Note: This is not the canonical documentation, but is available here for reference.
Reference the official Unity docs here.

Below is a table of all available storage on Unity.

MountpointNameLocationTypeQuotaDescription
/homeHome directoriesEverywhereHDD10 GBHome directories should be used only for user init files.
/workWork PI directoriesEverywhereSSD3 TBWork should be used as the primary location for running cluster jobs. This is a shared folder for all users in the PI group. 
/projectProject directoriesEverywhereHDDVaryingProject directories are created on request. Good for large dataset storage or any larger storage that is not directly used for job I/O. Email hpc@umass.edu to request. A common use case is generating job output in /work and copying to permanent storage in /project afterwards. Not for job I/O
/scratch/workspaceScratch Workspace spaceEverywhere (Intended for Compute)SSDUp to 50 TBSpace meant for a time-limited window that spans across jobs. See HPC Workspace documentation for more information.