Re: (pspace,pid) vs true pid virtualization

[Herbert Poetzl <herbert@13thfloor.at>]

On Fri, Feb 17, 2006 at 03:57:26AM -0700, Eric W. Biederman wrote:
> Dave Hansen <haveblue@us.ibm.com> writes:
> 
> > On Thu, 2006-02-16 at 12:44 -0600, Serge E. Hallyn wrote:
> >> Now Dave and I were just talking about actually using the
> >> init process in a pspace to do administration from outside.
> >> For instance, the userspace code, in /sbin/pspaceinit, which
> >> runs as (pspace 2, pid 1), could open a pipe with it's parent
> >> (pspace1, pid 234).  pid 234 can then ask the init process to
> >> do things like list processes, kill a process, and maybe even
> >> recursively talk to the init process in pspace 3.
> >
> > This would require a much smarter init, and that a child be nice,
> > cooperate and pass on what is requested of it if it's nested children
> > are to be killed.  If a child decided to be mean and ignore its parent's
> > requests, the parent can always just kill the child.
> 
> As for that.  When I mad that suggestion to Herbert Poetzl 
> his only concern was that a smart init might be too heavy weight 
> for lightweight vserver.  Generally I like the idea.

well, may I remind that this solution would require _two_
init processes for each guest, which could easily make up
300-400 unnecessary processes in a lightweight server
setup?

> > (Read the last sentence, and in case you're wondering, no I don't have
> > any children in real life)
> 
> Speaking of that.  One of my coworkers mentioned that it is unfortunate
> that our names don't have the double meaning.  So it was suggested we
> call them 
> 
> Speaking of that problematic naming.  One of my coworkers mentioned that
> it is unfortunate that our set of names does not have a double meaning.
> After that the suggestion came up to call them families, instead of guest
> or pidspaces.  Although I guess calling them guests is about as bad :)

well, at least Guests or VEs are terms already used by
existing projects, where pspace sounds somewhat strange.

at the same time I'd like to point out that *spaces is
a good name for the building blocks, but we definitely
have to name the 'construct' different, i.e. a 'guest'
(or VPS or VE or whatever) is _more_ than just a p-space
it's the sum of all *-spaces required to make it look
like a real linux system.

best,
Herbert

> Eric