[Info-vax] Request description of UFS for VMS person

[glen herrmannsfeldt]

Michael Moroney <moroney at world.std.spaamtrap.com> wrote:
 
> Yes, on VMS a file can exist without being in any directory.  By speaking
> the right magic to RMS a program can create a file not in any directory.
> It can be pre-deleted as well, see below.  The file exists because a
> header in INDEXF.SYS says it does.

I might have written this a few times before, but VMS 1.0 allowed

REN this.dir [this]

The directory then doesn't exist in any directory.  The blocks
are not removed from your quota.  I don't remember how I found
this out, probably accidentally.
 
> There is a bit in the file header that says the file has been deleted.
> It exists for valid files.  This may seem to be a contradiction, but the
> bit really means "delete this file when the last accessor closes this 
> file".  This bit being set causes ANALYZE/DISK to complain.

When did that appear in VMS.  It is standard for unix files
(and complicated NFS).
 
> What the familiar $ DELETE command really does is to open the file, set 
> the deleted file bit and close it.  99.9% of the time the DELETE command
> is the only thing accessing the file, so it is the last (only) accessor
> of it when DELETE closes the file.  It is here that the file system does
> the real deletion of the file (frees the header, used blocks etc).

(snip)

-- glen