Following error in mod_security error log:

/var/lib/mod_security/default_SESSION": No space left on device

We are using DETECTION_ONLY.

ls -lh /var/lib/mod_security
total 11M
-rw-r----- 1 daemon daemon 8.6M Mar 12 02:13 default_SESSION.dir
-rw-r----- 1 daemon daemon 118G Mar 12 03:24 default_SESSION.pag
The folder size is 11M showing but the file inside this is showing 118G.

What may be the reason? Since it already writing to log, what is the purpose of default_SESSION file? Can we prevent write to this file?