Considering FreeBSD Jails

The listed benefits of jails also apply to linux containers (and solaris "zones"). We're going for linux containers in a big way here at $BIG_CORP with the commercial virtuozzo product, and at consulting gigs on the side we're using openvz, the open source but fully capable counterpart of virtuozzo.

Unlike a traditional VM (vmware, xen, kvm, virtualbox), there is no emulation of hardware, nor a kernel for each virtual machine, only isolation of processes into groups which comprise lightweight virtual machines, thus overhead is virtually zero, and essentially native performance can be achieved from each container (the laws of physics still apply though)

Having a single kernel image which powers the base host as well as all of the containers means that you only have to upgrade one kernel (and with ksplice that can be done while all machines are running and in service). The only potential drawback is that only one OS can be run.

Although you can run various distros in the containers (debian, fedora, redhat, sles, opensuse, centos) on a host os running rhel, centos, sles, etc, it has to run on a linux kernel, so microsoft windows could not run on such a host. For some people that could be viewed as a problem, but I consider it a major benefit.

Herzeleid: The one below sounded as an interesting research project. I once met its developer. Not for use at big companies, but I'd say a must read if you're interested in the topic. Not sure of its status, but anyway;

http://erlug.linux.it/linuxday/2008/contrib/8_linuxday2008.v...

ed: Found out it's not developed anymore since 2007, so apart from some cool ideas there's not much for the enterprise to find over there.

I took a look at the paper and it is interesting - I'll circle back for a closer look later.

I never really understood jails in FreeBSD. I need something easier/more intuitive.