Virtualization Frontier

Benefits of iSCSI over Fiber Channel

ToddMuirhead — Tue, 01 Jul 2008 16:39:00 GMT

Our upcoming chat today on benefits of iSCSI and Virtualization led me to some quick research to see what I could find. The first hit was for a Dell Whitepaper on why iSCSI is the best storage for virtualization. Turns out this is a whitepaper that I reviewed internally before it was published about a year ago.

I was a long time fibre channel user and thought that some of the points in the paper were a bit harsh. The funny thing is that reading it now I agree with it much more. The paper didn't change, but my experience in the last year with iSCSI has changed me. I really do think that iSCSI is easier and the performance concerns that I had, for the most part, don't concern me anymore. Although I must admit that I still like my CX3-80 fibre channel storage.

Todd

Wiggle Room in Deciding on a Virtualization Server

ToddMuirhead — Sat, 07 Jun 2008 15:33:00 GMT

What is the best server for virtualization? This is a question that comes up often in discussions, although it is sometimes phrased differently. It might be "How many NICs do you recommend for ESX?" or "How much RAM can you put in an R805?" or "Are blades the most power efficient server?". The really cool thing is that the answer to all of them ends up being the same - If you can tell me what you are trying to do, and the key requirements that you have, I can give you the best answer. Sometimes you need tons of RAM, sometimes you oodles of NICs, and sometimes you are looking for the best value.

We can give you some basic guidance and even provide you with reference architectures, but ultimately everybody has to customize their virtualization solution based on their needs. To provide you with the ability to be able to customize, you have to be educated about what your choices are what the ramifications are for each choice. That's what this focus topic on Selecting a Virtualiation Server has been all about. Connecting people with the information as well as each other for discussion about the process. This played out in each of the three chats that we did, and can continue on the discussion threads.

This really isn't anything new in the IT world. Almost all solutions have required a certain amount of planning and sizing that was specific for each organization. The advantage with virtualization is that there is more wiggle room to adapt and learn as you go. Because virtualization provides a layer between the VMs and the physical servers, things can be changed, modified, tuned much more easily than without virtualizaiton. If you find that a server is overloaded with too many VMs, you can use VMotion to move some to another server. If you find that you are out of capacity, you can add another server to the farm and redistribute the VMs to take advantage of the new capacity - without any downtime.

Use this community to keep the discussion going about what the best server is for virtualization - all questions around this topic are welcome. The opportunity to interact with your peers and find out why and how they made their decisions is really the best answer to a question that has a different answer for everybody.

Todd

Virtual NIC Performance

ToddMuirhead — Thu, 17 Apr 2008 15:54:00 GMT

During our regular TechTuesday webchat, a question came up about virtual NIC performance. The topic this week was Running Enterprise Apps on VMware, and one aspect of that is performance. Hywel, who has a successful SQL Server deployment on ESX, asked - why is he only getting 250 mb/s of throughput? I found a VMware blog post and a whitepaper that indicate it is possible to get much higher. Of course in real-world use through-put will be lower, but I would think that you could top 250 mb/s. I believe that the key to getting the best performance form a virtual NIC in VMware is to install the VMtools and use the VMxnet NIC.

Todd