We upgraded the PRTG to the version 9.1 and we are trying to add a SNMP sensor for the disk of a Unix machine to monitor the free space but we need to monitor the disk remaining. If less than 80% of the disk is used we need to send an alert. What I found today is a "SNMP Linux Disk Free" sensor that monitor the space on the phisical partitions and not on the logical partitions (/, /tmp, /var etc). I found using "SNMP Library" Paessler common that is possible to see the store used and storage size of the partitions but when I monitor this in % I can only see that the store is 0% (that is the total storage size) and the disk used is 0% (total disk used) and we need a sensor that verifies the total disk and monitor the used space and shows in %. I know that in previous versions we had this option. How can we achieve this goal using this new version?