[ale] Small Clusters for VMs

[DJ-Pfulio]

Jim, Would you run oVirt at home for 2 boxes with dual-core CPUs and 8G of RAM
each?  Make redundant storage and VMs.  THAT is the problem and I think there is
a relatively simple solution with minimal config or scripting to solve it.

On 10/28/2016 12:28 PM, Jim Kinney wrote:
> On Fri, 2016-10-28 at 10:49 -0400, DJ-Pfulio wrote:
>> Thanks for responding.

>> Won't be using oVirt (really RHEL only and seems to be 50+ different
>> F/LOSS projects in 500 different languages [I exaggerate] ) or XenServer
>> (bad taste after running it 4 yrs).  I've never regretted switching from 
>> ESX/ESXi and Xen to KVM, not once.
> 
> Ovirt is only 49 projects and 127 languages! Really!

If someone wants to run VMs on 3 nodes oVirt seems like overkill.  Different use
case than a university, I suppose.

> A major issue for my use is the need to have certain VM up and running at all
> times. Ovirt provides a process to migrate a VM to an alternate host if it
> (host or VM) goes down. The only "gotcha" of that is the migration hosts must
> provide the same cpu capabilities so no mixing of AMD and Intel without 
> setting the VMs to be i686.

This similar CPU architecture requirement is a gotcha for all virtual machines
that support migration.  KVM-qemu included.  I haven't figured out which is the
my least capable CPU recently ... is a C2D less than a modern Pentium?  The
Pentium is faster. I need to check the flags.

>> Just doing research today. Need to sleep on it. Probably won't try
>> anything until Sunday night.

Plus I have to figure out who much storage to allocate for my trial with the
distributed storage - 20G seems just a little small.  I have many different
sorts of storage for the trial.  RAID10, Blue desktop disk, fast USB3 external,
and an eSATA Black disk. Really want to see which performs the worst - thinking
it will be the RAID10 stuff which is infiniband connected (got an amazing
deal!), but really slow otherwise.


> Download CentOS 7.2 Install VM host version yum install epel-release Follow 
> direction here: https://www.ovirt.org/release/4.0.4/ starting with: yum 
> install || 
> <http://resources.ovirt.org/pub/yum-repo/ovirt-release40.rpm>|http://resources.ovirt.org/pub/yum-repo/ovirt-release40.rpm|

So that install does libvirt, kvm-qemu, sshd, nfs, bridge-utils, and all the
distributed storage stuff automatically?  Nice!

> <http://resources.ovirt.org/pub/yum-repo/ovirt-release40.rpm> Be aware that 
> when docs refer to NFS mounts, the server for that can be one of the nodes 
> that has drive space. ISO space is where <duh> iso images are kept for 
> installations. I have one win10 VM running now for a DBA with specialty tool 
> needs.

Have 1 Win7 VM running to record TV and run Quicken from time to time. It can
be down, when nothing is being recorded ... so basically any time other than
prime time or football time. ;)  It will be one of the first VMs I migrate into
the sheepdog storage.  So will my daily-use desktop.

The big difference in this planned architecture is that distributed storage can
run on the VM hosts. Performance ISN'T the reason to do this.  10 users won't
notice.

That's my plan right now, anyway.  Sleep can alter it.

>From the comments, it appears is that
a) nobody has used sheepdog in their environment (it isn't new).
b) nobody is interested in cluster VMs on a small scale.
c) nobody is interested in using small scale systems as redundant Linux storage
for qemu VMs - someone did make a way to mount it outside a VM.
     or
d) everyone is busy enjoying fall and has more important things on their plates
today!  Which I can understand.

It is interesting how different people come at a problem and get different
answers. ;)