/ system administration

Migration From Physical to Virtual Servers

I have not seen too many blog posts on this particular topic. It seems to be some dark art reserved for consultants. So I thought I would share some of this knowledge.

Recently the company I work for made the jump from physical boxes to virtualized architecture. We made this move to solve a number of issues, number one we were running out of storage room and fast. We had calculated that we only had three months left before we would have zero room to grow.

The next problem we had three servers clustered and synchronizing. The servers were mirrors of each other. This gave us great redundancy, but horrible utilization of resources, as well as a lot of wasted storage. We had so much duplicated data it was sickening, and every software we used to synchronize would take on the order of fifteen to thirty minutes to sync all three together, pretty amazing considering it was doing nearly 5 million files per sync. This means if a user happens to upload a file to server one it could be as much as thirty minutes before users on server three could see that file. This is unacceptable in most web environments, and was annoying to our users to say the least. Not to mention the time to sync was increasing as users added more files into the system.

So we needed a solution to cover those two main problems and would help us scale for the foreseeable future. Their were two answers we came up with, one – we could keep our server as is and purchase another physical box as a file server. This would be a bandaid measure which eventually would be out grown and beg for more drastic changes, or we could go virtual right now. We opted for the later of those options.

We had decided to go virtual, we hired consultants and assembled our architecture on paper, and give us a plan of action to execute. We hired SANplicity they were great to work with and helped us review the upgrade paths we could take.

Our final setup was.

VMware VSphere 5 Essentials Plus Kit for 3 Hosts
Dell EqualLogic FS7600 NAS Appliance – (Shared Storage Appliance)
Dell EqualLogic PS6110X 10GbE Array – 14.4TB capacity (Storage)
3 Hosts configuration – 2 procs at 2.66 ghz Hex Cores, 88 GB ram

This would allow us to scale our architecture for the next year or two and allow us wiggle room with how we configured the virtual machines, as well as allow for expansion into more VMs.

This is not the most powerful configuration we could have gone with but with the price tag for this single move coming in around 100,000 dollars. We allotted for a window of growth. Assuming we may need to revise our architecture plan with in the next year or two and technology changes as well as the business needs change. So we were conservative with this move.