On Fri, May 27, 2011 at 11:54 PM, James B. Byrne <byrnejb@xxxxxxxxxxxxx> wrote:
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.
It depends how you do this:
Many of our clients run SQL on a differen server than SMTP/IMAP/POP3 and file & print sharing - thus 3 or 4 servers. Now they can deploy 1 large server and run everying on different VM's - they still get the same security and isolation, but save some cost.
OR, they can have 2 servers with a shared SAN and have everything running on those 2 servers and have high availability. Something they probably didn't in the past in any case.
> 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
scale.
Again, this is about saving hardware, power, heat and storage. One could very easily replace a rack full of servers with just 3 or 4, or so and thus be more green - save some space, power and heat.
Effectively you still have the same amount of OS / applications to run, but you're using less hardware
> 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
installs.
> 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.,
I can provision a new VM to a client withing minutes. A server takes more like an 30minutes to an hour to get up and running.
> 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.
Well, each end user desktop could be saved as a VM to make re-installation, or "uprgrades" much easier.
--
*** E-Mail is NOT a SECURE channel ***
James B. Byrne mailto:ByrneJB@xxxxxxxxxxxxx
Harte & Lyne Limited http://www.harte-lyne.ca
9 Brockley Drive vox: +1 905 561 1241
Hamilton, Ontario fax: +1 905 561 0757
Canada L8E 3C3
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
--
Kind Regards
Rudi Ahlers
SoftDux
Website: http://www.SoftDux.com
Technical Blog: http://Blog.SoftDux.com
Office: 087 805 9573
Cell: 082 554 7532
_______________________________________________ CentOS mailing list CentOS@xxxxxxxxxx http://lists.centos.org/mailman/listinfo/centos
