# OpenVZ versus Xen or others **URL:** \ **Category:** Deployment\ **Created:** [February 8, 2007, 6:22pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924 "2007-02-08T18:22:46Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 8, 2007, 6:22pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/1 "2007-02-08T18:22:46Z")
Hi again. All the great assistance so far has moved me along. I’m still a Linux noob but I’ve settled on CentOS 4.4 and have it up and running on a test server right now. I’ll be testing two scenarios: one with Apache 2.2 and mod\_proxy\_balancer in front of a mongrel cluster, and another with NGINX in front of a mongrel cluster. Remeber I have 3 machines with dual, dual-core Xeons and 16gb of ram per server and I want to maximize the performance, 146gb of storage on two and a 73gb mirror with a 600gb raid 5 on the last one (I had intended to use the raid5 for the mySQL database). So I’ve looked into virtualization a bit to see what the benefits might be and it sounds great. Now I noticed that XenExpress only supports up to 4gb of ram and I understand there may be a mySQL 4gb per process limit as well. I could buy commercial Xen but I found OpenVZ (open source branch of Virtuozzo) and it sounds pretty good too. I understand that each solution accomplishes virtualization in different ways though so any guidance would be appreciated. Also, my initial quess is that I should be able to put about 2 or 3 virtual servers on each machine, including the database server and have the two webservers being fed by a hardware load balancer and accessing the 3rd server for mySQL data. Again, thanks for any guidance! Raul ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 9, 2007, 4:31am UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/2 "2007-02-09T04:31:46Z")
Raul wrote: > virtualization a bit to see what the benefits might be and it sounds > great. Now I noticed that XenExpress only supports up to 4gb of ram and > I understand there may be a mySQL 4gb per process limit as well. I > could buy commercial Xen but I found OpenVZ (open source branch of > Virtuozzo) and it sounds pretty good too. I understand that each > solution accomplishes virtualization in different ways though so any > guidance would be appreciated. We’ve been testing both of these solutions out. Xen is pretty rocking if you want to manage several different distros and such. Each virtual server has it’s own kernel running with Xen… which will take more resources on the server than OpenVZ. There is also the overhead of managing that many more servers/kernels. OpenVZ shares it’s kernel with each of the virtual machines and works more like a FreeBSD jail. One of the cool features that really caught our attention as we’ve been investigating tools for our new product is live migrations! “Delivery of the checkpointing and live migration functionality as part of OpenVZ brings a capability that no other open source operating system-level virtualization software offers. It allows system administrators to move virtual servers between physical servers without end-user disruption or the need for costly storage capacity.” [http://openvz.org/news/announcements/kernel-2.6.9-stable-20061114](http://openvz.org/news/announcements/kernel-2.6.9-stable-20061114) …pretty cool, huh? -Robby – Robby R. [http://www.robbyonrails.com/](http://www.robbyonrails.com/) > **[Planet Argon](https://www.planetargon.com/)** > > Planet Argon is a Ruby on Rails development agency specializing in maintenance and support for existing Rails apps. Based in Portland, OR, Planet Argon has been a member of the Rails community since 2004. ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 9, 2007, 5:47am UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/3 "2007-02-09T05:47:51Z")
On Feb 8, 2007, at 7:30 PM, Robby R. wrote: > > ram per > > Virtuozzo) and it sounds pretty good too. I understand that each > > OpenVZ shares it’s kernel with each of the virtual machines and works > > end-user disruption or the need for costly storage capacity." > > [http://openvz.org/news/announcements/kernel-2.6.9-stable-20061114](http://openvz.org/news/announcements/kernel-2.6.9-stable-20061114) Ummm… Xen can do this too. > …pretty cool, huh? definitely cool, to be able to move a whole VM from one host to another without any down time is kick ass 😉 > -Robby > > – > Robby R. > [http://www.robbyonrails.com/](http://www.robbyonrails.com/) > [http://www.planetargon.com/](http://www.planetargon.com/) Xen outperforms openvz. It also doesn’t allow the host to oversell boxes. OpenVZ allows physical resource to be oversold based on the premis that hopefully not all of the VM’s go nuts with cpu and mem at the same time. If this is your own 3 servers and you have lots of ram then I think Xen is the better choice. You do pay for running a kernel for each VM but you gain better isolation and performance for this. Cheers- – Ezra Z. – Lead Rails Evangelist – removed\_email\_address@domain.invalid – Engine Y., Serious Rails Hosting – (866) 518-YARD (9273) ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 9, 2007, 1:02pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/4 "2007-02-09T13:02:27Z")
