[mythtv-users] OT: Virtualization

[Raymond Wagner]

On 7/4/2013 11:00 AM, jacek burghardt wrote:
> I virtualization is all about saving money an power and testing.

No. That's consolidation. You can run multiple servers on one system 
image. You can run multiple servers on isolated filesystems on one 
system image. 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.

> is incorrect is very easy to pass pci devices.

The LinuxTV driver developers would disagree with you. Many times have 
they tried to diagnose strange behavior on some user's system, only to 
discover they were attempting hardware passthrough in a virtual machine. 
Hardware drivers make certain, entirely reasonable, assumptions about 
the behavior of the hardware they are interfacing with, and attempting 
to use hardware in a virtual machine often invalidates those assumptions.

> The box also runs freepbx, pfsense, 3 x server 2012 ( domain controler, exchange server)

PFSense is a special case, as a firewall application, it would need to 
directly manage the host, or at least have its own virtualized network 
stack to control. FreePBX and most other POSIX style applications would 
otherwise be perfectly content to operated in an isolated chroot, 
completely independent of any other task on the system.

Windows is a bit different. Unlike POSIX, it hasn't had 30+ years of 
isolation and sandboxing tools like chroot, and applications fight a lot 
more. Further, you can't run Windows and POSIX applications on the same 
host, however often times, that's more a function of finding more 
appropriate tools for your operating system of choice. There are plenty 
of groupware tools to replace exchange, using industry standards like 
IMAP, WebDAV, and CalDAV to provide the same functionality. Samba really 
doesn't cut it as a replacement domain controller through.

Of course, if you are a large enough organization to need an exchange 
server, and the management capabilities of a domain controller, chances 
are you're going to have enough load on them to merit giving them their 
own physical systems, rather than putting them on an overextended box 
with a bunch of other servers.