Filesystems
Once logged in, users will by default be placed in the /home/username directory. This filesystem is provided by Sun X4500 storage devices, and is recommended for storing files which are likely to be needed longer term, e.g source data and programs. This is the only part of the HPC user filesystem which is backed up, as it is mirrored to another server. Currently, there is no archiving facility on the HPC system, so files which are deleted by the user cannot be recovered.
Once users have been given access to the cluster, in response to their application to hpc@nottingham.ac.uk they will be allocated a work area under /work/workN/username (where N is a number). This work area is accessible by the compute nodes, and should be used for all files that are required by a users job, and jobs should be submitted from here. The storage for the work area is provided by a Panasas parallel storage appliance, delivering approximately 91 Terabytes of space, split between the various work areas. The work area should be considered a temporary storage space, as it is not backed up, although the filesystem does have some internal redundancy via a RAID scheme.
Some applications may need to use storage from the local disk on the compute node, accessible via /tmp or /scratch.