I’ve had experience with both OpenVZ and Xen on with different hosting companies. The OpenVZ server we had with [vpslink.com](http://vpslink.com) just would not install Oracle XE. It was a problem with swap memory. The VPS at vsplink didn’t have any, and even though it had plenty of memory Oracle would just crap out during install. I’m not sure if this is related to some limitation with OpenVZ, but most Xen hosts I’ve seen give you some swap, too. I even tried enabling my own swap, but it just wouldn’t work. My problems may have had more to do with the suckiness of Oracle than anything else. Their install script for XE just directs error messages to /dev/null, so I spent many hours trying to figure out why the Oracle install “completed successfully” but was broken when I tried to use it. You’ve been warned. Paul ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 9, 2007, 6:27pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/5 "2007-02-09T18:27:06Z")
OK thanks everyone! I actually got CentOS 4.4 running flawless on one of my servers and everything looked great. Then I followed the OpenVZ install instructions and it worked fine. I have 3 VPS’s running on this machine. And then, suddenly remembering what a linux noob I am, I wondered “What now?”. 🙂 I could see that I have 3 vps each with their own IPs etc but couldn’t figure out how I was then going to install my apps on each one etc. I guess I really gotta get my head around linux before anything else. It sounds like I’ll be trying XenExpress to see how it works and determine if I’ll need to be buying Xen commercial to go forward (if I use Xen I need the multiprocessor and 16gb ram support). When you get right down to it I really just want Apache or Nginx running with as many mongrels behind it as reasonable. I did set up a successful development server on Windows with Apache 2.2 and 5 mongrel services that seems to run fine, but I understand that for large scale performance of Rails and MySQL (and the ability ot automate deployment with Capistrano) that I’d be better off to go linux. Not to mention that I’ll need about $7000 in Microsoft licenses to go the Windows route!! Thanks again, I’ll keep pushing on and report back as I figure things out. Appreciated! Raul ----- Original Message ----- From: “Paul Stadig” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) To: “Deploying Rails” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Sent: Friday, February 09, 2007 4:01 AM Subject: [Rails-deploy] Re: OpenVZ versus Xen or others ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 9, 2007, 5:52am UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/6 "2007-02-09T05:52:52Z")
Ezra Z. wrote: > > > I understand there may be a mySQL 4gb per process limit as well. I > > > > without > > end-user disruption or the need for costly storage capacity." > > > > [http://openvz.org/news/announcements/kernel-2.6.9-stable-20061114](http://openvz.org/news/announcements/kernel-2.6.9-stable-20061114) > > Ummm… Xen can do this too. “the more you know…” ™ I’ll look into that more. > > …pretty cool, huh? > > definitely cool, to be able to move a whole VM from one host to > another without any down time is kick ass 😉 Yeah, I’m also curious if OpenVZ will get accepted into the Linux kernel as mentioned here: - [OpenVZ Pushing for Linux Kernel Inclusion - Slashdot](http://linux.slashdot.org/article.pl?sid=06/01/17/2251233) - and… [http://rubyurl.com/2na](http://rubyurl.com/2na) Since they both approach things _slighty_ different, it’s a good idea to consider the benefits of both before making a decision. I really _want_ to go the openvz route with a project we’re working on, but xen keeps coming back to surprise me. Robby – Robby R. [http://www.robbyonrails.com/](http://www.robbyonrails.com/) > **[Planet Argon](https://www.planetargon.com/)** > > Planet Argon is a Ruby on Rails development agency specializing in maintenance and support for existing Rails apps. Based in Portland, OR, Planet Argon has been a member of the Rails community since 2004. ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 9, 2007, 9:53pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/7 "2007-02-09T21:53:32Z")
Ezra! Thanks for the follow up! I was just looking at the > **[Citrix Hypervisor - Server Virtualization and Management Software - Citrix](https://www.citrix.com/products/citrix-hypervisor/)** > > Citrix Hypervisor provides a highly reliable and secure open source virtualization platform for cloud, server and desktop virtualization infrastructures. site and found a somewhat buried Xen 3.0 that is open source and doesn’t have the limitations of the three options on the home page. Is this the version I should be looking at? Raul ----- Original Message ----- From: “Ezra Z.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) To: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Sent: Friday, February 09, 2007 12:44 PM Subject: [Rails-deploy] Re: OpenVZ versus Xen or others ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 9, 2007, 10:00pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/8 "2007-02-09T22:00:35Z")
