[dm-devel] Re: namespaces (was Re: [Q] don't allow tmpfs to page out)

[Andries Brouwer]

On Thu, Jul 15, 2004 at 01:31:08PM +0100, Paul Jakma wrote:

> speaking of which, how does one use namespaces exactly? The kernel 
> appears to maintain mount information per process, but how do you set 
> this up?
> 
> neither 'man mount/namespace' nor 'appropos namespace' show up 
> anything.

Try "man 2 clone" and look for CLONE_NEWNS.

Somewhere else I wrote

  Since 2.4.19/2.5.2, the clone() system call, a generalization of
  Unix fork() and BSD vfork(), may have the CLONE_NEWNS flag, that
  says that all mount information must be copied. Afterwards, mount,
  chroot, pivotroot and similar namespace changing calls done by this
  new process do influence this process and its children, but not other
  processes. In particular, the virtual file /proc/mounts that lists the
  mounted filesystems, is now a symlink to /proc/self/mounts - different
  processes may live in entirely different file hierarchies.

Andries