[NTLUG:Discuss] VMWare

[Chris Cox]

Well put Chris.  Another way to look at this is that VMWare gets contention
much in the same was as you cannot have more than filesystem mounted
at the same time on a mount point in Linux.

Christopher Browne wrote:
> 
> On Fri, 26 Nov 1999 22:31:07 CST, the world broke into rejoicing as
> Richard Cobbe <cobbe at directlink.net>  said:
> > Chris Cox wrote on 11-26-1999:
> > > VMWare can directly access your CDROM, parallel and serial devices...
> > > BUT...remember, that if VMWare is using them, then Linux shouldn't
> > > try to do so at the same time or strange things could happen. Where
> > > possible, use Samba to get to any shared devices where you want
> > > both Linux and the virtual machine to access something.
> >
> > I remember someone saying this several months ago at an NTLUG presentation
> > on VMWare, and I remember having the same reaction then.
> >
> > This limitation about accessing the CDROM etc. under VMWare & Linux at the
> > same time surprises me.  One would think that Linux simply treats VMWare as
> > another user process.  Therefore, contention for hardware devices between
> > processes would be resolved in the same fashion as when all of the
> > processes are normal Linux programs.  Granted, if VMware accesses /dev/lp*
> > directly, rather than going through lpd, you can run into problems, but
> > this shouldn't won't affect the CDROM.
> 
> Ah, but if VMWare grabs control at a low enough level that it is actually
> aware that the CD-ROM is a CD-ROM, then that means there'll be some
> contention.
> 
> If it's able to mount/dismount the CD, for instance, that requires enough
> control that this may head us into "contention land."  And when Windows
> processes think they need to know about something actually being a CD-ROM,
> as opposed to "just another filesystem that's mounted," that directs us in
> the "perhaps dangerous" direction...
>