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Environment

Introduction to the PDC environment. Learn more about security, storage and more.

Support

As a user you should look for and read the information available on this web to get acquainted to the PDC environment and to learn how to resolve the most common problems. You are of course always welcome to contact us at PDC.

Changing password

The password is changed by the command kpasswd (not passwd!), see this page for more details. You need to load the module heimdal to get kpasswd in your path.

Handling Email

You need to get your PDC e-mail forwarded to your favourite home site, please find the instruction here describing the proper procedure. PDC will occasionally send mail to its users using their e-mail address at PDC. It is therefore crucial that you either take care of forwarding your mail from PDC to a location where you regularly read your mail.

Mailing lists and System alerts

In order to get information about upcoming events, courses we recommend that users sign up for the PDC announce mailing list. Urgent system information and planned system updates are posted on this mailing list, which most users definitely should subscribe to.

Modules

At PDC there is a variety of machines, operating systems, projects, different versions of the same code that all have their special set of programs to run. To be able to maintain and use this large set of programs we supply you with the concept of modules, invoked by the `module' command.

Storage

PDC users have their home directories in the distributed filesystem AFS. For production jobs a site wide high-performance filesystem is used. More information about AFS and our parallel storage solutions can be found here.

Kerberos

We use Kerberos for local and remote authentication. One of the unpleasant realities of today is that computer networks are to be considered unsafe, and therefore it is important that secrets like passwords never are sent in clear text across the network. Usually the password is sent like that when you log in remotely or when you transfer files. It is therefore important to note that the high security must begin at the local machine, and this is why we use Kerberos software , that should be installed in your local machine prior to logging in to PDC.

In the PDC environment, we have replaced ssh, scp, rsh, rlogin, rcp with kerberized equivalents that do not use your password to authenticate to the remote system. Instead they use a so-called ticket. This ticket is acquired in a secure way on the local machine (usually via one of the commands kinit or kauth) before a connection to the remote system is opened.

To prevent replay attacks authentication expires over time. You will have to prove your identity at regular intervals (usually once a day). This is usually only a problem for batch jobs that sit in a queue for a long time, and for that particular problem there are special measures available.

You should read more about our security here.