[one-users] ONE 3.2 general questions

[deeepdish]

Hello Everyone,

We're evaluating OpenNebula 3.2 in our environment and have a few questions:

*  What is the most optimal (and recommended) approach to provide redundancy / HA for front-end processes (oned and sched).   I've been looking into drbd-type approaches, however I'm sure others already have this in their environments, and I'm hoping someone can provide guidance on the most reliable / best approach to achieve this.

* Is it possible to (easily) build an image using ONE?  At the moment we use another VM manager to build a KVM image, convert the qcow2 file to raw and import into ONE.   It would be easier to build the image using ONE.   Although it seems possible, it seems like a disconnected process in making multiple templates, saving disk images, and managing (temporary) ISO media.   

* Is it possible to change a deployed VM (template)?   To clarify specifically:  assume a deployed VM, and the requirement to add another disk / or contextualization variable to an already deployed VM.    I've noticed that by simply updating the template from which the VM was deployed from, does not change the already deployed VM.   I would like to avoid deleting and re-provisioning VMs for minor template changes.

* Is it possible to separate images/templates from VM data files?   Currently everything located in the /var/lib/oneadmin home directory.   Ideally we'd like to split the data associated with templates/images/ISOs, etc and the actual VMs we deploy.

* Is it possible to have MULTIPLE VM_DIRs defined?   We are considering the use of CLVM (see question below) or OCFS2 to provide shared volume / file system access.   The question relates to data classification and scaling data store capacity.   Expansion of an OCFS2 FS is not possible, and migration to a larger volume involves downtime.   Deploying additional VM data stores will provide the scalability we're after.   CLVM would also allow us to add additional physical devices to a logical volume.

* I noticed that ONE comes with TM_LVM.   Does this imply that CLVM is supported?   Relating to the above question, can we have multiple volume groups defined for data classification purposes?   Are there any other considerations / dependancies that are necessary to enable CLVM support under ONE?

* How does ONE scale to support multiple zones?   My understanding (based on documentation) is that ONE follows a manager of managers model when it comes to zones.   A ONE front-end (master) instance can administer downlevel (slave) ONE front-end instances that themselves manage hypervisors.   Assuming HA is possible, this leads me to believe that two (2) ONE Front-End servers are necessary for every zone, in addition to two (2) ONE front-end servers for the manager of managers function (master).   Given this approach, sclability can dramatically increase cloud overhead (physical to virtual server ratio), especially for multiple datacenters (data center = 1 zone) hosting 3-6 compute nodes each (this equates to 5-8 physical hosts considering HA front-end servers).     UNLESS....   There are ways / methods that are proven and would be supported under a C12G maintenance contract that we can virtualize these ONE front-end servers...


Thank you.