yes I realise about the single point of failure. Ideally of course we'd have separate physical servers for this. It's an intranet so security is less of an issue. There just seem to be advantages from running virtual machines. I'm not an expert but aren't they easier to manage, rollback and back-up? Possibly the best idea would be to have a dev and staging as virtual machines on one server and then the live instance on another.
<br><br>Interesting that a VM service would only require the RAM that Zope requires normally. You would naturally think that the VM service would take up quite a bit of RAM itself?<br><br><div><span class="gmail_quote">On 11/7/07,
<b class="gmail_sendername">knitti</b> <<a href="mailto:knitti@gmail.com">knitti@gmail.com</a>> wrote:</span><blockquote class="gmail_quote" style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; margin-left: 0.80ex; border-left-color: #cccccc; border-left-width: 1px; border-left-style: solid; padding-left: 1ex">
On 11/7/07, michael nt milne <<a href="mailto:michael.milne@gmail.com">michael.milne@gmail.com</a>> wrote:<br>> ok, so you could have two virtual machines say development and also staging<br>> which sat alongside a live production 'non virtual' instance of Zope. This
<br>> would all sit on the one physical machine. The dev and staging instances<br>> would be switched off and on as required. With enough RAM and CPU would this<br>> be a realistic set-up for a service?<br>><br>
Yes. Here are the implications:<br>- the hardware is your single point of complete failure<br>- the whole machine would share its performance among native and virtual<br>instances, so staging and development will have an impact on the production
<br>instance<br>- if you production instance gets compromised, its not far for<br>intruders to staging/development<br>- the other way round (atack on zope instance, then attack on vm to<br>reach the host)<br>is pobably not very much harder
<br><br>why don't you just run 3 zope instances on the host? If its a pure<br>zope application,<br>then they won't interfere with each other. Although you can't upgrade zope<br>idependently then, its in any case better resource-wise.
<br><br>--knitti<br></blockquote></div><br><br clear="all"><br>-- <br>michael