if NMVe-based servers become common,\u201d Koblentz tells me.\nEven so, big iron obviously still has a role to play in today\u2019s enterprise IT environment. To misquote Mark Twain, reports of mainframes\u2019 death appear greatly exaggerated.