Please consider increasing the common.h:MAX_ID_LEN value. Length of 21 is not enough for some custom mount points. (libs/zbxsysinfo/linux/diskspace.c:fsname).

The discovery of such mount points works fine. The error is seen when agent tries to find the path.

zabbix_get -k vfs.fs.size[/u03/app11/PROD/db/bcprj,free]
ZBX_NOTSUPPORTED: Cannot obtain filesystem information: [2] No such file or directory