Virtual Technology

[Billy Crook]

On Wed, Dec 22, 2010 at 21:28, Jim Herrmann <kclug at itdepends.com> wrote:
> hell of a lot cheaper?  Is there a better open source equivalent to Citrix?
> I couldn't find it with just a few minutes on Google.  NX seems like it

NX is most likely the best Free Software Citrix replacement.  They
sell some commercial components which probably handle "management" of
hordes of users.

> Xen appears to be the open source equivalent to VMWare?  Then there's KVM
> too, right?
>
> Just exploring possibilities here and trying to get my mind around the open
> source virtualization world.  Let me know what you think.

NX (and similar protocols/servers like xdmcp and vnc, and X11
forwarding) have nothing to do with virtualization.

VMWare is a company, not a program, so there is no Free Software
equivalent thereto.

The closest match to vmware server is probably kqemu because like
vmware server, kqemu does not require hardware vm support in the CPU,
and like vmware, it supports virtual guests which are not modified
specifically to support being virtualized.  AFAIK though kqemu is not
as performant as vmware server.

KVM is mostly considered to be the successor to Xen.  KVM is the
modern generic replacement for VMware server/esx in GNU+Linux systems.
 KVM does require hardware support in the CPU, but that's been
standard now for about 5 years.

You should however, consider OpenVZ if all your guests will be running
the same Linux kernel, or kqemu if emulation of other architectures is
useful, and even consider if you need to be running multiple instances
of an OS, or if all you really need is multiple server instances,
which is often significantly more efficient.