Should I virtualise a single server?

[TitaniumWorm]

Dear Community,

I have a simple question here which I would like your thoughts on. I currently have a new physical server that will be used as a SQL 2008 database server.

I will be migrating my SQL2000 application databases to this server. My question is should I install ESXi locally and run the sql server as a VM or in this instance should I just use it as normal physical install. I dont plan to run any other VMs at the moment.

Would installing it as a vm have any performance impact over it than running as a physical. This serrver will also be used as a file server for users. Unfortunatly we dont have the budget for shared storage at the moment.

Would there be any advantage to this?

Many Thanks

Chris

[piaroa]

Hi there,

If it's just this one server, and you are positive that you won't add more servers in the long run, then I don't see much benefit in virtualizing. Also, with a single ESXi instance (no vCenter), you won't have any of the features such as HA, vMotion, etc.

I could think of snapshots, performance charts, and other things as "benefits", but I'm not sure if those are actually worth the effort. Running your workload as a VM, you could see a small performance penalty of 1-3% in most cases.

[sergeadam]

If you have no other ESX hosts, it may not make a lot of sense. I've done 1:1 virtualization in the context of greater projects, maily to keep backups constant.

OTOH, if you also want to use that server as a file server, you have just made some case for virtualization, you may then want to create a VM for SQL and a separate VM for file serving. 

[msatya]

i dont think ,virtualise come to role when lot of hardware need to procure .

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please award points if you see fit.Thanks

[VIrtuallyJason]

How busy do you anticipate that SQL server is going to be?  As the above poster noted, there is a small performance penalty for virtualization, however you gain much in terms of flexibility.  Here’s how I see it:

Drawbacks:

* 1% to 3% overhead

* Complexity (rather than managing a simple Windows box, you need to be at least marginally aware of networking and the ESX Host)

Benefits:

* Snapshots (moment in time rollback capability in case of problems during maintenance)

* Image level backups/restores (restore the working OS + Data rather than restoring data into a working OS)

* Future growth (when you have the ability to provision a new server for just the cost of the OS license, use cases tend to pop up)

* Easy and accurate test environment (just clone the server and keep the clone on an isolated network – now you have a perfect replica of the production system that you can use for testing purposes).

If those benefits look appealing to you and your environment can accommodate the drawbacks (the complexity is only marginal and the average server is less than 10% utilized so the performance penalty is negligible as well), I’d say go for it.  Even if you aren’t going to see a lot of benefit now, it will position you better for the future.  I think that the industry has firmly established that virtualization is the future*.

*Some (myself included) would argue that virtualization is the present, but that’s beside the point.

[AKostur]

IMHO, yes.   As others have mentioned, there is a virtualization "penalty" to pay in order to virtualize a server.  However, on the flip side you get a bunch of the benefits of virtualization such as the ability to snapshot your server.  The one extra case that hasn't been mentioned yet is server migration.  When it comes time to move the SQL database to a bigger server, it's easier to just copy over the VM instead of having to potentially reinstall the OS on a newer/bigger server.   (And if you eventually expand to a full vSphere deployment, vMotion comes into play where it can move the VM without VM downtime....)

[zachweed]

As far as any advantages to this, I truly cannot name one. In my honest opinion ( looking at the grand scheme of things ) there are really not enough advantages to virtualizing any one server at a time. As far as performance goes, will you notice a significant difference in performance that truly makes it beneficial to invest in virtualization? No.

[Randomz]

I have a virtualised single server for two good reasons already mentioned above.

Hardware independance and image backups.

I copy image backups to a spare PC that is normally powered off making it safe from attacks, power spikes etc.

If the server has a hardware failure, I simply start the spare PC, start the virtual machine, and be back up and running within minutes.