[net.arch] Uses of rms

rcb@rti-sel.UUCP (Random) (02/24/85)

When in a previous article I suggested that you bypass the operating system
file system, I meant it. If you really need efficiency, then why don't you
map your files to virtual memory. If the files are contiguous, then
your "file operations" will be as fast as memory paging.

(Isn't VMS wonderful. You can do anything you like. You just have to be
creative)

					Random
					Research Triangle Institute
					...!mcnc!rti-sel!rcb

guy@rlgvax.UUCP (Guy Harris) (02/25/85)

> When in a previous article I suggested that you bypass the operating system
> file system, I meant it. If you really need efficiency, then why don't you
> map your files to virtual memory. If the files are contiguous, then
> your "file operations" will be as fast as memory paging.

That doesn't bypass what really *should* be called the file system, namely
the code that turns references to block N of thus-and-such a file into
references to physical disk block M.  Some of the confusion here is being
caused by the fact that RMS and F11*ACP are being collectively referred to
as "the file system".  Well, 'taint so.  I'd call F11*ACP the file system.
It supports the creation of files, mapping of virtual blocks within a
file to physical blocks on a disk, and extension of files.  It maintains
the size of the file and various access/modification times.

Support of file structure is a separate function on RSX, VMS, and UNIX.
UNIX just makes this separation clearer than RSX/VMS does (or, at least,
UNIX documentation doesn't hide the raw interface to the file system as
well as RSX/VMS documentation does).

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy

jlg@lanl.ARPA (02/26/85)

> (Isn't VMS wonderful. You can do anything you like. You just have to be
> creative)
> 
> 					Random

A statement that can be applied to ANY system which is capable of simulating
a turing machine.  Hardly useful in comparing systems or hardware though.
By comparison with other systems VMS ISN'T wonderful.

J. Giles