At a large Australian bank I contracted to about 10 years ago, it was suspected that they had upwards of 13,500 servers, including many mainframes. They had so

At a large Australian bank I contracted to about 10 years ago, it was suspected that they had upwards of 13,500 servers, including many mainframes. They had so many servers that there were more than a few just sitting uncollected and still packaged in the storage vault, abandoned several years ago when the project they were intended for was cancelled/put on hold etc. Nobody every claimed them. Another part of the problem is that in the past they invested in every platform under the sun that ran the financial applications they required, so there was a lot of legacy platforms that they couldn't yet rationalize away (AIX, Solaris etc). The other problem is that they are incredibly risk averse, and thus will build new platforms extremely slowly and only after immense testing will they cut over from the old platform to the new platform. They are typically averse to consolidation or rationalisation since the ongoing stability of the application is the most important factor to their business. A virtualization umbrella project that I was working on 10 years ago for this bank that covered several "core" platforms (AIX, VMware, Solaris, etc) is still under way as we speak, with many applications still to be migrated from old platform to the new one, despite the original "replacement" hardware now being obsoleted by the manufacturer already, according to those I know that still work there. I wonder if they'll ever finish.