OPNsense Forum

English Forums => General Discussion => Topic started by: droumanet on January 16, 2026, 07:16:14 PM

Title: Memory leak or not?
Post by: droumanet on January 16, 2026, 07:16:14 PM
Hi there,

I manage my firewall with Zabbix since few days, because having lot of trouble (many crashes) on my OPNsense firewall. Well, after two days, it seems there is a memory leak, but maybe, the firewall will update it processes and release all the memory?
Are some of you able to share same graph to see the health of our firewalls? Datas are coming from Zabbix agent.
(https://image2url.com/r2/default/images/1768587202982-f27ba9c2-4470-440c-85ef-2672e3581a98.png)
Title: Re: Memory leak or not?
Post by: nero355 on January 16, 2026, 07:22:43 PM
Check if your issue is related to this : https://forum.opnsense.org/index.php?topic=49552.msg256645#msg256645

TL;DR : DNSmasqd crashing because of a possible memory leak...
Title: Re: Memory leak or not?
Post by: droumanet on January 18, 2026, 01:02:59 AM
I've not enabled this service, only Unbound DNS.
But I'll have a look to a way to monitor precisely processes RAM consumption.
Title: Re: Memory leak or not?
Post by: droumanet on January 27, 2026, 10:36:10 PM
I think it's not a memory leak, but the way FreeBSD manage memory (to avoid disk caching).
Solved (I hope... a crash with lagg0 has reset my statistics)
(https://image2url.com/r2/default/images/1769549680548-a59a9118-e419-4f32-967c-6986e95b0631.png)
Title: Re: Memory leak or not?
Post by: pfry on January 28, 2026, 04:17:53 AM
I hadn't thought of differences in utilities - how does it look in top, for instance?

[...]
Mem: 101M Active, 363M Inact, 2732M Wired, 104K Buf, 27G Free
ARC: 1357M Total, 767M MFU, 407M MRU, 9081K Anon, 23M Header, 149M Other
    1047M Compressed, 3182M Uncompressed, 3.04:1 Ratio
[...]

The ARC allocation (generally) grows from boot to a stable level. Some memory utilization reports neglect/subtract ARC (e.g. the percentage reported in the dashboard widget), so memory usage may appear more stable. So yes, a characteristic of FreeBSD (with ZFS, at least).