Bjoern Zeeb has provided a summary regarding the completion of the funded portion of the FreeBSD Jail Based Virtualization Project:

I am happy to report that the funded parts of the FreeBSD Jail Based Virtualization project are completed. Some of the results have been shipping with 8.1-RELEASE while others are ready to be merged to HEAD.

Jails have been the well known operating system level virtualization technique in FreeBSD for over a decade. The import of Marko Zec’s network stack virtualization has introduced a new way for abstracting subsystems. As part of this project, the abstraction framework has been generalized. Together with Jamie Gritton’s flexible jail configuration syscalls, this will provide the infrastructure for, and will ease the virtualization of, further subsystems without much code duplication. The next subsystems to be virtualized will likely be SYSV/Posix IPC to help, for example, PostgreSQL users. This will probably be followed by the process namespace.

Along with the framework, debugging facilities, such as the interactive kernel debugger, have been enhanced so that every new subsystem will be able to immediately make use of these improvements without modifying a single line of code. Libjail and jls can now work on core dumps and netstat is able to query individual live network stacks attached to jails.

For the virtual network stack, work was focused on network stack teardown, a concept introduced with the network stack virtualization. The primary goal was to prototype a shutdown of the (virtual) network stacks from top to bottom, which means letting interfaces go last rather than first and still being able to cleanly shutdown TCP connections. Good progress was made, but a lot of code over the last two decades was never written in a way to be cleanly stopped. Work on this will have to continue, along with virtualizing the remaining network subsystems to allow long term stability and a leak and panic free shutdown. As a side effect, users of non-virtualized network stacks will also benefit, as other general network stack problems are identified and fixed along the way.

I am happy to see more early adopters, former OpenSolaris users, and people contributing code or reporting problems and would like to encourage people to further support this project.

My special thanks go the FreeBSD Foundation and CK Software GmbH for having sponsored this project, as well as to John Baldwin and Philip Paeps for helping with review and excellent suggestions.

The post Update on FreeBSD Jail Based Virtualization Project first appeared on FreeBSD Foundation.

We are pleased to announce that Edward Tomasz Napierala has been awarded a grant to implement resource containers and a simple per-jail resource limits mechanism.

Unlike Solaris zones, the current implementation of FreeBSD Jails does not provide per-jail resource limits. As a result, users are often forced to replace jails with other virtualization mechanisms. The goal of this project is to create a single, unified framework for controlling resource utilisation, and to use that framework to implement per-jail resource limits. In the future, the same framework might be used to implement more sophisticated resource controls, such as Hierarchical Resource Limits, or to implement mechanisms similar to AIX WLM. It could also be used to provide precise resource usage accounting for administrative or billing purposes.

“It’s great that the Foundation decided to fund this project”, Edward noted. “It will make jail-based virtualization a much better choice in many scenarios, for example for Virtual Private Server providers.”

This project will be completed December, 2010.

The post Resource Containers Project first appeared on FreeBSD Foundation.

One of the proposals selected for funding earlier this year was for jail based virtualization. Bjoern Zeeb, the developer being funded, recently provided an update on the progress of this project:

Bjoern A. Zeeb has been awarded a grant to improve FreeBSD’s jail based virtualization infrastructure and to continue to work on the virtual network stack. His employer, CK Software GmbH is matching the Foundation’s funding with hours.

FreeBSD has been well known for its jail based virtualization during the last decade. With the import of the virtual network stack, FreeBSD’s operating system level virtualization has reached a new level.

This project includes cleanup of two years of import work and development and, more notably, brings the infrastructure for a network stack teardown. Cleanly shutting down a network stack in FreeBSD will be the major challenge in the virtualization area to get the new feature to production ready quality for the 9.x release
lifecycle.

Further, the project includes generalization of the virtual network stack framework, factoring out common code. This will provide an infrastructure and will ease virtualization of further subsystems like SYSV/Posix IPC with minimal overhead. All further virtualized subsystems will immediately benefit from shared debugging facilities, an essential feature for early adopters of the new technology.

Improved jail based virtualization support, that continues to be very lightweight and as easily manageable as classic jails, will be a killer feature for the next few years. It will allow people to partition their FreeBSD server, run simulations
without racks of hardware, or provide thousands of virtual instances in hosting environments fairly easy and efficiently. While this follows the trend of green computing, it also adds to FreeBSD’s virtualization portfolio with Xen or other more heavyweight hypervisor support, which can be mixed with jails as needed.

While work in this area will have to continue, the funding for this project will end mid-July 2010.

The post Update on Jail Based Virtualization Project first appeared on FreeBSD Foundation.