We have been running the free version of Citrix XenServer for about 2 years now and it has worked OK for the most part, but we have also had our issues with it. (problems with bootloaders on various guest OS, bugs with VDIs) and most of all, we have reached a point where our hardware is no longer supported. We cannot receive anymore updates because our DL360s are not supported for XenServer 6.5 and we are now in a position where newer operating systems are no longer being added to the templates list.

In contrast, we also have one standalone proxmox box, it has a few VMs on it, all of which are running on Linux. The OpenVZ containers, are, to say the least, amazingly efficient and I am loving using them but proxmox really lacks the ability to do any sort of HA without physical "fencing devices". That concept sounds really strange to me, and not very reliable.

In short I would like an open-source hypervisor that is:

  • Able to do HA
  • Able to do efficient Linux Container Virtualization, like OpenVZ
  • Preferably also able to do Windows
  • Supports a wide range of guest OSes (read: less restrictive than the XenServer template list)

Has anyone had any experience with something like this? I have been looking into SmartOS and OmniOS, but their ability to cluster, and many other aspects of the OS are unclear to me.

  • To do HA properly, you need something to do STONITH. This is what fencing is for. Otherwise you could have each node running and thinking the other has failed, a split brain. This is very, very bad. Oct 14, 2015 at 15:58
  • Free and HA ? That does not mix, even XenServer need a license to do HA. If you got Windows license, Hyper-V is your best bet.
    – yagmoth555
    Oct 14, 2015 at 16:04
  • @yagmoth555 Why not? You can certainly do HA with OpenStack, which is free. Oct 14, 2015 at 16:05
  • HA is by design inseparable from STONITH devices. Otherwise, it's not HA, but a recipe for a splitbrain. Having said that, you can get HA in proxmox, oVirt (my personal recommendation), and pretty much any other modern virtualization management system. If you have brandname machines, chances are you have a fencing device built in, even if it's not a full IPKVM. IPMI is good enough to reset a host.
    – dyasny
    Oct 14, 2015 at 16:09
  • @MichaelHampton Free maybe, but you will endup buying something. How you do the shared storage ?
    – yagmoth555
    Oct 14, 2015 at 16:14

1 Answer 1


Have a look at the latest release of proxmox. The HA implementation is really straight forward and works really well. The HA Simulator lets you simulate a real-world HA cluster so you can see how it works and experiment, without affecting live nodes.

See Proxmox HA Guide

It is open source, and is free to download and use. They do require a subscription to get the Enterprise updates, but the non-subscription updates work well. The latest version does not support OpenVZ. They have moved to LXC (Linux containers).

  • From what I am reading here, there is no required fencing device for this version of ProxMox?
    – Riley
    Oct 14, 2015 at 16:59
  • It uses the watchdog fencing (softdog). The hardware watchdog timer is outside of the operating system, so even with a kernel hang or crash, the watchdog would still fire.
    – Gmck
    Oct 14, 2015 at 17:15
  • That sounds promising, but has anyone had experience with the LXC containers? It doesn't look like there is much out there in the way of templates.
    – Riley
    Oct 14, 2015 at 17:34
  • 1
    Actually Turnkey Linux has supported LXC templates for quite a long time. See turnkeylinux.org/blog/announcing-turnkey-lxc - You can also make your own templates in Proxmox. Very easy and very powerful feature. There is a really good book on proxmox at packtpub.com/virtualization-and-cloud/mastering-proxmox - I highly recommend it.
    – Gmck
    Oct 14, 2015 at 18:22
  • That's cool, wasn't aware that turnkey supported them.
    – Riley
    Oct 14, 2015 at 21:05

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