We are pleased to announce the official release of Virtuozzo 7.0 Technical Preview - Containers.
It has been more than a decade since we released Virtuozzo containers. Back then Linux kernel lacked isolation technologies and we had to implement those as a custom kernel patch. Since then we have worked closely with the community to bring these technologies to upstream. Today they are a part of most modern Linux kernels and this release is the first that will benefit significantly from our joint efforts and the strong upstream foundation.
This is an early technology preview of Virtuozzo 7. We have made some good progress, but this is just the beginning. Much more still needs to be done. At this point we replaced the containers engine and made our tools work with the new kernel technologies. We consider this beta a major milestone on the road to the official Virtuozzo 7 release and want to share the progress with our customers.
This Virtuozzo 7.0 Technical Preview offers the following significant improvements:
Containers are using kernel features cgroups and namespaces that limit, account for, and isolate resource usage as isolated namespaces of a collection of processes. The beancounters interface remains in place for backward compatibility. At the same time it acts as a proxy for actual cgroups and namespaces implementation.
UUID instead of VEID for container identification. You can now identify containers by their UUIDs or names. By default vzctl will treat the former VEID parameter as name.
VCMM 4th generation of memory manager. We switched to memcg. By balancing and configuring memcg limits we will get the exact overcommit, shadow gangs, swap, page cache overuse Virtuozzo parameters. This will be done by a userspace daemon.
Odin and the OpenVZ Project announced the beta release of a new version of Virtuozzo today. This is also the next version of OpenVZ as the two are merging closer together.
There will eventually be two distinct versions... a free version and a commercial version. So far as I can tell they currently call it Virtuozzo 7 but in a comparison wiki page they use the column names Virtuozzo 7 OpenVZ (V7O) and Virtuozzo 7 Commercial (V7C). The original OpenVZ, which is still considered the stable OpenVZ release at this time based on the EL6-based OpenVZ kernel, appears to be called OpenVZ Legacy.
Odin had previously released the source code to a number of the Virtuozzo tools and followed that up with the release of spec-like source files used by Virtuozzo's vztt OS Template build system. The plan is to migrate away from the OpenVZ specific tools (like vzctl, vzlist, vzquota, and vzmigrate) to the Virtuozzo specific tools although there will probably be some overlap for a while.
The release includes source code, binary packages and a bare-metal distro installer DVD iso.
Bare Metal Installer
I got a chance to check out the bare-metal installer today inside of a KVM virtual machine. I must admit that I'm not very familiar with previous Virtuozzo releases but I am a semi-expert when it comes to OpenVZ. Getting used to the new system is taking some effort but will all be for the better.
I didn't make any screenshots yet of the installer... I may do that later... but it is very similar to that of RHEL7 (and clones) because it is built by and based on CloudLinux... which is based on EL7.
CloudLinux Confusion
What is CloudLinux? CloudLinux is a company that makes a commercial multi-tenant hosting product... that appears to provide container (or container-like) isolation as well as Apache and PHP enhancements specifically for multi-tenant hosting needs. CloudLinux also offers KernelCare-based reboot-less kernel updates. CloudLinux's is definitely independent from Odin and the CloudLinux products are in no way related to Virtuozzo. Odin and CloudLinux are partners however.
Why is the distro based on CloudLinux and does one need a CloudLinux subscription to use it? Well it turns out that Odin really didn't want to put forth all of the effort and time required to produce a completely new EL7-clone. CloudLinux is already an expert at that... so Odin partnered with CloudLinux to produce a EL7-based distro for Virtuozzo 7. While CloudLinux built it and (I think) there are a few underlying CloudLinux packages, everything included is FOSS (Free and Open Source Software). It DOES NOT and WILL NOT require a CloudLinux subscription to use... because it is not related to CloudLinux's product line nor does it contain any of the CloudLinux product features.
The confusion was increased when I did a yum update post-install and if failed with a yum repo error asking me to register with CloudLinux. Turns out that is a bug in this initial release and registration is NOT needed. There is a manual fix of editing a repo file in /etc/yum.repos.ed/) and replacing the incorrect base and updates URLs with a working ones. This and and other bugs that are sure to crop up will be addressed in future iso builds which are currently slated for weekly release... as well as daily package builds and updates available via yum.
More Questions, Some Answers
So this is the first effort to merge Virtuozzo and OpenVZ together... and again... me being very Virtuozzo ignorant... there is a lot to learn. How does the new system differ from OpenVZ? What are the new features coming from Virtuozzo? I don't know if I can answer every conceivable question but I was able to publicly chat with Odin's sergeyb in the #openvz IRC channel on the Freenode IRC network. I also emailed the CloudLinux folks and got a reply back. Here's what I've been able to figure out so far.
Why CloudLinux? - I mentioned that already above, but Odin didn't want to engineer their own EL7 clone so they got CloudLinux to do it for them and it was built specifically for Virtuozzo and not related to any of the CloudLinux products... and you do not need a subscription from Odin nor CloudLinux to use it.
What virtualization does it support? - Previous Virtuozzo products supported not only containers but a proprietary virtual machine hypervisor made by Odin/Parallels. In Virtuozzo 7 (both OpenVZ and Commercial so far as I can tell) the proprietary hypervisor has been replaced with the Linux kernel built-in one... KVM. See: https://openvz.org/QEMU
How about libvirt support? - Anyone familiar with EL7's default libvirtd setup for KVM will be happy to know that it is maintained. libvirtd is running by default and the network interfaces you'd expect to be there, are. virsh and virt-manager should work as expected for KVM.
