Kevin's Blog Photography, technology, and whatever else


Green Data Center

Having been in the IT world for over a decade now I have learned many things.  Technology changes, needs change, requirements change, but one of the constants has been that IT is a resource hog on just about every level.  You need lots of people, lots of time, lots of money, and lots of energy to keep even a modest IT Infrastructure running.

With the current rush for energy efficiency a lot of focus has been placed on data centers and the energy they consume, and a major push has started to make the Data Center consume less.  I've been hearing "Green Data Center" lately. I was very interested when we got an invitation to tour a local hosting provider's new facility that they were building.

We first got the tour of their existing facility and the efforts they have made there, and we then got a tour of the new building and all the advancements that they had built in to increase efficiency.

The existing facility was built many years ago as a small server room that was initially intended to be in house gear.  As time went on customers asked to house their server there and the data center was born.  It did not have raised floor, and as such all the HVAC was exposed with all the hot and cold air co-mingled.  Over the last year they took on a "Hot Aisle Isolation" project which they say has increased the efficiency of the HVAC.  This project consists of  adding Plexiglas walls between the racks that separate the aisles into zones.  In this way you can flood the front side of all your racks with just cold air, and have just the hot air at the rear of the racks.  This allows you to have the HVAC return only handling hot air which makes the system a whole lot more effective and increases efficiency.

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DIY Solar Power Setup – Part 1

I've been interested solar power for a few years now.  I found the technology fascinating and the applications nearly limitless.  Ideally I could have a system that would power my house, and tie into the electrical grid if there was energy above our needs.  Some former neighbors of ours who now live in Arizona had a $7 electricity bill one month this fall.  Wouldn't that be nice!?  I've also read articles about people down south that have thousands of dollars in credit from the utility for the surplus energy they have fed into the grid.  Unfortunately, the bottom line purchase price shows that a system of any real value can cost anywhere from $10,000 to $30,000+ depending on your needs and what you wand to do.  I'm not interested in taking out a Home Equity Loan to get solar into my house so this size setup is not possible.

Another option that is more within my budget is a small solar setup.   I found this interesting as eventually our family would like to get an RV, and adding solar to an RV can greatly extend the battery power and help limit the need to run a generator as much.  This type of setup has been in use for years and has proven to be highly effective.  Unfortunately we do not have an RV yet, so that wasn't very useful!

Still struggling for justification to fiddle around, I decided that I could build a small setup to power my HAM radio.  This would allow me to run my on my primary power source even if the power from the grid is off during an emergency.  The solar panel will keep my batteries charged while not in use, and hopefully replenish the juice quickly when needed.  I don't use the HAM all that much, so there would hopefully be some excess power to experiment with.

The design of small solar systems can vary greatly depending on the application.  Often they consist of a few solar panels, a solar charge controller, some array of batteries for storage, and some kind of power inverter to run the standard household appliances.   In my case an  inverter was not required as the HAM radio run on standard 12v DC.  This could be added for additional flexibility at any time though.

After months of debating I decided to start designing and piecing together a setup.  I started with two 6v deep cycle batteries run in series to get the standard 12v DC.  This would allow me to run my radio on the batteries right away while charging them with standard charging equipment until the rest of the solar was in place.  Selecting the size and type of battery that is right for you is not an easy decision.  It took a great deal of research to decide on what I ended up with, and even now I'm still not certain I'll be 100% satisfied!

Two 6v Crown batteries run in series for 12v DC.


In a forthcoming post I will talk about the solar panel and charge controller as well as the hardware to interconnect everything.  Then onto the build and hopefully a working system!

UPDATE: DIY Solar Results post here!

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VMWare Data Recovery storage limitation

We've been using VDR for a while now evaluating if it would work in our environment.  On the whole it is a pretty solid product for a v1 release.  While doing our initial evaluation and going through the documentation we noticed that it was called out that having the VDR storage on a CIFS volume that was larger than 500gb would cause 'performance issues'.  We wanted to user CIFS over a local VMDK so that we could have the data be outside our data center in the event we were in a DR situation.

Knowing this, for a variety of reasons,  we chose to use a CIFS share that was slightly larger than 500gb. (1.5tb, I know not even close to 500g!)  The documentation never said, DO NOT DO IT or anything like that!  They did not indicate that anything over 500g was not supported.

Well, I'm writing to tell you that anything 'significantly' over 500g volume size is NOT SUPPORTED.  By which I mean VMWare Support will not help you.  I know because they told me they could not help me.  The senior support guy for the Americas 'laughed and walked away' when told how big the volume is.

In our experience the app became completely unstable and unusable.  Backups were not being processed as expected, the interface would hang and freeze and we would have to restart the VIC app.  I guess in my mind 'performance issues' meant that the backups would slow and take longer to complete.  Alas, I suppose that could mean anything.

My feeling was that you could get away with something in the 600-700g range, but beyond that they will send you on your way.

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