[wmf]

This doesn't surprise me. Mainframes aren't just about never failing; they have a whole culture, including ops, around providing availability in ways that actually work.

[tjalfi]

I've also heard of teams that shut down the mainframe for an hour during a time change. It's an easy way to avoid application issues for a small amount of downtime.

[nubinetwork]

We used to do this on several hpux servers at $dayjob. However 95% of those servers have long since been decommissioned, and the remaining server didn't actually need it to begin with. (It was really anything that had an oddball database that needed it)

[TylerE]

If it runs Unix is isn't a mainframe.

Only half joking.

[nine_k]

I would say it's 90% not joking.

A mainframe has hardware different enough to require a different approach to the OS.

Of course a modern variant of System 390 happily runs tons of Linux VMs.

[pjmlp]

Starting by having systems programming languages that actually have proper strings, arrays and bounds checking.

[reverius42]

What are some of those languages? I'm curious to learn more.

[pjmlp]

Several PL/I dialects e.g. PL/S and PL.8, BLISS, Modula-2, ESPOL/NEWP for example.

Also Pascal and BASIC compilers with several extensions, e.g. VMS Pascal and VMS BASIC.

[fanf2]

BLISS is a typeless word-oriented language like BCPL, so I am surprised to see it in this list. Also I am amused to hear VAX/VMS described as a mainframe operating system.

[pjmlp]

Well, it had bounds checking.

I always call them mainframes, regardless if the name is micro or whatever is the pedantic nomenclature.

[fanf2]

Hmm, section 11.10 of http://wiki.parsec.com/openvms_archive/freewarev70/bliss/bls... says that the built-in vector type does not do bounds checking (tho there are examples illustrating how to define your own vector type that does check).

The string handling functions in chapter 20 require the programmer to pass around separate pointer and length arguments, which is not what I would call proper strings.