With IPHost Network Monitor you can run simple snmp requests against a IBM device in your network.
thinserverHardFileSpace
thinserver Hard File Space
1.3.6.1.4.1.2.6.119.2.3.1.6
This is the total amount of hard file space, in kilobytes, which can be used for the files being cached for the thin server function.
Back to ibm-tsvrmib MIB page.
IPHost Network monitor allows you to monitor thinserverHardFileSpace on IBM device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring IBM computers right now.