[CentOS] OT: Why VM?

Fri May 27 21:54:17 UTC 2011
James B. Byrne <byrnejb at harte-lyne.ca>

On Fri, May 27, 2011 14:36, Jack Bailey wrote:
> There are lots of good reasons to virtualize.
> http://www.vmware.com/virtualization/why-virtualize.html
> Jack

As it turns out, that was one of the net resources I had in mind
when I described what I found as mostly puff and smoke.  This is
what this site claims as advantages to VM:

> Top 5 Reasons to Adopt Virtualization Software

>   1. Get more out of your existing resources: Pool common
> infrastructure resources and break the legacy “one application
> to one server” model with server consolidation.

I have difficulty with this statement on so many levels that it is
hard to know where to begin.  Perhaps the most egregious is the
mindless equating of server with host.  What measurable benefits
accrue to a firm from 'breaking the legacy', whatever that means.

>   2. Reduce data center costs by reducing your physical
> infrastructure and improving your server to admin ratio:
> Fewer servers and related IT hardware means reduced real
> estate and reduced power and cooling requirements. Better
> management tools let you improve your server to admin ratio
> so personnel requirements are reduced as well.

Personally, my experience is that, if anything, running multiple
systems on a vm host measurably increases the administrative burden
per host.  For one thing, you now have multiple instances to update
and to keep secure whereas before you had one OS to worry about.  If
we had tens or hundreds or thousands of servers then yes, I can see
the benefits.  We, however, do not deal with equipment on that

>   3. Increase availability of hardware and applications for
> improved business continuity: Securely backup and migrate
> entire virtual environments with no interruption in service.
> Eliminate planned downtime and recover immediately from
> unplanned issues.

I suppose that moving VM instances as file systems provides a real
value by eliminating the setup and configuration required to get
bare metal to flash up in a usable fashion.  This is in fact the
only area that I see a real advantage to VM over bare metal

>   4. Gain operational flexibility: Respond to market changes with
> dynamic resource management, faster server provisioning and
> improved desktop and application deployment.

I have no idea how deploying VMs to a company's desktop workstations
could possibly benefit the firm.,

>   5. Improve desktop manageability and security: Deploy, manage
> and monitor secure desktop environments that users can access
> locally or remotely, with or without a network connection, on
> almost any standard desktop, laptop or tablet PC.

Again, how is this accomplished and what are the advantages over a
single OS install?  None of the above claims have anything to do
with VM per se as far as I can see.

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James B. Byrne                mailto:ByrneJB at Harte-Lyne.ca
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