[Info-vax] Orphaned processes on OpenVMS

[glen herrmannsfeldt]

Johnny Billquist <bqt at softjar.se> wrote:
(snip)

> Also, in VMS, mounting is a somewhat different process and concept than 
> in Unix. You mount a device in order to do any I/O to it. It also means 
> that just because one user have a disk mounted, that don't mean that 
> another user can do I/O on it. It can be private to only you.
> Which brings up another important point, where Unix perhaps isn't that 
> good. Bringing your own disk to a machine and mounting it. Under VMS, 
> any user can do this. There are no security issues or other problems 
> with that. Mounting is not a privileged operation.
> In Unix, this is a big no-no.

Linux, at least, now has the user option, which allows ordinary
users to mount that device.  (It is an fstab option.)  There is
also users which, in addition to what user does, allows a different
user to umount the device.  These are mostly used in the case of
floppy, cdrom, or USB drives.

In those cases, it is also usual to use the nodev option, which
tells the system not to recognize special files (like usually
go in /dev) on the disk.  That is important for security reasons.

For the private case, there is the owner option, such that only
the owner of the special file (/dev entry) can mount/umount it.

I don't know which other unix systems have these, though.

-- glen