Westminster College needed to move from 32 GB of RAM to 48 GB of RAM in each of its three vSphere hosts. Scott Lowe runs through their upgrade options, explains why he chose their solution, and asks what you would have done.
Technology equipment has a relatively short lifespan, measuring anywhere from three to five years depending on the organization. At Westminster College, we basically stick to that range, but sometimes we have situations in which we need to make a change mid-course, and we have to take a hard look at whether it makes more sense to upgrade a component or replace it altogether.
We recently needed to move from 32 GB of RAM to 48 GB of RAM in each of our three vSphere hosts. We've moved more services than originally anticipated to the virtualization platform, and we also decided to start moving our Microsoft enterprise applications (Exchange, SharePoint, and SQL Server) to vSphere as we migrate to Exchange 2010, SharePoint 2010, and SQL Server 2008 R2. For our original goals, 32 GB per host was more than sufficient.
Our vSphere hosts consist of Dell PowerEdge M600 blades, so I stated looking at options for what it would take to upgrade these systems to 48 GB of RAM. Unfortunately, since all of the RAM sockets in each server were already filled, I needed to rip and replace all of the RAM. Here are the upgrade options I considered:
- Buying RAM from Dell: I quickly changed my mind about this course of action when I saw that it was very, very expensive.
- Trying third-party alternatives, such as Crucial: I was concerned about the impact that the third-party memory would have on my system warranty. I looked at pricing, and I found that I could replace the RAM in the machine with enough modules to get me to 48 GB, but at a cost of around $3,900, which was more than I budgeted.
- Adding an additional vSphere host to the resource pool: vSphere licenses aren't inexpensive, particularly when you figure in annual maintenance costs. In reviewing our performance logs, I've found that we're barely touching the processing resources included in the pool, but we do tax the RAM resources.
- Checking out Dell's refurbished outlet store: I was stunned by what I saw. I managed to pick up a dual quad core M610 blade (the next generation of our current blade) with Xeon 5500 series processors, 48 GB of RAM, RAID, and everything else we needed for a paltry $2,500. The decision became an easy one, particularly since I'm a big believer in Dell's refurbished product. One drawback to the outlet store is that you can't customize the machine configurations. I have been looking for another deal like the one I found, but one hasn't come around yet. So, I contacted my Dell sales rep for a quote on two more blades identical to the one I had just picked up, and we're able to get them for just over $4,000 each, or around $100 more than just buying third-party RAM. If I go this route, we'll be able to move to 48 GB RAM in each host and move to Xeon 5500 series processors, which provide significantly more capability in the virtualization arena. And, we'll be able to do it for less money than we would have spent by simply buying RAM and upgrading the existing equipment. If I had upgraded the RAM without considering alternative options, I would have ended up spending more money and not being positioned as well from a technology perspective.
- Adding the new server to the existing vSphere server pool rather than replacing the servers: In this case, we'd need to purchase an additional vSphere dual socket license along with service and support. At academic pricing, this isn't horribly expensive, but it is an additional annual expense. One more benefit is that the loss of a single host would have less impact. Although we can currently withstand the loss of a single host and the virtual machines move to other hosts, that fourth machine gives us a little more breathing room.
- Replacing one of the servers with the new $2,500 unit and then seeing where we are before I buy anything else: Although I'm worried that we might push resource limits a bit with this option, it's still a possible choice.
What would you have done?
If you had been in my shoes, which option would you have chosen? Take the poll to let me know.
I decided to add the new server to the existing resource pool and buy another vSphere license to bring us to four vSphere hosts. Although we don't currently need the processing power, adding a single server with 48 GB of RAM has the same overall RAM effect as upgrading/replacing each of our current 32 GB models with 48 GB varieties (16 GB difference in RAM in each x three servers = 48 GB). On top of that, we get the additional node in our vMotion cluster. Further, as we continue to virtualize significant applications, we will have more wiggle room. Finally, from a cost perspective, our vSphere academic licensing, even with service and support over the life of the server, will be less than buying two new $4,000 servers.