Blog Posts

During last week's chat the we discussed ESXi licensing and features. In the features portion of the discussion flakrat asked if it was possible to setup two ESXi servers with shared storage to be able to do a manual fail-over of a VM between the two servers. I was able to create this setup and confirm that it works. Read on for details.

The setup that I used to test was two PowerEdge R805 servers with ESXi Update 2 refresh installed on the hard drive. This was the currently available "free" ESXi installable from VMware's web site. To install I used the Dell Remote Access Card (DRAC) virtual media capability to boot from the ESXi ISO I downloaded. I selected the local hard disk as the location to install and let it complete. Once installed, I used the ESXi configuration to set the password, IP, gateway, and hostname for each server. I then installed the Virtual Infrastructure client on a windows server and used that to manage each of the R805 servers individually.

For shared storage I used a PowerVault MD3000i iSCSI storage array. I enabled the iSCSI software initiator on each server and discovered the the MD3000i. On server A, I created a VMFS partition and created a new VM called VMTest1. I installed Windows Server 2008 64-bit Enterprise Edition. After install completed I shutdown the VM on server A. I then went to server B and rescanned the storage adapters. It found the new VMFS partition on the shared iSCSI LUN. I created a VM using the same settings as I had on Server A including the same virutal hard disk file. I then boot the VM successfully.

The most interesting part of this test was to verify that the cluster file system of VMFS was still working without Virtual Center in the picture. So with the VM still running on Server B, I tried to start it on Server A - and I got an error message that the file was in use by another server. This was great because it showed that it would not be possible to run the VM at the same time on both servers.

We will chat more about this on today's chat - ESX and ESXi.

Todd

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

For the past three weeks, we at the Dell TechCenter have been focused on the decoder ring for systems management. Starting today we are going to tell you what the best server is for virtualization. The reason it is going to take three weeks is that the answer for everybody is different. So we are going to talk about key factors, advantages of one type of server over another, and learn from the decisions and thought processes of each other. We are simply hosting the conversation and I do not have a "favorite server" -- although I must admit that I used to lean heavily towards 2-socket servers.

The decision for most seems to come down to 2-socket, 4-socket, or blades servers. I hope that we end up expanding the conversation and talk about lots of other possibilities including storage options, hypervisor options, and who knows what else.

In order to get things going are going to have some chat sessions, there is a topic home page, and a server selection matrix page to specifically lay out the facts about each type of server. I've started the page off with 2-socket, 4-socket, and blades as server categories with some basic tech specs and advantages for each type. This page will grow as additional pros, cons, and others ideas come up.

Todd

I leave for vacation for a few days and all kinds of cool stuff is announced (although I did make it into the office a couple of times while on the beach). What I think is a really great server for virtualization is now on the website where you can configure and order it. The new PowerEdge r805 is not just a new version of the 2950 or 2970. It was designed with virtualization in mind and has the features to back it up. It has 16 memory DIMM slots, 4 embedded NICs, plus four more PCI slots, and is still only 2U.

I put together a couple of configurations on the website and the price for an r805 system with two top bin quad-core processors and 64 GB of RAM seems like a great deal to me. I guess that I'm still thinking about some of the old PowerEdge 8450 8-way servers that I tested with back in the day with a list price of over 50K, which was a good deal at the time.

Todd