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Omni Tutorial


  1. Download and install VirtualBox on your machine, we have tested versions 4.1.12
    • If your computer runs Ubuntu 10.04 which comes with VirtualBox 3.1.6_OSE, please download the latest version of VirtualBox.
  2. Download the VM image
  3. Run VirtualBox and Import Appliance (File->Import Appliance), accept the default settings for the VM.
    • If you are using a FAT32 filesystem you will NOT be able to load the image.
  4. Start the VM and log in
  5. Change the default password, on the task bar on the top, click on the right on the user 'geni', and choose the Change Password button.
  6. Verify that the VM has connectivity. Start Firefox (shortcut on the top bar) and try to load Google. If you can't reach any website, restore VM's Network connection.
    • On the far right on the top bar, there is the network icon (two opposite facing arrows).
    • Click that icon and choose 'Auto eth0'.
    • Try loading the webpage again.

Useful Tips

  • You can copy-paste between the host and the guest VM.
  • In the terminal within the VM, use Ctrl-Shift-C to copy and Ctrl-Shift-V to paste.
  • vim and emacs editors are installed on the VM, so feel free to use them for editing your files.
  • To replace a pattern within the file:
    • If you are using vim, while in command mode, type:
      And press 'y' for the instances of the pattern you want replaced, 'n' otherwise.
    • If you are using emacs, press Alt-x and then type:
      and press ENTER. Enter the pattern to be replaced, press ENTER, enter the text you want to replace it with and press ENTER. Press 'y' for the instances of the pattern you want replaced, 'n' otherwise.
  • If you want to have a shared folder between your machine and the VM so that it's easier to transfer files during the tutorial, you have to do this before starting the VM. Follow these instructions
  • If you get an error running Omni, look at the troubleshoot page for help.
  • rspeclint

1. Using Omni

1a. Configure Omni

In order to configure Flack, you needed to login to your account in Emulab and instruct Flack to load your user information (certificate and public keys). For Omni we need to do something similar. Omni uses a configuration file, and there is a script that will automatically generate the file with some default options and place it in the default place of ~/.gcf/.

Go back to your browser, and go to the Emulan tab. On the left of your screen, there should be a link "Download your cert". Click on that and select the option about downloading as a pem file. Save this page under ~/.ssl/geni_cert.pem.

Open a terminal window and type :

This should configure your Omni, with your downloaded certificate and an ssh key pair for logging in to the nodes.

Open the file ~/.gcf/omni_config using either vim or emacs. Close to the top of the file you will see two parameters called default_cf and users. Your username should be at least listed in the user section. Look for the sections in the file that are named [pgeni] and [gpousr##]. In the pgeni section you configure Omni to use your personal information. The cert and the key attribute point to files that we have manually downloaded from This is equivalent to the Download action of Flack.

In the [gpousr##] section, the information need for logging-in to reserved compute resources are provided. It includes you unique URN and a public key that would be uploaded to the hosts that you will reserve during the tutorial.

Another interesting section to look at is the [aggregate-nicknames] sections. Flack already knows the URL for all the AMs and present you a list of AMs to choose from using a short, descriptive name. In Omni a user is required to pass the URL for each call to the GENI AM API. In this section the user get a chance to provide short descriptive names to the URLs that are easier to memorize and use.

1b. Clear the passphrase from your cert

When you first logged in to Flack, you had to type your passphrase (password). Flack cashes this information and re-uses it for the duration of the session. Omni will ask you for the phrase multiple times per command. To save time during the tutorial, we are going to remove the passphrase from your cert. There is a script to clear your passphrase. Run : 

Use the same password as in Flack.

