[mythtv-users] OT: Virtualization

[Fredrik Hallgårde]

>
>
>     On Thu, Jul 4, 2013 at 10:42 AM, Raymond Wagner
>     <raymond at wagnerrp.com <mailto:raymond at wagnerrp.com>> wrote:
>
<snip>
>
>         You can run multiple servers on independent system images
>         running in virtual machines.
>
>         The feature set of virtualization necessarily encompasses many
>         of the behaviors users are looking for, but full machine
>         virtualization is not a necessary, nor even a desired, aspect
>         of providing those behaviors.
>
TL;DR; - To each their own...

As Raymond points out there are several alternatives to full machine 
virtualization, but for running independent system images a hypervisor 
of some sort (Xen, Vmware *, KVM, Virtualbox) is typically needed/useful.

Enterprise use of virtualization is typically for the reasons listed 
earlier (high availability, sandboxing etc). But also as a means to 
quickly consolidate different systems where the time to sort out if the 
libraries required by one application can be used with the same kernel 
as other libraries required by another application by far would outweigh 
the cost of wasted hardware resources. (Yes, hardware resources are 
wasted for every unnecessary system image)

My choice is to use virtualization (ESXi 5.0*) to allow me to run 
several instances of mythtv and other  servers (some (but not all) on 
different kernels, distributions and mythtv versions) as well as a few 
"appliances" installed as iso or packaged virtual machines (e.g. 
vortexbox which auto-rips anything put in the dvd/cd-rom) including a 
few non-linux (e.g. opensolaris). All in a single physical box = high WAF.
The benefits (time!) clearly outweigh the drawbacks.

Drawbacks that I have encountered and anyone trying this should be aware 
of include:
1. If using Vmware ESXi, make sure you use 5.0 (with updates) unless new 
patches to 5.1 fixes usb and pci passthrough
2. Different usb-chipsets handle usb-passthrough with different ability, 
I pass two usb-tuners (Nova T 500 which is a USB-hub with two soldered 
USB-devices on a PCI-card) without issues but have seen PSOD when trying 
5, others have failed to have more than one...
3. Raw Device Mapping (RDM) in physical mode is required to read SMART info

Virtualization is not an end to itself, it is a tool to accomplish one 
or more things and for many things it may not be the *best* tool - but 
the best tool may require additional resources (e.g. time).

my 2c

Fredrik
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.mythtv.org/pipermail/mythtv-users/attachments/20130704/4e300808/attachment-0001.html>