UC Santa Cruz

We compare and contract long-term file system activity for different Unix environments for periods of 120 to 280 days. Our focus is on finding common long-term activity trends and reference patterns. Our analysis shows that 90% of all files are not used after initial creation, those that are used are normally short-lived, and that if a file is not used in some manner the day after it is created, it will probably never be used. Additionally, we find approximately 1% of all files are used daily. This information allows us to more accurately predict the files which are never used. These files can be compressed or moved to tertiary storage enabling either more users per disk or larger user disk quotas.