On many UNIX platforms a tmpfs can be used for storing data in volatile memory that behaves like an ordinary mount point in the file system (http://en.wikipedia.org/wiki/Tmpfs).

In cases, where jobs are doing a lot of i/o operations on certain files, transfering files into the tmpfs can have advantages:

1. Faster file access.
2. Reduction of file server load.
3. Speed up of calculations.

However, space used by files in the tmpfs is no longer available for user processes. So for memory intensive jobs, scratch data might be stored elsewhere.

On VSC-2 the compute nodes have a tmpfs mounted on /tmp. Currently /tmp is set to default size which is 50% of the available memory of the nodes, i.e. 16 GB. For using /tmp a sample job would be:

#$ -N test

cd <INPUT_DIR>
cp -r * /tmp
cd /tmp

./a.out

cp -r * <OUT_DIR>