New mek-quake

New mek-quake

This is a large cluster system to be used by the Wales and Vendruscolo groups. There are some decisions to be made about setting it up.

On clust (the other Wales group cluster) there are dual-CPU nodes but these are deliberately hidden from the queueing system. The smallest unit you can get is a single node. This was to avoid the situation we get on nimbus, a similar machine, where parallel jobs sometimes get assigned one task on certain nodes, instead of two. This seems to happen despite the queues being configured to ask for two tasks per node on parallel jobs but it is always possible for users to reset this so I do not know if it is a Maui bug or user error.

The clearly will not scale to 4-way nodes on the new machine, so

we shall have to allow mixed jobs on nodes. Not sure how to avoid

the users resetting the tasks per node though. A qsub wrapper would be complex as it would also have to process the job script.

Assuming we do not need variable fairshare for different groups it could be done with QOS but this is a bit of a bodge

Are we going to need variable fairshare?