Favorite operating systems query

[Paul Campbell]

As an ex-VMS kernel hacker and now Unix kernel hacker I still have a healthy
respect for VMS, it has many good features no Unix has how ever I have to
disagree with Larry on some points.

In article <452 at geowhiz.UUCP> larry at geowhiz.UUCP (Larry McVoy) writes:
>
>6) File system.  Why, oh, why, must the Unix file system be so fragile?  VMS
>   never loses your files.  And it's faster to boot up.  I have no idea what
>   the difference is in design but somebody ought to have a look & see what
>   could be done.
>
It is in reality almost as fragile as most Unix systems .... its just that the
system ALWAYS runs its own version of fsck when the system comes up after a
crash. It too looses files, trashes them and puts them in a "lost+found"
directory. VMS is more robust than Unix because it DOESNT have a block cache,
it writes through directly to disk. All buffering is done at the record level.

>8) Robustness.  VMS almost *never* crashes.  Unix crashes all the time.  You
>   damn near can't survive without source because you're always fixing 
>   something.  DEC has never handed out VMS src.  Unix is the ultimate example
>   of "the quick fix solution"; those solutions always turn out to be wrong
>   in the long run (trust me, this is the voice of experience talking. Sigh).
>
DEC will sell you source for about the same price as AT&T (commercial price
that is). If you have support you get uptodate source listings on fiche ...
beleive me after you have typed in all of the print symbiont (in assembler)
paying for source seems like a much better idea ......

>9) Related to (7), networking support.  Sockets are gross.  This isn't just
>   my opinion, ask the DoD what they think of sockets.  Remote filesystems,
>   remote devices, etc, are all being kludged in by every OEM in the field.
>   Have fun trying to make them all work together.  Design?  We don't need no
>   stinkin' design, we got 10,000 lines of code.
>
Here here, DECnet has a good user interface including particularly good support
for user servers and protection, a (relatively slow) distributed file system
comes with it. (I know I helped write a DECnet implementation ...)


Let me add my own pluses for VMS


+)	It has a far better user memory management interface than Unix, many
	things you can do under VMS are IMPOSSIBLE under Unix, unless you get
	into the kernel of course

+)	Much of the kernel is paged

And my one BIG minus about VMS

-)	Processes are far too expensive. Many things we take for granted under
	Unix are missing from or just too plain slow under VMS. The real
	problem is two-fold

	1)	VMS processes carry around too much context

	2)	The manner of creating a new process is such that transfering
		information from the old process is expensive. It happens
		automaticly in a Unix fork()



On the whole I prefer Unix but I do find myself missing many features of VMS ...
Thats all folks ......


		Paul Campbell
		..!ucbvax!unisoft!paul