OpenBSD is an intelligent, smart OS but unfortunately the same does not apply to all software out there which you can install on your computer. I recently found out thanks to the script that I post in this page that there was a mysterious .cache in my /home taking as much as about 30G.
The following script should work for any UNIX-like OS, but I am not sure. It is fast and allows you to find out where the potential memory eater is.
#!/bin/sh
echo""
echo "Non-hidden files and directories"
echo "--------------------------------"
du -sk ./* | sort -n | awk 'BEGIN\
{ pref[1]="K"; pref[2]="M"; pref[3]="G";} \
{ total = total + $1; x = $1; y = 1; while( x > 1024 )\
{ x = (x + 1023)/1024; y++; } printf("%g%s\t%s\n",int(x*10)/10,pref[y],$2); }\
END\
{ y = 1; while( total > 1024 ) { total = (total + 1023)/1024; y++; }\
printf("Total: %g%s\n",int(total*10)/10,pref[y]); }'
echo""
echo "Hidden files and directories"
echo "----------------------------"
du -sk ./.* | sort -n | awk 'BEGIN\
{ pref[1]="K"; pref[2]="M"; pref[3]="G";} \
{ total = total + $1; x = $1; y = 1; while( x > 1024 )\
{ x = (x + 1023)/1024; y++; } printf("%g%s\t%s\n",int(x*10)/10,pref[y],$2); }\
END\
{ y = 1; while( total > 1024 ) { total = (total + 1023)/1024; y++; }\
printf("Total: %g%s\n",int(total*10)/10,pref[y]); }'