You are here: Home Experiment Information US ATLAS Getting Started Frequently Asked Questions

Frequently Asked Questions

by John S. De Stefano Jr. last modified Dec 20, 2016 04:52 PM

What hardware resources are available at the BNL regional center?

See our Getting Started page for a list of available US ATLAS hardware resources.

How do I request an account?

See User Accounts. If you have special needs or are dissatisfied with the way your new account has been set up, fill out a facility help request.

Once you have submitted an account request, it will be verified before being created. You will be informed once your account has been created. This may take up to 24 hours depending on the time of day and other requests that are being processed.

How do I use email at the facility?

See Email Services.

Can I get a simpler email address?

Yes. Email users can register for LabMail services, which are provided by ITD. Users are strongly encouraged to use their LabMail email addresses in preference to their direct atlas00 addresses.

How do I interactively connect to the regional center from my remote site?

The regional center is protected by a firewall. All interactive connections must pass through the firewall via SSH. There is a gateway machine that allows you to effectively bypass the firewall.

From any external site, you can establish an ssh connection to From this machine, you can then make an ssh connection to any of the Linux farm nodes or atlas00. The sole purpose of this node is to be an SSH "pass-through". No other services are available. This allows the machine to have a network interface outside the firewall without causing too much trouble with laboratory security. This host has a second network interface INSIDE the firewall, so your SSH connection does not even see the firewall. Any work on the firewall has no effect on SSH sessions.

It is also possible to establish a direct SSH connection to atlas00. This node is inside the firewall, so the connection does pass through the firewall. When the firewall needs to be reset, such connections are lost. Users are strongly discouraged from using atlas00 solely to establish ssh connections to the Linux farm. Not only are these connections subject to firewall resets, but they also increase the number of open sessions on atlas00 unnecessarily.

How do I set my path?

The path should be set for you when you get an account. However, you should check your path to ensure that it is correct. Here is an example of what your path should look like:

set path=(                                 \
          .                                \
          ~                                \
          /opt/usatlas/bin                 \
          /bin                             \
          /usr/local/bin                   \
          /usr/bin                         \
          /usr/sbin                        \
          /usr/local/lib                   \
          /usr/lib                         \
          /opt/SUNWspro/bin                \
          /usr/ucb                         \
          /etc                             \
          /usr/etc                         \
          /usr/X/bin                       \
          /usr/local/man                   \
          /usr/man                         \
          /usr/local/lib/X11/app-defaults  \
          /usr/afsws/bin                   \
          /usr/afsws/etc                   \
          /usr/openwin/lib                 \
          /usr/openwin/lib/config          \
          /usr/openwin/share/include/X11   \
          /usr/openwin/include             \
          /usr/openwin/bin                 \
          /usr/ccs/bin                     \
          /cern/pro/bin                    \
          /cern/pro/lib                    \
          /afs/   \

Note that /usr/local/bin and /usr/local/lib appears before /usr/bin and /usr/lib respectively. This ensures that you are getting the most up-to-date, maintained version of binaries and libraries from ASIS at BNL. Note also software tools not available through ASIS or other places or software tools are maintained in /opt/usatlas/bin. Software products that are not correct in /usr/local/bin are reinstalled in /opt/usatlas/bin. Hence /opt/usatlas/bin should appear first in your path.

Other things in your path of interest are:

  • /afs/ which you need if you are using ATLAS software at BNL.
  • /cern/pro if you need CERN libraries.

How do I report problems?

Fill out a Problem Reporting ticket to report any problems with the facility. There are various categories that have been established. Pick the category that best suites the nature of your problem. If you are not sure of the category, you may select the 'general' category. The ticket will then be sent to the person responsible for the problem who will fix the problem and send you a notification or who will contact you for further information.

Can I get a personal web space area?

Yes. See US ATLAS User Web Pages.

How do I access the US ATLAS TWiki?

Separate TWiki accounts are not required. See US ATLAS TWiki Publishing and Security Details.

How will I know if there is any system work that is going on which may effect my ability to work at the regional center?

When you get an account, you will automatically be subscribed to the usatlas-users mailing list. Notification of system upgrades, down-times, and other facility related information will be posted to the list in advance whenever possible. In addition to email notification, such information is visible on our home page and listed on our announcements page.

Document Actions