To Virtualize or not to virtualize, that is the question

So lately, I have been getting more familiar and putting VMware into production at our sites.  With all of the benefits of VM's I am curious as to what downfalls there are?

For instance, having a VM makes it easy to take snapshots for patching, moving or migrating to new machines by just moving the system disks, and of course the ability to run a couple of servers off one box.

Am I missing something by having everything entirely running as VM's?  I simply think the fact that backing up the disks and having the ability to run them on a new machine is the easiest form of Bare Metal Restore there is.  Booting them to different devices is never as much of a headache as when trying to migrate a physical server to a new box.

If anyone has any caveats, please share. Thanks!
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

I have been using VMWare ESX for several years in our production envirnment.  One of the strengths is also something to be careful about.  It is very easy to add new servers in a virtual environment.  Being able to add new servers without needing to add additional hardware is a huge plus.  

However, you will need to be careful to fall fall prey to server sprawl.  If you are not paying attention, you can fill up your hosts with new VMs.  This can cause problems with licensing for the OS, and using all of the spare capacity of your hosts.  If you have no spare capacity, then you will not be able to vmotion your VMs from a failed host.  This will prevent your high availibility expectations from being met.  Also, if you have used all your spare capacity with VMs of questionable value, then you will not be able to add another VM for an important project.  This could put that project behind schedule while waiting for additional hardware to be purchased and installed.

You could also be tempted to use your production system for testing servers.  You will need to take care to be sure to isolate your test systems/networks from your production systems.  You don't want a test server using all of your I/O and affect your production servers.

All in all, virtualizing your production environment is a great boon to IT departments the world over.  You just have to pay attention to what you do with the system and to not go overboard.
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
DR is easier with virtualisation.

Biggest downfall is the single point of failure, all eggs in one basket scenario.

Most haveva single SAN, what do you do it it fails!

Design out the single point of failure and you will be fine.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Agreed about single points of failure.  You don't want dozens of servers failing because one power supply goes out.

Spend the extra money to have redundant systems.  It will still cost less than buying all of the hardware for stand alone servers anyway.

Make sure you have enough spare capacity built in to survive the failure of any single point.  If you can't afford multiple SANs, then you can still configure your SAN with redundant power supplies, controllers, RAID w/ hot spares, network connectivity, etc.
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
It does not matter if you have good quality SANs, last year we had 8 Clients SAN fail!

And one SAN was an HP EVA cost £250k, design in good resilience, DR. Design out the simgle points of failure, design and test DR, Invoke DR and test.

One business out for 18 hours until recovery, this is the scary side of virtualisation.

Use VSA technology with replicated volumes, e.g. HP Lefthand etc
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.