[Users] general (totally noob) questions...

[Itamar Heim]

On 09/25/2012 06:10 PM, Michael Hauber wrote:
> On Sunday, September 23, 2012 03:13:56 PM Itamar Heim wrote:
>> On 09/22/2012 08:00 AM, Michael Hauber wrote:
>>>
> <<snip>>
>>>
>>>
>>> Questions:
>>>
>>> 1.  As I understand it, a N-to-N configuration means that there will be
>>> load balancing between the nodes as well as failover.  Is the load
>>> balancing something that is manual (I have to monitor/balance the load
>>> manually, or is it done automatically?)
>>
>> ovirt has load balancing based on cpu load for either power saving or
>> even distribution.
>> more types and custom scheduling are coming.
>>
>>> 2.  If it is done automatically, how do the loads get split up?  Is the
>>> virtual machine itself the unit of load that transfers from one node to
>>> another or does it go so far as balancing services running inside those
>>> virtual machines?
>>
>> VM is the unit of load.
>>
>>> 3.  For the fail-over, is it seemless in the sense that the user's
>>> connections don't get reset or is there a short period of down-time
>>> before the service is available again?  While this isn't a big issue for
>>> me, it is something that I've been wondering about.
>>
>> live migration is seamless.
>> failover is not, since the VM/host failed. engine needs to detect it,
>> give some grace time, then start the VM on another host.
>>
>>> 4.  Fibre channel or FCOE?  (I've spent entire evenings trying to get a
>>> straight answer through google searches, but there seem to be way too many
>>> agendas).  Being that one of the virtual servers will be a media server
>>> for
>>> the televisions (new addition), my worry is lag-time (I would like to
>>> serve at least 5 televisions without lag-time).  The array will also
>>> support things like file server, space for about 2-dozen www (family
>>> pages (lots of pictures)), space for mail, space for backups
>>> (rSync,Amanda), ISO boots, etc.
>> I am obviously out of my element here for what i use for my family :)
>> why FC and not Ethernet?
>>
>
> First, thank you for helping me understand this a bit better.
>
> Why FC...  I don't know?  I don't know how to figure out what kind of load it
> will see, so I figured that I would try for the fastest option I could afford.
> But like I said, some people swear by iSCSI, others by FC, and others by FCOE.
> Being that I've never gotten a chance to experiment with any of them (so far,
> I've just used a NFS/SMB server).
>
> I don't know if it helps to explain or not, but the following two links show
> the network I would like to set up.  The first is the physical configuration.
> The second shows the virtual machines that the cluster will run.
>
> https://mikesplace.valleygate.net/temp/VIIgate_New_Physical.png
> https://mikesplace.valleygate.net/temp/VIIgate_New_Node_VMs.png
>
> Being that it's all going to be fiber and if NAS is enough, can I also assume
> that it's safe to consolidate the storage and the "cluster" switch and
> seperate them into two vlans without any kind of performance hit (don't know
> how busy the back-channel network would be).
>
> Thanks again for the help.
>
> mchauber
>
>
>
>

NFS on 10GE would be your simplest deployment (NFS is a simpler 
deployment than block based storage)
i'd go with simple if possible.

(if 1GE isn't enough, may be for home workload)