Oz No Longer

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Dorothy, along with the Tin Man, Scarecrow, and Lion, were terrified of the great and powerful Oz, until they realized it was only an illusion puppeteered by a very non-threatening man behind a curtain.

Too often, contacting tech support can be like seeking help from the wizard. In CLA, however, we take a different approach -- we enjoy talking to you!

Have general or specific questions about server infrastructure? Interested in a consultation about supporting a new research project? Work off campus frequently and prefer to schedule a specific time to meet? Connect with us in person, via phone, or in a Google Hangout.

To ensure we're ready to assist you, and so you don't have to worry about coordinating with a specific engineer, select from our calendar of appointment times:

http://z.umn.edu/a04

Learn more about Google Calendar appointment slots

Look Ma, No Passwords!

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We are finally back to the blog after a long summer hiatus. Based on your feedback, we will use the blog to post some how-to articles addressing commonly asked questions, starting with this article.

CLA-OIT's Linux terminal server, lts.cla.umn.edu, allows you to access dozens of other servers from within a single session. While the access is very convenient, it would be very inconvenient if you had to type your password every time you wanted to log in to a server. There is a very elegant, but technically complicated way, of removing passwords from the login process while still keeping logins secure.

We have documented how you can configure this for your login on lts.cla.umn.edu, as well as provided links to resources describing the same process for OSX and Windows:

Configuring Public/Private Key Authentication

Feedback about the format or content of this article? Email us at 4help@umn.edu.

On the Farm

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On August 4, our Windows Terminal Server freya will be put out to pasture and replaced by a new Windows Remote Desktop farm. What does this mean for you? Instead of having only one server to handle your Windows computing needs, we'll have three (and possibly more). More servers means more CPU cores, and more memory available for your jobs. In fact, two of the new farm servers have 64GB of RAM and 32 cores each!

When you connect to the new farm, you'll be routed automatically to one of the Remote Desktop servers. If you already have an existing session on one of the servers, you'll be reconnected to it, wherever it may be.

The new farm will have a different name: wts.umn.edu. Starting in August, connect to wts.umn.edu instead of freya.cla.umn.edu. Note that freya will be retired on August 4, at which point incoming connections will automatically be routed to the new farm.

Questions or comments? Email us at 4help@umn.edu.

News and Updates

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Recently we've been updating key applications running on our Linux and Windows servers. Read on for the major updates which include links to information about new features.

SAS

We've upgraded SAS on freya, the Windows terminal server, to version 9.3. We are still running SAS 9.2 on loki. Since loki is one of our older servers, and is already overloaded with the SPSS server software it is running, we have decided to move our SAS install to one of our new machines, apollo. This will be happening over the next few days.

Matlab

We are now running Matlab 2012a on all our Linux servers and freya. We have not recently upgraded Matlab since there has been no demand for the newer versions, but we have received requests for version 2012a and decided that it was time to move on. We have also removed some of the older versions that we've been keeping around for backwards compatibility. We have done this because we needed to make room for new software installs, and also because some older versions stopped running under current Linux versions.

Stata

Stata has been updated to version 12 on all Linux servers.

Mathematica

Mathematica has been updated to version 8 on Windows and Linux servers.

Tell Us What You Think

As you use the servers, you might notice that the "default" versions you get are different from one machine to the other. Since we do not have a fully automated method to deploy these applications yet, we might have overlooked some servers for some of the applications. If you notice something outdated or missing, on any given server, please let us know.

There are many other applications that we are running on our servers. Most of these are specialized ones that we will only update when explicitly asked. If you happen to use one of these and would like it updated, send us a request.

Virtual Servers

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Years ago when servers had just one or two processors and only a couple of gigabytes of memory, it was not very easy to run more than a couple of computing tasks at one time. If you needed a server, you had to buy your own at a substantial cost.

In recent years, computing technology has grown by leaps and bounds. While our current generation of servers can have sixteen processor cores and almost a terabyte of memory, there is almost no task big enough to require this kind of power in our environment. Even the least expensive server we can buy, for around $4,000, has twelve cores and 16GB memory.

