From the automatic purge of unused files in SCRATCH is enforced. Any files that have not been accessed at any time in the previous 30 days will be automatically deleted. This purge will be conducted regularly, in order to keep the usage of this filesystem within optimal parameters.
SCRATCH is designed to hold temporary large files and to act as the main storage and working filesystem for your jobs and experiments input and output files, but not to keep data for long term.
We strongly encourage you to regularly review your SCRATCH usage and move any data you wish to keep to other locations such as HPCPERM, PERM or ECFS.
See HPC2020: Filesystems and ECFS user documentation for more information on the storage offering at ECMWF.