We have discussed different aspects of virtualization in these previous tips tip 1, tip 2, tip 3, tip 4. In this tip we look at additional reading and resources you can use to make the most of your virtualized SQL Server enviornment.
Each previous tip tried to cover a specific step in the virtualization process. I discussed why we would want to virtualize SQL, how to plan for virtualization, and how to implement and maintain a virtual environment. It isn't feasible to cover everything but I hope I succeeded in covering enough to give you more confidence when discussing virtualization. But what does virtualization mean for DBA's? How does it change the way you work? Here are some differences I've experienced - some are positive changes while others are negative:
- Expect server sprawl. Plan for an increase in the number of SQL servers in a virtual environment.
- You will need to think hard about licensing. Coordinate your licensing plans with your VM administrators. You may want to think about consolidating SQL Servers onto a single host or host cluster. Also consider hiring a professional firm to help your company navigate the licensing confusion.
- Expect a small loss of control. You are no longer a DBA for a server. You are now a DBA for a SQL instance. Your storage team and virtualization administrators will now play a key role in maintaining your system and making key decisions. But make them earn their new found authority. If you suspect problems, lean heavily on them to fix it.
- Even though you lose some control you'll need to broaden your knowledge. Read up on virtualization concepts by researching technical whitepapers and attending vendor or community seminars on virtualization (see my list of links below)
- Take advantage of tools developed specifically for monitoring a virtual environment. Confio's IgniteVM and the vSphere client come to mind and are the ones I use on a daily basis.
- Expect the possibility of large outages due to VM tools failing. All virtual machines are virtual and are maintained by a VM management tool. What this means is if the tool goes offline then your machines will "disappear". This has happened a couple of times but recovery tends to be fairly quick with no data loss. You also may witness more connectivity issues related to the SAN. The vSphere tool actually runs on SQL Server so take good care of it.
The good news is the resources available to you have increased over the years as virtualization has become more the norm than the exception. There are a large number of people much smarter than myself who look very closely at SQL Server and virtualization and do a great job detailing the technical advantages and disadvantages. Here are few links I'm aware of and if you know of others I may have missed I would be delighted if you posted them in the comments.
- Brent Ozar - has been talking about virtualization and the SAN for a long time. He even had a recent PASS Summit session on the topic.
- Denny Cherry - has extensive thoughts on how to configure your SAN in a virtual environment. Thinking about the SAN is critical to a successful virtualization project.
- SQLOS Team - I just found this recently and it is a great resource to get you moving to other resources.
- Johathan Kehayias - a great one-stop-shopping location for addition resources.
- Confio Whitepapers - I'll also list Thomas LaRock as a resource for VM since he works for Confio is a great presenter detailing the benefits of the IgniteVM product. PASS Virtual Chapter on VM
There is a PASS chapter for virtualization. Please don't hesitate to contact Mark or David if you want to contribute.
As you probably noticed my links focus on the intersection between SQL Server and Virtualization. There are many more links and resources for virtualizing other products and also resources for better understanding virtual technology. I've talked about about some of the technical details such as CPU scheduling and I encourage you to dig further.
I'll make a educated guess where all of this is going. There will be a day when everything is virtualized - yes, even even your data warehouses, will be virtual. The cost benefits, resources savings, and efficiencies are too tempting. The technology will continue to improve so that every system, no matter how resource intensive, will be a candidate for virtualization. The cloud will be the primary architectural consideration when building out new projects. The cloud may exist outside your company or within your company. Cloud computing won't just be used for servers. You will also see a large effort to virtualize desktops. Our company is currently going through a VDI (Virtual Desktop Infrastructure) project and we could see some limited virtual desktop implementations in the next few months.
Of course it isn't all pie-in-the-sky and there are going to be some serious challenges. I think SAN speeds are still way to slow. There is the option of tiered storage that will help but the expense is too much and the management too difficult for most organizations. Licensing issues for both virtualization products and products like SQL Server may have some companies thinking twice about implementing virtual architecture. A knowledge gap also still exists and it is difficult for companies to find qualified candidates who have experience setting-up virtual infrastructures. I'm certain there are number of other obstacles and I'd be curious to here about them. I'd like to know what has prevented your company from virtualizing SQL Server or what has made your virtualization project a success or failure.
- vSphere Whitepapers - This is the link to whitepapers on vSphere. There are some interesting topics to dig through which will give a good technical foundation on virtual technology.
- Microsoft's Hyper-V - This is the link to Microsoft's Hyper-V product. Another term for implementing virtualization in-house is call "private cloud".
- Booting from VHD - Helpful article explaining how to boot from VHD for a SQL Server test or development environment.
- SQL Azure - There are number of MSSQLTips on SQL Azure. Here is a link to the all the links.
- If there are any additional vm tips you would like to see please leave a comment or contact me and I'll be happy to talk about it.
Last Update: 2011-12-29
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