Now virtualization has become really useful--running multiple independent servers on a single piece of hardware, under the virtualization hypervisor, offers a way to make use of all the excess power in a modern server.

Our Server Infrastructure

CLA-OIT is running more than 120 virtual servers on 10 physical servers using VMWare's technology. This saves a tremendous amount of money and makes it very easy to create new servers. While it might take weeks to choose, order, receive, and configure a new physical server, we can create a virtual server in a couple days, (or hours, if needed).

Upsides

Virtualization is a great convenience for system administrators, and wonderful news for accountants, but why might it be important to you? Imagine a research project or a class needs a single-purpose "simple" server that does not require a lot of horsepower. Spending thousands of dollars on a physical machine that will be 90% idle is not the best idea, and running server software on an office computer is even worse. Our no cost virtual server hosting service makes it easier to build prototypes, initiate pilot projects, or support classroom work that lack funding for hardware investments.

In addition to the ease and speed of creating new servers, virtualization offers great benefits in redundancy and high availability. For example, if you are using a physical server, any hardware failure means that you are dead in the water until the server is repaired. Since our virtualization environment in composed of servers working in tandem (in a cluster), a hardware failure is just an inconvenience--it is only a matter of minutes to move virtual servers that were running on a failed piece of hardware to the next available server. Over the next couple of years, we will be working to enhance this capability, so that our virtual infrastructure will be able to keep running even when the University's entire datacenter is unavailable.

Downsides

One downside of virtualization is server "sprawl," which is what happens when it is so easy to get a new server. Five years ago, when we first started our virtualization project, we had fewer than 100 servers. Today, we have more than 300--most of them virtual. Even though we tripled the number of servers we're running, we haven't tripled our staff so we must find ways to make running servers easier. Standardization and manageability have become key points for our server design. When you request a virtual server we will ask you to follow our standards, and you might have to reconsider certain decisions to fit those standards.

Requesting a Server

If you have a server-related need, we want to hear from you--even if it is about a service we aren't currently offering. While a dedicated virtual server may be the right answer, we offer many options. In any case, our staff will go through an in-depth planning process with you to ensure we find the solution that best meets your needs.

Your Input Needed: Readership Survey

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The CLA-OIT Infrastructure Team has been publishing articles about our services in a new blog for the last several weeks. We would like to get your feedback about the content we've published so far. What would you like to see moving forward? Take our brief survey to help us out.

How I Learned to Stop Worrying and Love the Server

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The CLA-OIT Unix Environment provides access to applications used for statistical analysis, including Stata, Matlab, and Mathematica along with robust, backed-up data storage for your research. On request, our system engineers can also set up shared folders for researchers who need to collaborate on projects. CLA-OIT runs several public servers that host these applications. No matter which server you log on to, you have access to all of your data--stored on our high-performance file servers, backed up daily. The screencast below explains the basics of getting access to our servers and how to work with your data.

Keeping it all together

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The most important thing we do for you is taking care of your documents and data. You've spent years collecting data, writing articles and dissertations, and you might be one hard drive crash, or stolen laptop, away from losing substantial amounts of work. CLA-OIT's storage offerings provide you with convenient, high-performance storage that you can access from anywhere in the world, with reliable backups that will protect you from most disasters.

Run, Jobs, Run!

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There are several tools available on our servers to monitor resource utilization. The most commonly used utility is top. top gives you a running snapshot of a number of different metrics on a server. In this article we highlight important metrics for you to watch for to ensure you share resources responsibly, and don't run afoul of our policies.

How Much is Too Much?

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The application servers I recently discussed are available to any account holder, without any restrictions: log in, use any program, and consume as many resources as you want. We also run some private servers, restricted to certain subsets of users, which also have no usage limit. Even though this works fairly well in practice, with everyone playing nice and getting their work done, we sometimes encounter situations where a single person is in a hurry to get something finished, and tries to do too much. Overuse by one can cause performance degradation for everyone else and may even crash the server. By knowing what to watch for you can help avoid such a situation.