Churn is used to churn a number of files by a % changerate.
./churn -v 10% /path/to/files
This will create files adding 10% total space to the file path.
./churn -d -v 20% /path/to/files
This will change 20% of the total size of data, by deleting files and creating newer ones, to simulate daily data change rates.
You will need to set 3 options in the churn script before running it:
MIN_SIZE - Minimum filesize to be created MAX_SIZE - Maximum filesize to be created MAX_FILES_PER_DIRECTORY - Maximum files per data directory
Churn requires 'dd' to be in your path as well as access to /dev/urandom