Getting started with the hive

Logging into the hive

Login to the mindhive cluster is based on a local LDAP authentication system. If you do not already have an account, see Mark Pearrow in room 46-1171 to get one.

There are currently six (6) login computers - through You can feel free to log into any of them, though you might want to check out the load on each to see which is the least-loaded one. You can just look at the little "cluster load" widget on this web site's home page to see the load on each machine.

The various versions of Microsoft Windows (XP, Vista) do not have a native SSH application installed. However, you can obtain SecureCRT from the MIT Software Distribution web site - . NOTE: MIT Web certificates are required to download the software. You can learn more about, and get web certificates, at .

Remote Access Using X11

Many of the applications you will likely use have significant visual interface components, which cannot be used over just an SSH connection. However, you can cause to send its graphical output to your own desktop or notebook computer via X11. In general,. the way to make this work is to ensure that X11 is installed on your system.

Most GNU/Linux distributions have this preinstalled. The most recent version of OS X, 10.5 a.k.a. "Leopard" comes with it installed by default, but earlier versions include it as an optional install. Microsoft Windows does not have any built-in X11 capability, but you can install XWin32 from the MIT Software Download site, .

Remote Access using VNC

If you prefer having an entire virtual desktop from the remote system (e.g. displayed on your local workstation, you can use VNC to connect.

Step 1: Obtain RealVNC Viewer.

You will need to download the trial version of RealVNC Enterprise edition and a trial license from the following links:

This will install the free RealVNC viewer, which is the part you care about. The trial license won't be used for anything other than the installation.

Step 2: Create VNC session.

Next, you'll need to log into the remote node (e.g., and start up an Xvnc process. Here's how to do it.

  1. From a terminal prompt (Linux, OS X) or from an SSH client application (Windows), log into
  2. Run the command vncserver. If this is your first time to do so, you will be prompted to create a password - remember this password, as you'll need it to connect from now on.
  3. Assuming that there are no errors, the vncserver command will exit and tell you a virtual terminal name - e.g., ba1:23. Take note of this name/number, as you'll need it in the next step.

Step 3: Connect with RealVNC Viewer.

Next, you should launch RealVNC Viewer, make some adjustments to the default preferences, and connect to the virtual terminal you created in the previous step.

  1. Launch RealVNC Viewer.
  2. Click on the "Options" button.
  3. Under the "Colour" tab, select "Full Colour" - otherwise, things will look a little funky and pink when you get a desktop
  4. Optionally, under the "Scaling" tab, you might want to enable scaling to fit the window (and preserve the aspect ratio). All this does is let you grow or shrink the size of the desktop on your screen. Note that it does not actually affect the native resolution of the session, so if you increase the size of the window, the desktop will look pixelated.
  5. In the main connection window, type in the terminal name you got previously, into the "Server:" blank, and leave the encryption to "Let Server Choose". Click "Connect".
Figure 1: Initial dialog - type in the hostname and virtual desktop number. Figure 2: Select "Full Colour"

You will now be connected to the virtual desktop on the server, and you can run applications and operate as if you were sitting right in front of the actual machine.

Figure 3: Optionally, select scaling.

Remote Access using NX Client

This is currently my favorite means of graphical remote access, though your mileage may vary. Each compute node can currently handle 10 concurrent connections from NX Clients. To get started, you need to download the appropriate client for your operating system

Once you've installed NX Client, you need to set up a connection profile. This just means entering a name for the connection (can be anything, but I suggest using the hostname of the remote computer, e.g., as well as the remote hostname (probably the same as the connection name, e.g.,

Note that there is a slider that lets you choose the sort of network connection you have. I tend to find that for desktops that are on MITNet, the "LAN" option gives best results, while wireless connections of any sort or wired connections from off-campus tend to do better with the "WAN" setting. If you are on a really slow connection, you might need to ratchet this setting down to find an optimum balance between snazziness and function.

Next, you need to set up your Desktop session to use Gnome, instead of the default KDE (KDE is not currently installed on the cluster). Just select Gnome from the drop-down box as seen in the following figure.

Now you will get a login prompt; use your regular hive username and password.

If you're running Microsoft Windows, you'll probably need to answer a bunch of annoying messages about unblocking nxssh and other apps.

The very first time you connect to this host, you'll probably also be prompted to trust the remote site's key.

After all that, you'll be set. Once you connect, you'll get a standard Gnome desktop. Note that NX works a little differently from VNC, in that you don't tend to run tons of tunnels at once - in fact, if you try to connect to a host where you already have a desktop open, your previously-open client session will close and you'll be connected to your existing desktop. This is meant to be a feature, not a bug.

vnc1.png28.17 KB
vnc2.png37.1 KB
vnc3.png35.22 KB
nx1.png19.62 KB
nx2.png21.48 KB
nx3.png10.39 KB
nx4.png7.36 KB
nx5.png16.79 KB