[Pkg-xen-devel] Bug#655301: Bug#655301: xcp-xapi fails to start

[Ian Campbell]

On Wed, 2012-02-01 at 08:29 +0000, Mike McClurg wrote:
> On Tue, Jan 31, 2012 at 9:39 PM, Thomas Goirand <thomas at goirand.fr> wrote:
> > On 01/31/2012 03:11 PM, Ian Campbell wrote:
> >> On Sun, 2012-01-29 at 06:22 +0800, Thomas Goirand wrote:
> >>> + Note that if you wish to use Xen with XCP (Xen Cloud Platform), then using
> >>> + xl is mandatory.
> >>
> >> As I've said before I don't think this is correct. The correct value if
> >> you are using XCP is "xapi" or "xe" or however you decide to word it.
> >>
> >> Ian.
> >
> > When you choose "xm", then "xl" doesn't work. When you choose "xl", then
> > "xm" doesn't work.
> >
> > Now, whatever the value of TOOLSTACK, we have "xe" that always work. So
> > there's no consistency, maybe we should make xe to fail if TOOLSTACK is
> > set to something else than xe?
> >
> > I don't mind implementing a wrapper for xe though, which would do the
> > same thing as the wrappers we have for both xl and xe, and then package
> > the "real" xe binary in somewhere else. But then I see an issue. It
> > might well be possible to use xe only to remote-control an XCP server,
> > in which case Xen might not even be installed on the local computer. In
> > such case, xe shouldn't be set to fail, because of a wrong value of
> > TOOLSTACK.
> >
> > What's your take on this? What should I do then? Thoughts?
> >
> 
> 
> I prefer for xapi to only start when TOOLSTACK=xapi. xe isn't the
> toolstack, it's just a CLI to xapi, and the TOOLSTACK switch should
> have nothing to do with whether the user can run xe on that host. This
> is analogous to how xend would work: setting toolstack to xl doesn't
> prevent you from running xm, it just prevents xend from running, which
> makes running xm fairly useless. xe is useful even if xapi isn't
> running because it can talk to other hosts.

In theory I think xm can be used against a remote xend as well. However
I don't know how widespread that usage model actually is (nor even if it
actually works or is just a rumour). I suggest we leave that to one side
for now, given that xend is going to be deprecated in the 4.2 release.

> In my development branch of xapi, I have set the init script to only
> start xapi if TOOLSTACK=xapi. I think that this is the way that it
> should work. (But honestly, I don't care whether it's TOOLSTACK=xapi
> or TOOSTACK=xe, as long as xapi won't start unless the correct value
> is set.)

Agree wrt TOOLSTACK=xapi, but I also don't really care so long as it
does the right thing for whichever value.

It occurs to me that you might want to arrange
for /etc/init.d/xendomains to not do anything unless toolstack == xl or
xm too. Presumably xapi has it's own method for starting domains at
start of day but I'm pretty sure it isn't to call xe with xl/xm style
parameters.

Ian.
-- 
Ian Campbell


	"Do you think there's a God?"
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