[one-users] Looking at moving to OpenNebula with a few questions

[Fabian Wenk]

Hello Donny

On 27.10.2011 18:48, Donny Brooks wrote:
> Currently all machines have their network cards bonded and vlans passed
> over the trunked interface as we have approximately 20 vlans we use.
> This should be fairly simple to do with OpenNebula correct?

Yes, you need to create bridge interfaces for each VLAN you need. 
And then in OpenNebula create the networks (with 'onevnet create 
<template>'), more details are in [1].

   [1] http://www.opennebula.org/documentation:rel3.0:vgg

> I have a mix of local and network storage. Should OpenNebula be able to
> handle both local and SAN storage?

This is (currently) not really possible.

But let me discuss something else. As far as I guess you probably 
would like to have persistent VMs, right? The main idea of 
OpenNebula is to use it for on demand cloud computing, but 
persistent VMs are also possible.

To accomplish persistent VMs, the following broad steps are needed:
1. register the OS image for the VM in the image repository
    'oneimage register <image_template>'
2. create & start the VM with using the registered image in the 
<vm_templat>.
    'onevm create <vm_template>'

Please also read the threads "Storage subsystem: which one?" [2] 
and "Stopping persistent image corruption" [3] in the mailing 
list archive. They have some more details about the whole working 
of OpenNebula with persistent VMs and storage, which should help 
you with your decisions.

   [2] 
http://lists.opennebula.org/pipermail/users-opennebula.org/2011-October/thread.html#6616
   [3] 
http://lists.opennebula.org/pipermail/users-opennebula.org/2011-October/thread.html#6617

> All raid is hardware based. With the current setup what is the best way
> to set it up for best fault tolerance/speed/space?
> What is the best OS to start with? We currently use Centos 5.5 on all 3
> nodes but would prefer Fedora or similar. Debian would be doable also.

About the RAID and storage solutions the thread linked above 
should also help with your decisions. Regarding the Linux 
distribution, I guess you should use the one which fits the 
available know-how in your team.

> Would I be able to import the existing virtual machines that are running
> into OpenNebula?

Yes, you need to register a persistent image ('oneimage register 
<image_template>') with the current image as start and then 
create the VM, as described above.

> We are a small state government agency with little to no IT budget so I
> have to work with what I have. Please keep that in mind before
> suggesting "why not buy such and such...". Thanks in advance for the input.

The OpenNebula documentation describes the front end (where the 
OpenNebula deamons run) and cluster nodes (where the VMs run), 
but it is possible to combine it on a single system, see [4]. So 
for example you could then use the system xen-test as your test 
system with front end and cluster node on the same server. And 
for production use the system xen1 as front end and cluster node, 
and xen2 only as cluster node.

   [4] 
http://lists.opennebula.org/pipermail/users-opennebula.org/2011-October/006748.html

I hope this will give you some more insight into OpenNebula and 
points you to some possible ways to migrate your current setup. 
Feel free to discuss further things on the mailing list.


bye
Fabian