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- Path: sparky!uunet!gatech!concert!ais.com!bruce
- From: bruce@ais.com (Bruce C. Wright)
- Newsgroups: comp.os.vms
- Subject: Re: How Open is Open VMS?
- Message-ID: <1993Jan1.133650.5924@ais.com>
- Date: 1 Jan 93 13:36:50 GMT
- References: <1992Dec31.190236.29454@zooid.guild.org> <1992Dec31.164508.1051@cmkrnl.com>
- Organization: Applied Information Systems, Chapel Hill, NC
- Lines: 43
-
- In article <1992Dec31.164508.1051@cmkrnl.com>, jeh@cmkrnl.com writes:
- > In article <1992Dec31.190236.29454@zooid.guild.org>, Mark Kovarski <kovarski@zooid.guild.org> writes:
- >>
- >> Could someone tell me how "open" Open VMS really is. Is it so open that
- >> someone can obtain the source codes, or is it another proprietary operating
- >> system with the word "Open" attached to it? Thanks.
- >
- > VMS is just as proprietary as, for example, SCO Unix, SunOS, HP-UX, etc.
-
- Just about the only really `open' system is GNU. IMHO, most OS vendors
- who use the term are really engaging in FUD, including DEC's `Open' VMS
- and Sun's absurd `Open' posturing.
-
- For what it's worth, one of the products that AIS sells runs on multiple
- platforms: VMS and various flavors of Unix. Although VMS != Unix and
- there have been certain problems keeping things coordinated between the
- two systems, by far the _worst_ problems have been with certain Unix
- systems, both because of compiler problems and because of OS problems.
- I don't think I'm at liberty to discuss the details so please don't ask,
- but the vendors I'm thinking about are very well-known Unix vendors.
-
- > [...]
- >
- > It is generally not necessary, though, to recompile nor even to relink any
- > part of VMS in order to add to it or change it. In particular, device
- > drivers can be added to a live running system. You can even replace an
- > old version of a driver with a newer one on a live system.
-
- You can often replace an old driver with a new driver, but if any of the
- driver's data structures change (UCB changes, for example), you may need
- to make special provisions for this in the driver's code. For example,
- VMS will not automatically unlink and reallocate a UCB if the UCB length
- changes for the new driver. If you reload a driver that has had that
- kind of change, and which doesn't provide for reallocating the system
- data structures itself (a complex task in the general case: it may have
- to know what the format of every data structure it's ever used is so that
- it can properly unlink everything), a system crash is _highly_ likely.
-
- I'm sure Jamie knows this, and that his comment was an offhand comment
- related to the `open systems' nonsense, but if anyone else is doing this
- they should be aware of the possibilities for trouble.
-
- Bruce C. Wright
-