Hello,

I work for Ark Data Center where we use a whole lot of VMware's Fault Tolerant Solution, but as a personal project I would like to piece together an open source fault tolerant solution that mimics VMware's to the fullest.

So I guess my question is this: Is this forum a good place to call home when it comes to these sorts of IT issues?

Thanks for listening,

PS: Here's my punchlist

*Configuring Linux to be a JEOS (Just Enough OS) to be considered as close to "bare metal" as possible.
*Install/Configure Xen for virtualization/fault tolerance. (actually it is HA, but w/e)
*Prove that the fail-over works as intended on both the virtual servers and the host.

Ahem, do you know the difference between HA and FT?

Yes I am using the term FT when it's actually HA. Sorry about that.

OK, so you want HA. Linux or rather OSS, has quite a few HA systems, like keepalived or pacemaker.

If you want VM specific HA, you might want to start looking at systems that have it bundled, much like vsphere - oVirt, RHEV etc

Isn't Dom0 the equivalent to vSphere? I have been under the impression that Xen has an addon for VM HA, is this correct?

No idea about Xen, I don't use it. KVM is the Linux native hypervisor, Xen isn't part of Linux

Anyone here familiar with Xen? I think it is a better solution for me than KVM.

Why do you think so?

I think so because I don't need just virtualization, I need automatic fail-overs and automatic vm repair/orphan cleanup.
I am trying to mimic vsphere to the fullest, and I just haven't read anywhere that KVM can do this.
If it is possible with KVM, please let me know.

Edit: what I need is something like xenmotion.

KVM and Xen both cannot do this, they are only hypervisors. Vsphere isn't a hypervisor, it's a complete virtualization management system, which controls ESXi hosts, which in turn run a kernel (vmkernel+linux parts), a hypervisor and other parts. vsphere hides the complexity from you, Xen and KVM do not.

So basically, what you're looking for can be achieved with KVM, but you need to look at full stacks, not just the hypervisor. That would be the aforementioned oVirt(open/free/upstream) or RHEV (supported-tested-maintained/downstream), or maybe Proxmox (which I consider rather weird, due to the mix of userspace/kernel from different distributions).

Now, if you look at oVirt (my quite obviously biased favourite), you have automatic failovers out of the box. Not sure what you mean by orphan healing and cleanup, never had any orphans in oVirt either way, this might be some silly vsphere bug treated by a "feature". You also get a bunch of other features vsphere has, and some it doesn't, especially if you're looking to scale (how do hundreds of hosts per single cluster sound? Or cloud component integration? Or out of the box VDI and server capabilities, no additional software or licenses required?). Live migration, both for VMs and storage are also there out of the box, as well as performance and scaling perks that vmware can only dream of. Again, Xen probably has something similar built on top of the hypervisor, I suspect that would be xenserver or somesuch, but I am not very well aware of the featureset there.

In short, if you want vsphere functionality and not just a host to bring up a vm or two on, you need to start comparing apples to apples, and full fledged virt systems to such systems, and not to standalone hypervisors, which are just a single component in such systems.

1 members found this post helpful.

Thank you Dynasty, I can't wait to get home and chew what you just said.

So I finally digested the above statements and have decided that I will start barking up the oVirt/KVM tree. I've noticed that oVirt only officially supports a few distributions, so is it best to go with something like a CentOS minimal install? (I'm trying to go baremetal here)

I looked into TurnKey Linux and they don't seem to have what I need, so then I thought well maybe DSL-N is small enough for my purposes, but then I read that oVirt is mainly for CentOS. I would like to get started as soon as possible, I am just unsure of the first step here. (Which OS to pick)

Also, let me make sure I am understanding this correctly:
Step 1: install a (hopefully) minimal OS.
Step 2: install KVM
Step 3: install oVirt
step 4: start spinning up VM's and configuring via oVirt.

Edit: I would really like to use Ubuntu if possible since I'm most familiar with it.

Use the CentOS "Virtual Host" installation. If you install Minimal, you will end up just installing the missing packages anyway.

1 members found this post helpful.

A Centos minimal install is all you need for oVirt, it will add the rest of the required packages on its own. BTW, there is no such thing as baremetal in x86 virtualization, only loads of marketing bs companies like vmware load on you. Even hypervisor types aren't relevant nowadays, because KVM pretty much broke the difference between type 1 and type 2.

The steps are rather different
1. install the first centos host (minimal)
2. install the engine (controller node, thing vcenter)
3. install hosts (centos minimal)
4. add nodes to engine (will automatically add missing packages and start using the host).

How much hardware do you have? What do you want to use for storage?

questions:

Why are there 2 hosts? Is that not an insane waste of resources?

why am I having yum problems with CentOS Minimal? It's as if there is no internet at all. (It's installed on a virtualbox VM.)

Sorry, I'm not familiar with rpm based distros AT ALL.

Answers:

I have enough hardware to test with

and I would like to use internal hard drives for storage if possible. If not, I can build a SAN or something.