You are using Collectd 4, which is deprecated by CGP. Graphs like df and interfaces may be incomplete.
humpty-frei-saigon

uptime

"-l" "0" "-w" "800" "-h" "350" "-t" "Uptime on humpty-frei-saigon" "-v" "Days" "-s" "e-8035200" "DEF:avg_1d775834=rrd.php?path=humpty-frei-saigon%2Fuptime%2Fuptime.rrd:value:AVERAGE" "DEF:max_1d775834=rrd.php?path=humpty-frei-saigon%2Fuptime%2Fuptime.rrd:value:MAX" "CDEF:c_avg_1d775834=avg_1d775834,86400,/" "CDEF:c_max_1d775834=max_1d775834,86400,/" "VDEF:v_avg_1d775834=c_avg_1d775834,AVERAGE" "VDEF:v_max_1d775834=c_max_1d775834,MAXIMUM" "CDEF:area_1d775834=c_avg_1d775834" "AREA:area_1d775834#bff7bf" "LINE1:area_1d775834#00e000:Current" "GPRINT:c_avg_1d775834:LAST:%.1lf days\l" "LINE1:v_max_1d775834#FF0000:Maximum:dashes" "GPRINT:v_max_1d775834:%.1lf days\l" "LINE1:v_avg_1d775834#0000FF:Average:dashes" "GPRINT:v_avg_1d775834:%.1lf days\l"