The dCache statistics module collects information on the amount of data stored on all pools and the total data flow including streams from and to tertiary storage systems. The module produces an ASCII file once per hour, containing a table with information on the amount of used disk space and the data transferred starting midnight up the this point in time. Data is sorted per pool and storage class. In addition to the hourly statistics, files are produced reporting on the daily, monthly and yearly dCache activities. If enabled, a ’html’ tree is produced and updated once per hour allowing to navigate through the collected statistics information.

The dCache statistics module will be part of dCache releases 1.6.7 and higher. The code is part of 1.6.6 but needs to be enabled. At the end of this chapter some advise is given on how to do that.