It's about time. This is long overdue. The combination of the mainframe architecture's strengths with Linux's API/ecosystem could be pretty awesome. Anyone wondering why buy a mainframe should focus on these areas:<p>1. Reliability. Some have gone 30 years without downtime. Probably strongest selling point.<p>2. Channel I/O [1]: dedicated I/O processors plus scheduling that lead to high utilization (80-90+%) and throughput vs commodity servers. Second strongest point in mainframe's favor. I wish my desktop & servers had this rather than a knockoff.<p>3. Hardware partitioning that's more robust and rated at stronger security than most virtualization. Certain cutting-edge projects in INFOSEC are doing similar things at CPU and I/O layers. Mainframe's version, although not as cool, is decent and field-proven.<p>4. Built-in, proven software virtualization.<p>5. Hardware acceleration for some things such as databases and crypto.<p>6. IBM's ecosystem of apps, third-party providers, and services. This might matter to existing IBM customers.<p>So, those are a few advantages I hear from people who use mainframes. The z/OS-based mainframes have extra benefits in terms of software reliability, security through obscurity (obfuscation), and seemingly better use of both security (eg memory key) and functional (eg decimal) aspects of mainframe processors. The z/VM product has also been doing for decades what modern virtualization systems only recently do, even self-virtualizing since 70's.<p>So, there's some things to ponder. Whether it makes since financially vs other setups is a whole, different discussion. However, mainframes do retain strong, technical advantages over commodity architectures. They were doing cloud in one box before it was a thing. Their reliability is still unmatched with only VMS clusters and NonStop architecture getting close. So, it's a sensible choice for a business to spend extra $$$ to get high-throughput with no downtime and strong isolation of logical partitions.<p>Channel I/O [1]
<a href="https://en.wikipedia.org/wiki/I/O_channel" rel="nofollow">https://en.wikipedia.org/wiki/I/O_channel</a>