TSUBAME 3.0 provides the following scratch area.
For details, please refer to Storage use on Compute Nodes in the TSUBAME3.0 User's Guide 

1. Local scratch area
The environment variable $TMPDIR that is allocated only on compute node is the local scratch area.

$ TMPDIR is usually a unique directory for each job under /scr.

You can not write directly under /scr.
 

2. Shared scratch area
It is available only for the batch job script using f_node of resource type F. Please specify "#$ -v USE_BEEOND=1".
/beeond directory is allocated.

3. /tmp directory
There is a 2GB capacity limit for the /tmp directory.
There is a concern that problems such as hanging up of the execution program may occur when creating large scratch files.
Please consider using the scratch directories in 1. and 2.