Secure Shell Login and File Transfer

To be able to access HPC2N clusters from a remote computer using your login name and password, you need to use a secure shell (optionally with GSSAPI). On UNIX / Linux platform we recommend using ssh (secure shell) for login and scp  (secure copy) for file transfer. The following table shows recommended clients for all major platforms:

Documentation can be found on the above sites or by typing man ssh or man scp in a UNIX / Linux terminal. There is also a page here with more information about SSH X11 forwarding. The following example shows connecting to Akka from your localhost and copying a file (found in your home directory) from Akka to the /tmp directory on your localhost: 

localhost> ssh yourusername@akka.hpc2n.umu.se
localhost> scp yourusername@akka.hpc2n.umu.se:file /tmp

(Note: If you have logged in to HPC2N for the first time you must change your password; see below  First Time Login / Password Change.)

Login with GSSAPI (Generic Security Services Application Program Interface)

HPC2N systems can also be accessed through GSSAPI-aware clients.  GSSAPI allows you to type your password once when obtaining your Kerberos ticket, and while that ticket is valid you don't have to retype your password.

GSSAPI with ssh and PuTTY clients

For the ssh client, enable the following configuration options in $HOME/.ssh/config:

Host *.hpc2n.umu.se
 GSSAPIAuthentication       yes
 GSSAPIDelegateCredentials  yes
 PreferredAuthentications   gssapi-keyx,gssapi-with-mic,password

Note that the Host keyword restricts the subsequent declarations to a specific host or domain (HPC2N). Also note that for the above options to work, the ssh client had to be previously compiled with the configuration option --with-kerberos5.

Before running the ssh command make sure you have a valid Kerberos ticket (klist command) or obtain one by running the kinit command.

$ kinit <username>@HPC2N.UMU.SE

On Windows users can use PuTTY-aware GSSAPI client. Versions 0.60, 0.59 and 0.58 are available from these locations: matthew.loar.name/software/putty/, putty-0.59-with-gssapi.zip, PuTTY-0.58-GSSAPI-2005-07-24.zip. In PuTTY configuration menu Connection–>Auth make sure that both of the Kerberos 5 GSSAPI boxes are checked.

First Time Login / Password Change

The first time you log in to any HPC2N system (see the section above on how to log in using ssh) you must change your password. This is done using the passwd command:

p-bc9901 [~]$ passwd

A good way to remember passwords is to use a mnemonic, like a phrase or a word that will help you remember it, and means something for you, but not to others.

The road E4 pass through Umeå! = TrE4ptU!