Sounds like a good idea, but it had little value in practice (for me). Since disk space came at a premium back then, it led to constant manual/auto purging.

It's so long since I was using VMS, but one thing I do remember is the constant purging. It was necessary.

There are areas (CAD) where it made a lot of sense.

You could set the number of versions to keep on a per directory level.

No one told me then and keep on purging it. Any command to do that just for old time sake?

for a single file (or directory, the syntax is the same). I've forgotten how much I love the HELP command on DEC systems. Having the old versions there saved my bacon more than once back in my student days.

  SET
  
    FILE
  
      /VERSION_LIMIT
  
            /VERSION_LIMIT[=n]
  
         Specifies the maximum number of versions for the specified file.
  
         If you do not specify a version limit, a value of 0 is used,
         indicating that the number of versions of a file is limited only
         to the Files-11 architectural limit of 32,767. When you exceed
         that limit, the earliest version of the file is deleted from
         the directory without notification to the user. For example, if
         you set the version limit to three when there are already five
         versions of that file in your directory, there will continue to
         be five versions of the file unless you specifically delete some
         or purge the directory. Once the number of versions is equal
         to or less than the current version limit, the version limit is
         maintained.

Same, got it emulating an old tape recovery image of a vax 3100 m76.

Ugh... I can't get it to build under Termux on my phone.... I need gcc, and don't know how to get it installed. Walking around with a running VMS system in my pocket would be soooo cool. ;-)

My netbook has plenty of horsepower to run it... the phone should too.

Update.... I've got it running... and can telnet into the VAX/VMS 7.2 system in my pocket. ;-)