[Linux-ha-dev] new stonith external plugin

[Andrew Beekhof]

On 1/29/07, Serge Dubrouski <sergeyfd at gmail.com> wrote:
> On 1/29/07, Andrew Beekhof <beekhof at gmail.com> wrote:
> > On 1/29/07, Serge Dubrouski <sergeyfd at gmail.com> wrote:
> > > On 1/29/07, Andrew Beekhof <beekhof at gmail.com> wrote:
> > > > On 1/29/07, Serge Dubrouski <sergeyfd at gmail.com> wrote:
> > > > > On 1/29/07, Lars Marowsky-Bree <lmb at suse.de> wrote:
> > > > > > On 2007-01-29T10:10:44, Andrew Beekhof <beekhof at gmail.com> wrote:
> > > > > >
> > > > > > > >Attached is an update version. It supports on and off commands now.
> > > > > > > >User still have to configure hostlist in a form "node:xen0_host
> > > > > > > >node:xen0_host ...".
> > > > > > > thats going to be a pain when the VMs are also resources (and therefor
> > > > > > > moving around).
> > > > > > >
> > > > > > > or aren't we dealing with this case here?  i loose track sometimes :-)
> > > > > >
> > > > > > That's not being dealt with, AFAIK. In that case, the command wouldn't
> > > > > > be a xm shutdown/start, but a "crm_resource ..." invocation; potentially
> > > > > > one trying to stop a specific clone. I'm not sure _you_ want to deal
> > > > > > with that yet. ;-)
> > > > > >
> > > > > > However, I think it could be simplified.
> > > > > >
> > > > > > First, in many cases, all the virtual guests are going to be on a single
> > > > > > physical node. (ie, test "clusters".) Then only supplying one node to
> > > > > > ssh to should be sufficient.
> > > > >
> > > > > Let's nod discuss trivial cases.
> > > > >
> > > > > >
> > > > > > Second, by providing a simple list of all physical nodes, the system
> > > > > > should be able to automatically figure out which node it needs to ssh to
> > > > > > to shot the guest. It could try to autopopulate the hostlist from
> > > > > > /etc/xen/vm/* or some other directory, as well.
> > > > >
> > > > > Ok, Let's say user provided us with 3 Xen0 Nodes and ALL 3 of them
> > > > > have config file for node1 in /etc/xen/vm. Then where should I start
> > > > > node1 when "on" command is called?
> > > >
> > > >
> > > > wouldn't you just use the same node name that you used for "off"?
> > > >
> > > > or are "on" and "off" distinct operations sent to you from the stonithd?
> > > >
> > > > by that i mean that stonithd will never just tell you to turn a node
> > > > on, only to stop or reset it in some way.  so if you were able to do
> > > > the "off", then you know you can also do the "on".
> > > >
> > >
> > > That means that I'll have to keep a track of previous calls which I
> > > actually don't want to do. The problem is that I couldn't find any
> > > documentation on STONITH specifications and just used ssh plugin as an
> > > example. I don't know in what order commands can be sent to me and
> >
> > well thats step #1 then :-)
>
> You mean writing documentation?

nod.  unfortunately the person that wrote stonithd has left the project :(

> > because there's no point making our life harder or sacrificing
> > features if we dont have to.
>
> Absolutely agree. That's why I tried to give a user full control of everything.
>
> >
> > > what should I do if I receive "on" without previous "off". Actually
> > > "on" is the most complex thing if I didn't have to implement it I
> > > could go with a simple list of all possible Xen0s (like Lars said) and
> > > easily implement "off" and "reset".
> > > Another problem is that I don't want to do any complex tasks on
> > > "status" command. Status is called very often (every 5s or so) and
> > > putting complex logic (especially calling ssh to check Xen nodes) on
> > > that function would be too expensive.
> > > _______________________________________________________
> > > Linux-HA-Dev: Linux-HA-Dev at lists.linux-ha.org
> > > http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
> > > Home Page: http://linux-ha.org/
> > >
> > _______________________________________________________
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> >
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