Skip to main content

Latest Tweets

  • New post: High-performance computing for Economists 2017 edition
    about 1 month ago via VirtualRDC
  • New post: ANNOUNCEMENT: EMERGENCY DOWNTIME on ecco cluster July 21-22 2017
    about 1 month ago via VirtualRDC
  • Page edited: World Statistical Congress 2015 (ISI2015) session on "Synthetic establishment microdata around the
    about 3 months ago via VirtualRDC

Frequently asked questions (FAQ) on ECCO, VirtualRDC, SDS, and SSG

Print Friendly, PDF & Email

What is the distinction between SSG and SDS, and where IS the Social Science Gateway now?

The Social Science Gateway (SSG) grant has ended, please read here about ongoing availability of resources created as part of that project.

The Social Science Gateway (SSG) was a general purpose compute cluster, tied to the XSEDE, and focussed on providing assistance to social scientists in getting their research onto TeraGrid resources. It also provided compute resources to the core VirtualRDC constituency, i.e., users who are preparing data access request to the Census Bureau's Research Data Centers. The SSG is now closed, although VirtualRDC functionality continues to be provided through other means.

The Synthetic Data Server (SDS) is a custom compute server dedicated to providing structured access to early-access releases of innovative synthetic data. Data is provided by the Census Bureau, and the server is set up to closely replicate the structure of equivalent restricted-access compute servers housing confidential data within the U.S. Census Bureau. The SDS itself does not house any confidential data - all data has been vetted for release.

Where is the SIPP Synthetic Beta or the Synthetic LBD v2 on ECCO or the VirtualRDC?

In order to gain access to the SDS, you also get an account on ECCO or the VirtualRDC, but you cannot access the specific data that the SDS houses through those other compute resources. Please login to the SDS to access that data.

How do I request help?

  • For help with the ECCO, please email
  • For help with the SDS, please email Issues regarding the server itself (software, access), Cornell will address your issue. For issues with the data, your request will be forwarded to the relevant contacts at the Census Bureau (or you can email them directly).

How do I run SAS/Stata/R on ECCO?

In general, you need to either submit a request for an interactive job to the compute nodes (iqsub) or submit a longer-running job to the queue, using qsas, qstata, or a custom qsub job.

For interactive (GUI) SAS, you should simply be able to select "SAS" from the KDE or Gnome menu. For more details, see the Software section of the "Using.." page (for ECCO).

My qsub job got killed. What did I do wrong?

qsub debugging is not always easy. However, a couple of options allow you to dig down into the root cause. For one, use email notifications of job status to get more information. Add the following lines to your qsub script:

#PBS -m aeb
#PBS -M (your email address)

or add them to your qsub command line. The most common cause is that you did not request enough resources from the scheduler. Matlab and Stata no longer have mechanisms to restrict memory usage (both) and number of CPUs (Stata has a way to do that, Matlab does not), although SAS still gives you fine-grained access to this (see this  page). Your job needs to request appropriate CPU count, memory, and walltime resources - if any of those are exceeded while your job is running, your job will get killed. The following (command-line, or when prefaced by '#PBS', qsub script) options allow you to fine-tune your usage:

-l ncpus=N
-l mem=Nmb
-l walltime=HH:MM:SS

where N is an integer (so requesting 1GB of RAM means using '-l mem=1024mb'), and walltime is expressed in the obvious units (see qsub manpage for many other useful parameters).

Note that asking for the maximum amount (allowed by your queue) can work, but will delay the execution of your job until such resources become available (and in the future, may exhaust a CPU-hour quota faster). For maxima allowed by queues, please see this page.

Forgot password/account locked/my cat ate the paper with my password

Common causes of locked accounts, "failed authentication" responses in NX, and their solutions are:

  • Mistyping your password several times in a row.
    Solution: Wait about a 1/2 hour and then try again. Be sure that your caps lock key is not on!
  • Trying to login via NX  when you have a new or expired password (you get a "authentication failed" message even if you are sure that it is the right password).
    Solution: Login using SSH (see Step2). Passwords expire after a certain period. NX login facility does not have the ability to prompt you to change your password.
    Solution 2: Change your password at the CAC "My Account" page.
  • If all fails, request a password reset by from the appropriate email help address or using the  CAC "My Account" page, referencing your login ID. You will then also have to log in using SSH (see Step2).

My NX screen is black/blank/not working

(rare) If you can log in via SSH, but NX is still not working: Clean out the cache on the server side. Instructions here are for command line, but you can use a file system browser as well:

  • from SSH, type cd .nx (notice the dot in front of nx).
  • type ls. You should see a couple of directories that include the word "cache", and directory names that have a capital "C" at the start. You will delete them all (don't worry, they get recreated). Example: cache-gnome or
  • type rm -rf cache* C-ssg*

Now try to log in again with NX.

I want to use aliases on the command line, but the terminal ignores my alias file

For login shells, you want to put such commands into .profile. That may change in future versions. An example alias specification (for the bash shell) is

alias P="cd /rdcprojects/long/path/to/my/progs"

The second issue however is that you are launching the terminal from the GUI, and by default, it's not launched as login shell - and thus ignores the .profile. You can change that behavior.For Gnome (KDE is a bit different):

  • in an open terminal, open Edit | Current Profile...
  • go to the "Title and Command" tab
  • check the "Run command as a login shell" box

Now it should work.

Unsubscribing from listserv

You are automatically signed up to listservs notifying you of issues with the servers. Emails will be sent to the email address that you originally specified when signing up for access. If at any time you wish to unsubscribe from the listserv, follow instructions at