Interactive use of the PPPL cluster
There are two types of interactive use on the cluster, non-exclusive
and exclusive.
For non-exclusive use, ssh to portal.pppl.gov. This is an alias
for several systems where logins are allocated to the systems in a
least loaded fashion. You use portal
as you would any timesharing system, and you will be one of many users
on the system. So it is important to not run very high CPU or memory
intensive processes on portal. Instead, reserve a set of
systems for your exclusive use as detailed in the next section.
(The portal set of systems runs a 64 bit kernel. You can run 32
or 64 bit executables on this kernel).
For exclusive use of a system
or systems, ssh to portal and execute the command use.
This command will ask you a few questions about the number and
types of hosts you wish to use, then allocates those hosts for your
exclusive use from a pool of systems reserved for this type of use. No
other users will be allowed onto those hosts. This provides you with
uninterrupted and non-contentious use of the hosts.
By default, the use command
allocates the system to you for 16 hours. To override this, type use -w hh:mm, for example use -w 24:00 to use the system
exclusively for 24 hours.
Your exclusive interactive request is queued and scheduled just like
any other job, but when executed, the standard input, output, and error
streams of the job are connected through your terminal session.