| > What kind of demand do you think there is for a Linux-only mainframe? I think the answer really depends on IBM. Technically speaking, the hardware is rock-solid. There are no single points of failure in mainframe systems. But there are still some obscurities with the platform. There's a lot of packages you'd expect to be available in your s390x distribution of RedHat or SUSE that missing. And that's probably because the average open-source developer/maintainer doesn't have the means to develop/test on a mainframe. IBM needs to realize they have an open operating system on a closed platform and the two don't mix. They are taking steps in the right direction, but time will tell if they get there. And they have to prove they can compete with the x86 guys on price. > My limited understanding is that most mainframe customers are locked-in, e.g. they have legacy COBOL code running their ledger system and the expense to switch off of it is simply prohibitive. That plus the fact that the system is reliable, low-maintenance, etc. preserves the status quo, despite the fact that if you were to write the same applications today, you'd choose a newer platform because it would be more cost-effective. You are mostly on track there. Mainframes haven't died because of many of the reasons you listed above. But I'd have to disagree with last statement about choosing a "newer" platform. Mainframe hardware is modern hardware, in the sense they are updated every one to two years. Mainframe operating systems are modern operating systems. They also get updated every one to two years. If you look at every industry that has been around for more than 30 years, almost all of their mission critical workloads are done on System z. Cheaper isn't cheaper when you have downtime. But for some workloads, you are right: companies are only on mainframes because migrating to a different platform would be too costly. Even over 10, 15, 20 years. |