VIrtualization HA challenge

[Tom Metro]

Rich Braun wrote:
> My goal is basically to be able to walk into anyone's data center with a set
> of well-tested tools that provide compelling HA and monitoring capability
> without all the equipment/software expense of the VMware solution...

My interest is in being able to set up "mini clouds" for development and
staging, which are easy to manage, and have high guest and API
compatibility with hosted cloud service providers, so guests can easily
be migrated to the public cloud.


> I've spent the past couple months tinkering with tools for high-availability
> and virtualization; what seems tantalizingly possible is this setup:
> 
> - Two multi-core systems with two NIC cards and 4-6 SATA drives, 16-32GB of RAM.
> - Xen or VirtualBox virtualization.
> - Two ethernet switches, at least one of which is jumbo-frame capable (for use
> as a SAN switch).
> - Open-source SAN with automatic failover of all the storage contained in
> these systems.
> - Virtual machines capable of running on either of the two hosts.
> 
> There's an open-source project called Archipel (archipelproject.org) which
> I've yet to investigate.  A good writeup of the state of the art is at
> Aliver's blog:  http://aliver.wordpress.com/ , the 2-Jan entry.  Another
> article I find interesting is by Mike Neir (http://mike.neir.org/weblog/lvm).

Have you explored any of the options further since posting this in January?

It seems a lot of people are working on a "cluster-in-a-box" solution,
so chances are good we'll see something decent emerge.

Absent from the links or blog above is mention of Eucalyptus
(http://www.eucalyptus.com/), the cloud solution Ubuntu promotes (or at
did?). I was never all that enthused about Eucalyptus due to its focus
on Xen. (KVM and OpenVZ seems like far cleaner and more efficient, if
you are Linux-centric.) I haven't kept up with it, so I don't know if
that has changed.

I just ran across CloudStack
(http://cloud.com/products/cloud-computing-software) - another option in
this field. (There was a LinuxFest Northwest talk on this,
http://linuxfestnorthwest.org/sessions/build-free-freedom-cloud, which
may be available online at some point.)

It claims to provide support for Xen, KVM, HA fail-over, web UI for
management, and Amazon EC2 Compatibility layer, with a GPL3 license.
"CloudStack supports any storage solution as long as they are standard
iSCSI or NFS compliant." So it doesn't bundle a tool to address the
storage question.

Proxmox VE (http://pve.proxmox.com/wiki/Main_Page), mentioned in
Aliver's blog, looked promising. It possibly provides greater storage
management (http://pve.proxmox.com/wiki/Storage_Model), though it sounds
like a lot of setup is still left to the implementer. (Obviously there
is a tradeoff between flexibility and turn-key automation, but I'd like
to see a default install that sets up network replicated storage.)


> I say it's "tantalizing", though, after getting various pieces work
> individually but not quite integrated:  AoE (ATA-over-Ethernet), OCFS2, DRBD,
> VirtualBox.

The storage architecture is definitely a big piece of any solution, with
a lot of moving parts, and numerous decisions to be made. Two nodes with
network replicated local storage seems ideal for a small cluster, but
then what happens when you add a 3rd node?

I've also heard mixed messages on the production readiness of things
like DRBD.

 -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/