Can not find it where? The gui log is only going to show the last X number of entries.. No matter how big you make the file..
Also when you adjusted your log size from the default 500 did you read the NOTE.. Where you have to clear for the new size to take effect..
NOTE: Log sizes are changed the next time a log file is cleared or deleted. To immediately increase the size of the log files, first save the options to set the size, then clear all logs using the "Reset Log Files" option farther down this page.
Setting log files to 10G would be ALL log files, not just the filter.log so you could run out of space setting them too big..
Here I just modified mine to be 5MB in size each… After reset you can see in the dir they are all set to 5MB
[2.4.2-RELEASE][root@sg4860.local.lan]/var/log: ls -lah
total 88816
drwxr-xr-x 6 root wheel 1.0K Feb 7 14:00 .
drwxr-xr-x 29 root wheel 512B Jan 23 21:52 ..
-rw-r–r-- 1 root wheel 42K Sep 17 20:05 bsdinstall_log
-rw------- 1 root wheel 4.8M Feb 16 13:30 dhcpd.log
-rw-r–r-- 1 root wheel 9.7K Jan 11 14:45 dmesg.boot
-rw------- 1 root wheel 4.8M Feb 16 13:31 filter.log
-rw–----- 1 root wheel 4.8M Feb 16 13:29 gateways.log
-rw-r–r-- 1 root wheel 10K Jan 23 13:06 haproxy.log
-rw------- 1 root wheel 4.8M Feb 16 13:29 ipsec.log
-rw–----- 1 root wheel 4.8M Feb 16 13:29 l2tps.log
<snipped>In your system log settings what does it show you for space of your log files… Here is mine after I adjusted to 5MB size
Disk space currently used by log files is: 94M Remaining disk space for log files: 20G</snipped>