Each HPC system has a large disk mounted on /nobackup for temporary storage of input/output files for jobs. Data is not backed up and will be periodically cleared to ensure enough capacity is available to running programs.

/nobackup is constructed using the Lustre parallel filesystem. ARC3 has ~836TB at 4GB/s and ARC2 has ~170TB at 5GB/s.

Although highly resilient internally, users should not rely upon this resilience for data protection and important data should be moved off this filesystem, to a different location, once compute jobs/IO is complete.

To ensure sufficient space and bandwidth is available to the system’s workload, the /nobackup disk will be purged periodically.

Users should not rely upon the /nobackup disk for their long-term data storage needs.


To access the /nobackup filesystem from the command prompt:

% cd /nobackup

When using for the first time, you are encouraged to make a directory under /nobackup to store your data e.g.:

% mkdir /nobackup/username
% cd /nobackup/username

Data can then be copied into that area using cp (or scp from remote):

% cp -r ${HOME}/data /nobackup/username/

Note about small file sizes

/nobackup is optimised for large files (where large is >1Mb). File access to lots of small files will not obtain the best out of the filesystem and will slow down your applications.