Yeah Xen 3.x is what you want. -Ezra On Feb 9, 2007, at 12:52 PM, Raul wrote: > > > I could see that I have 3 vps each with their own IPs etc but > > > to it I > > > Not to mention that I’ll need about $7000 in Microsoft licenses to > > > > > > > companies. The OpenVZ server we had with [vpslink.com](http://vpslink.com) just would not > > > > anything else. Their install script for XE just directs error > > > > On Feb 8, 11:52 pm, Robby R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > > > > > > > > > > > > running on a test server right now. I’ll be testing two > > > > > > > > two > > > > > > > > could buy commercial Xen but I found OpenVZ (open source > > > > > > > > server has it’s own kernel running with Xen… which will take > > > > > > > > product is > > > > > > > > end-user disruption or the need for costly storage capacity." > > > > > > > > > > \*[OpenVZ Pushing for Linux Kernel Inclusion - Slashdot](http://linux.slashdot.org/article.pl?sid=06/01/17/2251233) > > > > > Robby > > > – Ezra Z. – Lead Rails Evangelist – removed\_email\_address@domain.invalid – Engine Y., Serious Rails Hosting – (866) 518-YARD (9273) ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 9, 2007, 9:45pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/9 "2007-02-09T21:45:31Z")
Raul- I’m not sure what makes you think you need the commercial Xen for anything you mention. We run the open source Xen on boxes with 16Gig+ Ram and 4 processor cores. There is no limitation to the open source Xen afaik it can easily address 64Gigs of ram and many processors. -Ezra On Feb 9, 2007, at 9:26 AM, Raul wrote: > to it I > Not to mention that I’ll need about $7000 in Microsoft licenses to > > > companies. The OpenVZ server we had with [vpslink.com](http://vpslink.com) just would not > > the Oracle install “completed successfully” but was broken when I > > > > > > > > cluster, > > > > > > virtualization a bit to see what the benefits might be and it > > > > > > guidance would be appreciated. > > > > > > works > > > > > > administrators to move virtual servers between physical servers > > > > > > Robby > > > > > > – > > > Robby R.[http://www.robbyonrails.com/](http://www.robbyonrails.com/)[http://www.planetargon.com/](http://www.planetargon.com/) > > > > > > > > – Ezra Z. – Lead Rails Evangelist – removed\_email\_address@domain.invalid – Engine Y., Serious Rails Hosting – (866) 518-YARD (9273) ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 11, 2007, 1:54pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/10 "2007-02-11T13:54:13Z")
I too have been playing around with the different virtualization possiblities, and I believe it all comes down to one choice. OpenVZ is easier to get going but doesn’t guarantee that the hoster is not overselling. Xen is harder to get going (in my experience, due to pae quirks and other stumbling blocks) but once you get it going it’s just as easy to use and gives the customer the added satisfaction that he’ll be using dedicated hardware resources that the host machine actually has, rather than overlapping limits like you can with OpenVZ. I will be launching a vps hosting service in the next month or so but I have a lot more testing to do before I’m satisfied with my final choice. The hosting service will be aimed at rails development, not production. More details to be announced very soon. ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [February 9, 2007, 10:17pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/11 "2007-02-09T22:17:43Z")
Thanks for the guidance Ezra! Raul ----- Original Message ----- From: “Ezra Z.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) To: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Sent: Friday, February 09, 2007 12:59 PM Subject: [Rails-deploy] Re: OpenVZ versus Xen or others ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [May 27, 2008, 8:07pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/12 "2008-05-27T20:07:51Z")
Did anyone read the HP Labs report? Any performance issues with Xen? ---
**Author:** ![raul](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@raul](https://www.ruby-forum.com/u/raul)\ **Post date:** [May 28, 2008, 5:20pm UTC](https://www.ruby-forum.com/t/openvz-versus-xen-or-others/84924/13 "2008-05-28T17:20:41Z")
Hello Fernando. We use Xen at Engine Y., and have thousands of instances. We don’t experience any abnormal performance issues that we associate with Xen. – – Tom M., CTO – Engine Y. On May 27, 11:07 am, Fernando P. \