Is there any reason to use VMS today other than for existing applications that cannot be migrated? I've heard its reliability is legendary, but I've never tried it myself. The 1 year licensed VM seems excessively annoying. Is it just old and esoteric, or does it still have practical use? At least with Linux, multiple vendors release and support distros and it is mainstream, whereas with VMS, you'd be stuck with VSI.

In modern times, we have taken the everything breaks all the time, make redundancy and failover cheap/free approach.

VMS(and the hardware it runs on) takes the opposite approach. Keep everything alive forever, even with hardware failures.

So the VMS machines of the day had dual redundant everything, including interconnected memory across machines and SCSI interconnects and everything you could think of was redundant.

VMS clusters could be configured in a hot/hot standby situation, where 2 identical cabinets full of redundant hardware could failover during an instruction and keep going. You can't do that with the modern approach. The documentation was an entire wall of office bookcase almost clear full of books. There was a lot of documentation.

These days, nothing is redundant inside the box level usually, we instead duplicate the boxes and make them cheap sheep, a dime a dozen.

Which approach is better? That's a great question. I'm not aware of any academic exercises on the topic.

All that said, most people don't need decade long uptimes. Even the big clouds don't bother with trying to get to decade long uptimes, as they regularly have outages.

I was actually surprised to see that there's been a release in the last 12 months - I had thought it was dead.

I used it extensively in the late 90's early 00's and really liked it. As a newb sysadmin at the time, the built-in versioning on the fs saved me from more than one self-inflicted fsck up.

I can't imagine there would be any green-field deployments in the last 10 years or so - I'm guessing it's just supporting legacy environments.

It's fun for hobbyists! The first multi-user system I used happened to be a VAX/VMS system, so it brings me back to my youth. I have a VAX running in simh, complete with compilers. The release, VMS 7.3, is almost 25 years old.

There is a pretty good amount of operation-critical stuff like power plants (especially nuclear), radars, traffic management and various finance/insurance/airline services that operate on VMS afaik. Something about very reliable cluster-native operations, or so it would seem. 90's cloud-native.

> Is there any reason to use VMS today other than for existing applications that cannot be migrated?

No, there is no reason to do a greenfield VMS deployment and hasn't been for a long time.

> I've heard its reliability is legendary, but I've never tried it myself.

I've heard the same things but I am doubtful as to their veracity in a modern context. Those claims sound like they come from an era where VMS was still a cutting-edge and competitive product. I'm sure VMS on vaxclusters had impressive reliability in the 1980s, but I doubt it's anything special today. If you look at the companies and institutions that need performance and high reliability today (e.g. Hyperscaler companies or the TOP500) they are all using the same thing: Linux on clusters of x86-64 machines.

I used it a bit at University - most notably it had an Occam system on it that wasn't available on the Sun workstations.

I'm curious about running a VMS system although the admin side looks a bit daunting. The thing I'd really like to do is run X-Windows on an emulator on my home lab, just to see it run.

That is the kind of comment that a well run bulletin board would moderate. Then again, there are probably not enough VMS systems people left to really have an r-war (short of architecture war).

VMS' key feature over Unix is consistency and beyond that it is being interrupt driven at all levels (no wasted cycled polling except for code ported over using POSIX interfaces). VMS was killed by a confluence of business issues, not because it was obsolete or inefficient.

No. Most of the good stuff was lifted into Windows NT decades ago. The rest has been far surpassed over the same time period by Linux and others. A few cool things probably fell into the cracks, but that's common in the industry.

It's interesting in a "what if/parallel universe" kind of way, but I certainly wouldn't touch it for anything new with that licensing.

I had a job at a place in college, back 1997–2000, that was run by a big DEC Alpha server running VMS. VMS was dying then.

I was just a lowly kid programmer working on a side project, so I can't tell you whether it's still uniquely good at something to justify its usage today. It worked. But it was weird and arcane (not that Unix isn't, but Unix won) and using it today for a new project would come with a lot of friction.