[mythtv-users] Multiple backends

[Raymond Wagner]

On 3/20/2011 11:50, Raymond Wagner wrote:
> On 3/20/2011 11:50, Raymond Wagner wrote:
>> Last, don't use a VM.  There is very little reason for any home user to
>> need to use them.
> On that I disagree. YMMV, but it allows segregation of functions
> which makes admin a lot easier. On my server I have three different
> incarnations of Debian running. For some stuff I need an up to date
> version - so it's got Squeeze. For other stuff, it's too much hassle
> at the moment to upgrade everything, and that's still running Sarge.
> And then I've got stuff in between running Lenny.

On that I disagree.  You would be just as well off running another 
install in a chroot.  All the same file and library isolation as a 
virtual machine, with none of the overhead.  If you need network 
isolation, well then there are security containers that can handle that 
without the overhead of full virtualization.

A home user wouldn't care about any of the HA and live migration 
capabilities of enterprise VM software, so the only remaining thing it 
would offer is the ability to run multiple kernels and system 
architectures simultaneously.  Considering no VM is going to provide 
much meaningful hardware access, there's no need to run multiple 
kernels.  That same userspace which runs on a 2.6.18 RHEL5 kernel would 
run just as well on a modern 2.6.38 kernel in a chroot.

Virtual machines are the 20lb sledge of system management.  It will get 
the job done, but in nearly all situations, it is wholly unnecessary, 
and overkill for the task.  It should not be the only tool in your 
toolbox.  There are others that are better suited.  I'll go a step 
further and say that on a low (under)powered server, and especially one 
that is likely to not have hardware virtualization extensions, you 
absolutely do not want to be running VMs.