[ClusterLabs] Antw: Re: principal questions to a two-node cluster

[Andrei Borzenkov]

В Thu, 23 Apr 2015 15:53:49 +0200
"Lentes, Bernd" <bernd.lentes at helmholtz-muenchen.de> пишет:

> Michael wrote:
> > >
> > > - If I will use logical volumes, do I need cLVM ? Or is "normal" LVM
> > > sufficient ?
> >
> > If you want your LVMs either on the left or the right node, plain LVM is
> > sufficient. If you want part or your LVMs to run on the left node while
> > the other parts runs on the right node, you need cLVM. And DLM.
> 
> OK.
> I'd like to have some VM's running on node A and some _others_ on node B.
> So I will use cLVM.
> 

It does not matter how many VMs are running left and right. What
matters is, whether those VMs are using the same VG resource or not. If
you have some VGs for VMs on node A and some for VMs on node B,
there is absolutely no need for cLVM.

Of course in this case all VMs on one VG can only be relocated
together. If you want ultimate flexibility, shared filesystem will be
needed indeed.