<div class="gmail_quote">On Tue, Oct 25, 2011 at 9:36 AM, Raymond Wagner <span dir="ltr"><<a href="mailto:raymond@wagnerrp.com">raymond@wagnerrp.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im">As I keep saying over and over and over again, power savings are _not_ a</div>
feature of virtualization. Power savings is a feature of<br>
consolidation. Virtualization is for absolute isolation. MythTV,<br>
MySQL, Samba, Postfix, Dovecot, Apache, Cacti, and any number of other<br>
applications will all live happily right next to each other on the same<br>
system. In fact, since you're likely sharing the same data in Samba as<br>
you are using in MythTV, it in fact makes far less sense to run those in<br>
a virtual machine, considering one or both of them is going to have to<br>
access those local disks through a network share.<br>
<br>
The only thing mentioned there that would necessitate a virtual machine<br>
would be Windows Server. However, that questions the need for Server<br>
2k3. It's sitting in a cupboard, so you're not using it as a desktop.<br>
Were you using it for development work, you likely would have upgraded<br>
to 2k8. You're running Postfix/Dovecot, so it's not hosting Exchange.<br>
Is there no Linux alternative to whatever you're running on there?</blockquote><div><br></div><div>One of the points that seems to be glossed over here is complexity. While adding virtualization adds some level of complexity to the mix, it can also be a tool to remove it. One reason to utilize virtualization is to remove the interdependencies between bits of software. In my case, I find it much simpler to run several virtual machines, with only a few pieces of interrelated software in in each VM, rather than have one server with many unrelated pieces of software all running together. The benefit here is that I can make changes, knowing that the changes will most likely only impact the software running in the VM I am working in, rather than having to worry about breaking other unrelated software. If I need to test something, I can clone the entire VM, change a setting or two (IPs, hostnames, etc.), test my change, and know the whole thing works before having to commit the change to production, which I can do my either using the new clone, or changing the original VM. You might say that snapshots provide for reverting, but they definitely -don't- allow me to have a completely isolated instance running simultaneously.</div>
<div><br></div><div>It all comes down to how you want to slice and dice it. In my mind, and it seems in several other people's minds, the added complexity of adding virtualization is more than offset by the added simplicity (in each VM) and isolation it provides.</div>
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