Odin has been doing some libvirt development and supposedly both virsh and virt-manager should work with VZ7 containers. They are working with upstream. libvirt has supposedly supported OpenVZ for some time but there weren't any client applications that supported OpenVZ. That is changing. See: https://openvz.org/LibVirt
Command line tools? - OpenVZ's vzctl is there as is Virtuozzo's prlctl.
How about GUIs or web-based management tools? - That seems to be unclear at this time. I believe V7C will offer web-based management but I'm not sure about V7O. As mentioned in the previous question, virt-manager... which is a GUI management tool... should be usable for both containers and KVM VMs. virsh / virt-manager VZ7 container support remains to be seen but it is definitely on the roadmap.
Any other new features? - Supposedly VZ7 has a fourth-generation resource management system that I don't know much about yet. Other than the most obvious stuff (EL7-based kernel, KVM, libvirt support, Virtuozzo tools, etc), I haven't had time to absorb much yet so unfortunately I can't speak to many of the new features. I'm sure there are tons.
About OS Templates
I created a CentOS 6 container on the new system... and rather than downloading a pre-created OS Template that is a big .tar.gz file (as with OpenVZ Legacy) it downloaded individual rpm packages. It appears to build OS Templates on demand from current packages on-demand BUT it uses a caching system whereby it will hold on to previously downloaded packages in a cache directory somewhere under /vz/template/. If the desired OS Template doesn't exist already in /vz/template/cache/ the required packages are downloaded, a temporary ploop image made, the packages installed, and then the ploop disk image is compressed and added to /vz/template/cache as a pre-created OS Template. So the end result for my CentOS 6 container created /vz/template/cache/centos-6-x86_64.plain.ploopv2.tar.lz4. I manually downloaded an OpenVZ Legacy OS Template and placed it in /vz/template/cache but it was ignored so at this time, I do not think they are compatible / usable.
The only OS Template available at time of writing was CentOS 6 but I assume they'll eventually have all of the various Linux distros available as in the past... both rpm and deb based ones. We'll just have to wait and see.
As previously mentioned, Odin has already released the source code to vztt (Virtuozzo's OS Template build system) as well as some source files for CentOS, Debian and Ubuntu template creation. They have also admitted that coming from closed source, vztt is a bit over-complicated and not easy-to-use. They plan on changing that ASAP but help from the community would definitely be appreciated.
How about KVM VMs?
I'm currently on vacation and only have access to a laptop running Fedora 22... that I'm typing this from... and didn't want to nuke it... so I installed the bare-metal distro inside of a KVM virtual machine. I didn't really want to try nested KVM. That would definitely not have been a legitimate test of the new system... but I expect libvirtd, virsh, and virt-manager to work and behave as expected.
Conclusion
Despite the lack of perfection in this initial release Virtuozzo 7 shows a lot of promise. While it is a bit jarring coming from OpenVZ Legacy... with all of the changes... the new features... especially KVM... really show promise and I'll be watching all of the updates as they happen. There certainly is a lot of work left to do but this is definitely a good start.
I'd love to hear from other users to find out what experiences they have. If I've made any mistakes in my analysis, please correct me immediately.
Congrats Odin and OpenVZ! I only wish I had a glass of champagne and could offer up a respectable toast... and that there were others around me to clank glasses with. :)
OpenVZ Project Leader Kir Kolyshkin gave a presentation on Saturday, April 25th, 2015 at LinuxFest Northwest entitled, "OpenVZ, Virtuozzo, and Docker". I recorded it but I think my sdcard was having issues because there are a few bad spots in the recording... but it is totally watchable. Enjoy!
I'm not a big fan of proprietary software, and this is an official blog of OpenVZ, not Virtuozzo — so I haven't had any plans to tell you anything about the latter. But there is one subject I really want to share with you: why Virtuozzo is good for OpenVZ.
To begin with, Virtuozzo is a commercial product based on OpenVZ software. It adds some more value: features, GUIs, tools (and there is also Virtuozzo for Windblows). The first version of Virtuozzo was released about 6 years ago, so it is not something new. Virtuozzo costs money, and is used by big corporations for mission-critical applications. Virtuozzo customers expect it to be very stable, fast, bug-free, well documented, etc. And to sell the product successfully, those expectations must be met.
But how can all this be achieved? A lot of approaches are used: from having a top-notch development team to dedicating lots of resources to testing the software. Indeed, the Virtuozzo QA team is quite large (as well as their server farm), and there are quite a few talented people (and high-end servers) working there. Those people are doing all the bad things with the kernel, trying hard to bring it down to its knees. The majority of the tests are automated, and more and more cases are added to the extensive test suite. The general idea is to find each and every bug — and fix it before the software ships to the customer.
So, good for them, but how does that affect OpenVZ? Quite simple: OpenVZ is the core of Virtuozzo, and thus it is tested and exercised in the same manner. Not too many open source projects can boast of having such great testing and as a result such high quality.
I have to admit it: this is exactly where proprietary software helps open source software. Without Virtuozzo, OpenVZ quality would definitely be lower. A dedicated quality assurance team is always needed because it's just not appealing for developers to find a new bugs in their code — they'd rather write some more.
PS Certainly the scope of "why Virtuozzo is good for OpenVZ" is much broader than just quality: for example, OpenVZ is also feature-rich because of the same reasons.
I tried it and was able to migrate a CentOS 7 container... but the Fedora 22 one seems to be stuck in the "started" phase. It creates a /vz/private/{ctid} dir on the destination host (with the same…
The fall semester is just around the corner... so it is impossible for me to break away for a trip to Seattle. I hope one or more of you guys can blog so I can attend vicariously.
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