While working on a case, PAM Support may be asking for a change in the SPFD log level on the Configuration > Diagnostics > Diagnostic Logs page. Options Info+WolfSSL and Debug+WolfSSL include additional logging from the WolfSSL libraries. While either of these options is enabled, there is a continuous increase in disk usage. On a busy system this can be rather rapid and the disk may fill up in a few days.
Affects PAM releases up to 4.2.0.
The WolfSSL module logs into a separate log file, which is not subject to daily log rotation in releases up to 4.2.0.
This problem is fixed in 4.2.1 and later releases, where the log file is added to the list of files rotated daily, see the following item on documentation page Resolved Vulnerabilities and Issues in 4.2.1:
36054293 DE624798 Increased disk usage with WolfSSL logging enabled.
In general, these log levels are meant to be set only while reproducing a problem with PAM Support. The SPFD log level always should be set back to "Info" afterwards, in which case the WolfSSL log file stops growing.