Graphs not showing on cacti 0.8.8b on centos

[phanimedisetty]

hi
any one can give me solution i have installed cacti 0.8.8b in centos graphs are not displaying

RRDTool Command:

/usr/bin/rrdtool graph - \
--imgformat=PNG \
--start=-86400 \
--end=-300 \
--title='mydevice - mydevice Disk Usage' \
--rigid \
--base=1024 \
--height=120 \
--width=500 \
--alt-autoscale-max \
--lower-limit='0' \
--vertical-label='Megabytes' \
--slope-mode \
--font TITLE:10: \
--font AXIS:7: \
--font LEGEND:8: \
--font UNIT:7: \
DEF:a='/var/www/html/cacti-0.8.8b/rra/2/137.rrd':'fg_SysDiskCapacity':AVERAGE \
DEF:b='/var/www/html/cacti-0.8.8b/rra/2/138.rrd':'fg_SysDiskUsage':AVERAGE \
DEF:c='/var/www/html/cacti-0.8.8b/rra/2/136.rrd':'fg_SysCpuUsage':AVERAGE \
AREA:a#00E800CC:'Disk Capacity' \
GPRINTLAST:'Current\:%8.2lf %s' \
GPRINTAVERAGE:'Average\:%8.2lf %s' \
GPRINTMAX:'Maximum\:%8.2lf %s\n' \
LINE2:b#000000FF:'Disk Usage' \
GPRINTLAST:' Current\:%8.2lf %s' \
GPRINTAVERAGE:'Average\:%8.2lf %s' \
GPRINTMAX:'Maximum\:%8.2lf %s\n' \
COMMENT:'\n' \
COMMENT:'Total hard disk capacity and Current hard disk usage (MB)\n' \
COMMENT:'Last Poll\: Thu 01 Jan 05\:30\:00 IST 1970\n'

RRDTool Says:

ERROR: opening '/var/www/html/cacti-0.8.8b/rra/2/137.rrd': No such file or directory

[cigamit]

http://docs.cacti.net/manual:087:4_help ... #debugging