[ClusterLabs] Antw: Re: design of a two-node cluster

[Lentes, Bernd]

Ulrich wrote:

> 
> >>> "Lentes, Bernd" <bernd.lentes at helmholtz-muenchen.de> schrieb
> am
> >>> 08.12.2015 um
> 09:13 in Nachricht <00a901d13190$5c6db3c0$15491b40$@helmholtz-
> muenchen.de>:
> > Digimer wrote:
> >
> >> >>> Should I install all vm's in one partition or every vm in a
> >> >>> seperate partition ? The advantage of one vm per partition is
> >> >>> that I don't need a cluster fs, right ?
> >> >>
> >> >> I would put each VM on a dedicated LV and not have an FS
> between
> >> the
> >> >> VM and the host. The question then becomes; What is the PV? I
> use
> >> >> clustered LVM to make sure all nodes are in sync, LVM-wise.
> >> >
> >> > Is this the setup you are running (without fs) ?
> >>
> >> Yes, we use DRBD to replicate the storage and use the /dev/drbdX
> >> device as the clustered LVM PV. We have one VG for the space (could
> >> add a new DRBD resource later if needed...) and then create a
> >> dedicated LV per VM.
> >> We have, as I mentioned, one small LV formatted with gfs2 where we
> >> store the VM's XML files (so that any change made to a VM is
> >> immediately available to all nodes.
> >>
> >
> > How can i migrate my current vm's ? They are stored in raw files (one
> > or two).
> > How do I transfer them to a naked lv ?
> 
> For migration the image must be available on both nodes (thus gfs2).
> 
> >

Hi Ulrich,

the migration i meant is the transition from my current setup (virtual
machines in raw files in a partition with filesystem) to the one
anticipated in the cluster (virtual machines in blank logical volumes
without fs). How can I do that ? And can I expand my disks in the vm
afterwards if necessary ?
But the "other" migration (live-migration of vm's) is of course also
interesting. Digimer wrote if I have my vm in a blank logical volume
without fs, which is placed on a SAN, I can live-migrate because the
process of live-migration takes care about the access to the lv and I
don't need a cluster fs, just cLVM.

Bernd
   

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