By default Redstor Online Backup Plus creates logs within the following locations. Please note that the location is operating system specific. See Log Locations
Relocating the Logs
Within the config.ini file found with C:\Program Files\Redstor Online Backup Plus\ add the following lines to the file where "D:\Example" is the location you wish to relocate the logs to.
Having done this restart the "Redstor Online Backup Plus Service Controller".
NOTE: This feature is supported from 14.2.1 upwards.