DAS-3 Usage Policy
Each DAS-3 cluster consists of a headnode (file/compile server) and a number of compute
nodes. The headnode is called fsX (X is 0, 1, 2,
3 or 4 according to the cluster base); the worker nodes are named nodeX[0-9][0-9].
The DAS-3 must be used in the following way:
Program development (editing, compiling) is done on the headnodes, i.e., the file/compile servers.
Program execution MUST be done on the compute nodes, NEVER on a
headnode. The headnodes are usually heavily loaded just carrying
out the tasks they are intended for. User programs that run on a headnode
harm all other users of that DAS-3 cluster! This rule also holds for sequential
runs of parallel programs.
Running of jobs on the worker nodes MUST be done via the DAS-3 cluster scheduling
system Sun Grid Engine (SGE), which offers
sufficient abstraction and flexibility for nearly all needs.
A full documentation set is available.
The user interface of the original DAS scheduler
prun has also been ported to the DAS-3
scheduler. For many users this will be the most convenient way to start jobs on one of the
The default run time for jobs scheduled on DAS-3 is 15 minutes, which is also the maximum
during working hours, from 08:00 to 20:00. We do not want people to monopolize the clusters for a
longer time, since that makes interactively running short jobs on a large number of nodes practically
impossible. Also, to get a reasonable spread of the load on DAS-3, preferably use the cluster at your
own site, unless it is overloaded and another one happens to be free.
DAS-3 is specifically NOT a cluster for doing production work. It is meant for people doing
experimental research on parallel and distributed programming. Only during the night and in the weekend,
when DAS-3 is regularly idle, it is allowed to run long jobs. In all other cases, you will first have
to ask permission in advance from firstname.lastname@example.org to make sure you are not causing too much trouble
for other users.
NOTE: Users who do not obey these usage rules, risk blocking of their account!
DAS-3 User Accounts and DAS-3 Job Execution.