What Citrix is doing with Xenserver | Hacker News Reader

What Citrix is doing with Xenserver

xenserver.org

59 pointsguiambros23 comments

I recommend everyone using XenServer to move to XCP-ng [0]. They take the XenServer sources, remove licensing restrictions and add some great new features etc (like nfs4.1, ZFS etc.). They're from the same people behind Xen Orchestra (web-based console for XenServer) [1], and offer pro support like Citrix [2].

I was about to move off XenServer with the recent changes to licensing [3] (tl;dr they removed a bunch of features from the free edition), but XCP-ng has allowed me to continue with XenServer whilst make few changes to my already-working setup.

[0] https://xcp-ng.org/

[1] https://xen-orchestra.com/#!/xo-home

[2] https://xcp-ng.com/

[3] https://xenserver.org/blog/entry/xenserver-7-3-changes-to-th...

> They take the XenServer sources, remove licensing restrictions

Um, how exactly? You generally can't take software with licence X, and republish it with license Y...

I believe OP is referring to the feature restrictions that Citrix put on the free version, rather than changing the licence of the code.

I don't know about this case, but it's not that rare to see source code published under ex. Apache 2 while official binaries are proprietary or something (see ex. Caddy), in which case it's easy enough to just grab the source, enable all features, and distribute the result. Arguably similar to what AWS did with Elasticsearch recently.

Oh, good. So Citrix doesn't get to make it effectively proprietary. Like Oracle and MySQL leading to MariaDB.

Absolutely agree, I migrated us from XenServer 7.2 to XCP-ng 7.6 without issue and the community has been great.

https://smcleod.net/tech/2019/02/11/hello-xcp-ng.html

It's funny how they went from renaming completely unrelated projects to "XenSomething" (like XenApp) to removing "Xen" from "XenServer".

Hi there :) [XCP-ng project](https://xcp-ng.org) founder here. I made a presentation during last FOSDEM for those who want to learn more about this free/libre/Open Source fork from XenServer/Citrix Hypervisor: https://www.youtube.com/watch?v=VpGC5zuLjSs

25 minutes, questions included, with a recap on why and how!

Does anyone actually use Xen as a VM host anymore? I thought it was pretty much dead?

Isn’t most of the legacy AWS EC2 stuff Xen?

Big and little providers are still using it. AWS and Prgmr.com, for example.

AWS is beginning to migrate away from it towards their in-house stuff, though.

(And though you're correct with regards to the question, I don't believe AWS uses Citrix's XenServer.)

Is the Xen VM host distinct from Xen the hypervisor? I'm pretty sure QubesOS still uses Xen for that.

No, Xen and XenServer are distinct because of that. The host OS can in theory be any OS (but almost always GNU/Linux). Xen is a type 1 hypervisor running before the OS kernel is even loaded.

Everyone not using KVM is using Xen, for local installs that is. There are other products but none of them are open enough to be considered in those cases.

That's probably broadly true, but on the low-end there are a lot of shared-hosting companies who use nothing, and a bunch of people sharing resources via OpenVZ etc.

Hence the 'for local installs that is' ;-)

There are generally two big FOSS hypervisors (Xen, KVM), a bunch of smaller ones (bhyve, vmm, the one in l4) and the somewhat-open ones like VirtualBox-OSS.

Then again, the whole local setup scope is a niche in itself.

I'm curious what led you to believe Xen was dead...?

There have been notable departures from Xen to KVM in the hosting space. Linode, for example. And while I did note in another comment that AWS uses Xen, it is also migrating away to KVM. Their firecracker VM is also KVM based. It seems fair to characterize it as legacy...though perhaps not dead.

The company I work for produces a VM based product and distributes at least 100 instances (copies of the VM product) a month. We ask what VM platform (and have maintained Xen support) in more than a year not one person has bought a Xen instance. Tons and tons of Hyper-V a fair bit of Vmware and a boat load of KVM variations (Generally using Proxmox and VirtualBox, or a taste of doing it ourselves) but never Citrix. I believe of the 3000+ instances we support only about 100 are Xen based.

Bit of a surprising comment - Xen is very widely used - even all of AWS is Xen (I believe), are you perhaps thinking of XenServer (Citrix's OS / Distro based on Xen)?

If you do mean XenServer, well - yes some large places are still using it but it's definitely dying out after they proved very slow to deliver new features then put a restriction on free / open source users as of 7.3 onwards that prevents clusters great that 3 hosts rendering mostly useless.

XCP-ng (https://xcp-ng.org/) is a fork of XenServer which is picked up where XenServer left off and is doing a lot in a short period of time (IMO) to add new features and build / support the community.

> even all of AWS is Xen

Majority, but the latest generation ("nitro") uses KVM.

AWS has been maintaining there own custom version for more than 2 years based on the open source code, and mostly use KVM now from what I understand.

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