@Ilia I just disabled info collecting after one instance started. Now only one instance of collectinfo.pl is running and local disk space usage statistic is dropping 10 MB by every 3 seconds (more or less).
I have had disabled info collecting for 3-4 months so maybe it’s clearing some things up but exactly I don’t know what.
This is our one of the prod. server so I can’t install extra packages but here’s the specs:
CPU: Xeon E3-1275 v6
Ram: 64 GB
Disk: 512 GB NVMe SSD (%35 used)
OS: Debian 10 (Buster)
Webmin: 1.962
Virtualmin: 6.14
Installation: Virtualmin Minimal
Extra packages: ProFtpd, Awstats, PHP 7.x versions with FPM (apache)