KVM and OpenVZ Virtualization in ProxMox

In my previous post I wrote about my company's research for a good enterprise virtualization environment which supports most of the Linux and Windows operating systems as guests. We ended up choosing the ProxMox VE and I spent quite a bit of time testing and configuring it. One of the first actual implementation tasks I was faced with was virtualizing our Redmine TKL appliance. Since ProxMox provides two completely separate virtualization methods - KVM and OpenVZ container virtualization, I had to decide which one to use. Due to its nature, OpenVZ works only with Linux OSes, but it's supposed to have a better performance and use less resources, so it seemed like the way to go. The VM creation procedure in ProxMox seems pretty straightforward. For KVM one just needs to upload an ISO installation image of the desired OS, configure its parameters (CPU cores, memory, drive space, etc.), open the console via web management and follow the usual routine like on a physical machine. For OpenVZ, it's even easier, one just needs to upload an OpenVZ template, configure parameters and the system is immediatelly up and running. A walk in the park as they would say...well, yes, but where can one find the OpenVZ templates?

The quest for OpenVZ templates

ProxMox itself provides quite a few of them here and there are many at the OpenVZ template download page as well. This ProxMox related article suggested checking the Parallels website too, after all they are the creators of OpenVZ and their commercial product Parallels Virtuozzo Containers is built on top of OpenVZ, with more features and better functionality. Apparently, they do offer a load of templates here, but I couldn't find any info on both OpenVZ and Parallels website whether those templates were compatible or can be used with OpenVZ. Additionally, all those templates were "so called" EZ templates, something Parallels started using since their 3.0 version. Unlike its standard full package templates in the previous versions, it's basically a metadata file with only the information about the necessary packages, which are then installed via Virtuozzo command-line utilities. The thing is that OpenVZ has similar, although much more basic utilities, but they state that they are no longer supported making me wonder whether they can be used to create OpenVZ templates from Parallels EZ templates. Anyway, although supporting all the major Linux distros and application packages (like Joomla, Wordpress, etc.) neither the ProxMox, OpenVZ or Parallels list of templates contained anything related to TKL. At this point it seemed more likely that there are no precreated templates for TKL and the idea of creating one didn't seem like an easy task according to this ProxMox forum discussion.

TKL - OpenVZ Template creation

Still hoping to find a ready-to-use template, I started browsing the TKL forums and found this post. It had instructions how to create an OpenVZ template for any appliance, but that looked complex to me, plus there were some reservations expressed about whether it would work with all the appliances. Searching furter through related posts, I finally managed to find 2 different sourceforge projects (turnkeylinuxovz and turnkeylinuxcom) with a dozen of precreated templates. Unfortunatelly none of them contained Redmine, which meant going back and trying to figure out the whole procedure from that article. It involves utilizing a TKLPatch, a set of scripts for customizing and extending any TKL appliance. The instructions here explain more about how to use it. Combining all this and putting 2 and 2 together, here are the exact steps that I did:

1. Installed TKL Core appliance as a virtual machine. I used ProxMox for this - IMPORTANT NOTE! - the first time I tried it I installed TKL Core as OpenVZ by using a template from turnkeylinuxcom and the scripts didn't work, there were errors. In my second attempt I downloaded TKL Core ISO image and virtualized it under KVM and everything run fine. I'm sure any other full virtualization method would work (the article suggested Virtual Box). I used KVM since I had it already available under ProxMox.

2. Installed TKL Patch via following commands:

3. Downloaded TKL Redmine appliance ISO image and copied it to the TKL Core virtual machine, to the folder /tkl-openvz/ that I previously created.

4. Downloaded Kit for OpenVZ from that article, unpacked it. It contains 3 files - tkliso2ovz and tklpatch-gen-ovztemplate scripts, which I copied to /usr/local/bin/ as per instructions and tklovz.tar.gz, which I placed in the same folder as TKL Redmine ISO image.

5. I went into the /tkl-openvz/ that I created and run the following command:

6. The command produced the following OpenVZ template file in the same folder:

7. I tried to upload that file to the ProxMox list of OpenVZ templates, but got an error due to ProxMox specific naming convention requirement:

I renamed my file to:

and ProxMox accepted it.

8. Finally I started the VM in ProxMox, it was instantly functional without any installation procedure which is characteristic for OpenVZ. We run the TKLBAM restore process and all our Redmine data appeared within few seconds. We tested it further and everything seemed to work okay.

Universal Solution

That's it, I guess the procedure should work for any TKL appliance. The previously mentioned forum post did say that there may be problems, they specifically mentioned the Redmine appliance, but the scripts seem to have been updated since and the last remark is from January 2011, so I hope they fixed all the errors in the meantime. In any case, we've been running our Redmine for almost a month now without any problems.