Verify that you have the necessary credential and key files

ls ~/.ssh ~/.ssl

The output looks like :

geni@geni-vm:~$ ls ~/.ssh ~/.ssl
config  geni_key

geni_cert_enc.pem  geni_cert.pem{
geni_cert.pem Cleartext certificate, i.e. does not require any passphrase
geni_cert_enc.pem Encrypted certificate
geni_key The private key that gpousr25 would use to login to the nodes The corresponding public key that gpousr25 will ask to be loaded to the nodes

1c. Test Omni setup

In order to test that our configuration is correct, you can issue a getversion command. For this step we have used PlanetLab's AM, but you can use any Aggregate Manager(AM). getversion -a

Or equivalently using the PlanetLab nickname: getversion -a plc

For the rest of the tutorial we are going to use aggregate nicknames.

1d. Omni Commands

Listresources in Omni

Flack goes behind the scenes and call listresources for the AMs that you chose, and draws the resources in a map. In Omni in order to see what is available in each AM you will have to manually invoke listresources. Invoke listresources on utah's ProtoGENI cluster getversion -a pg-utah -o

The -o option will save the output to a file. The filename is chosen by Omni and printed as part of the output. For user gpousr25 this will look like :

Listmyslices in Omni

Both Flack and Omni can see all the slices that are created by a user. In Flack there is a list of slices under the user on the left side of the window. In order to see your active slices with Omni, you will have to use the listmyslices command. listmyslices gpousr##

For user gpousr25, this would look like :

Omni Scripting

After reserving the nodes, you are ready to login. When reserving PlanetLab resources, using a ProtoGENI clearinghouse, the login name that should be used to access the nodes is 'not' the username. The login is listed as part of the sliverstatus call. For common functionality like this that is expected to be used often, omni gives you the capability of writing scripts and including omni as a library. Under the /home/geni/gcf directory there is a folder 'examples' that includes example python scripts that use Omni. One script that is available is the script that will return the exact command for logging-in to your nodes.

readyToLogin -a <AM_NICKNAME> sliceomni##

The script will return the actual command that you would need to use for logging in.

For gpousr21 the script would return :

Aggregate [] has a PlanetLab sliver.'s pl_boot_state is: 
Login using:
  xterm -e ssh -i ./ssh/geni_key &


Note: If your hosts are in Georgia Tech you would need to use the connection through ops. To do that run

xterm -e ssh -i ssh/geni_key -F ssh/config pgenigpolabbbncom_gposlice##@<hostname> &

For gpousr21 that would be :

xterm -e ssh -i ssh/geni_key -F ssh/config pgenigpolabbbncom_gposlice21@bain &

2. Sending IP traffic

2a. Login to VM@Utah

2b. Ping VM@Kentucky

2c. Enable IP forwarding at PC@Utah

3. Sending Layer 2 traffic

3a. Login to VM@Utah

3b. Ping Server

3c. Enable Layer 2 forwarding at PC@Utah

4. Cleanup resources

Although all your reservations, have expiration times, its always good practice to release the resources after your experiment is over to make them available to other experimenters.

Deletesliver with Omni

For each createsliver that you have run, you will need to run deletesliver to release the resources deletesliver -a <AM URL> sliceomni## 

You can not delete your slice. Although this will be cleaned up when it expires, it should be an empty container and thus does not hold up any resources.

Congratulations, you have finished the tutorial! Now you are ready to design and run your own experiments. Don't hesitate to email us with any questions you might have.

5. Fill out the tutorial survey

We love to hear what you think so that we can improve the tutorials in the future. Please complete the online survey and get a temporary GENI tatoo!

6. Get Your Own Account

The accounts, that you used in the above steps will be deactivated after the tutorial. If you do not already have an account at GPO's ProtoGENI cluster, you should get your own account so that you can further experiment with GENI.

If you would like to run your own experiments in this infrastructure, please contact us at to get a permanent account. Look at the Omni Configuration page about how to configure your Omni with your personal info.

AM URL Table

AM Nickname URL
Utah's ProtoGENI pg-utah
Kentucky's ProtoGENI pg-ky
PlanetLab plc
GPO's ProtoGENI pg-gpo

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