说明：
cacti跑了一段时间，突然发现cacti图像都是nan，但snmpwalk -c public -v 2c 127.0.0.1 system数据是有的，这说明snmp是运行正常的。新建graph时./cacti/rra/下面没有生成.rrd文件。rra目录及目录下文件权限已经改为777，还是一样。在Graph Management开启debug模式说.rrd’: No such file or directory，手动执行/usr/local/php/bin/php /home/www/data/cacti/poller.php提示error while loading shared libraries: libmysqlclient.so.15: cannot open shared object file: No such file or directory。
排查：
1.因为snmpwalk有拿到数据，说明snmp没有问题。
# snmpwalk -c public -v 2c 127.0.0.1 system //有数据，说明没问题
2.新建个graph，分别在Graph Management，Data Source开启debug模式测试
Console ｜ Graph Management |Turn On Graph Debug Mode RRDTool Says: ERROR: opening '/home/www/data/cacti/rra/localhost_hdd_free_70.rrd': No such file or directory Console | Data Source | Turn On Data Source Debug Mode Data Source Debug /usr/local/bin/rrdtool create /home/www/data/cacti/rra/localhost_load_1min_80.rrd --step 300 DS:load_1min:GAUGE:600:0:500 DS:load_5min:GAUGE:600:0:500 DS:load_15min:GAUGE:600:0:500 RRA:AVERAGE:0.5:1:500 RRA:AVERAGE:0.5:1:600 RRA:AVERAGE:0.5:6:700 RRA:AVERAGE:0.5:24:775 RRA:AVERAGE:0.5:288:797 RRA:MAX:0.5:1:500 RRA:MAX:0.5:1:600 RRA:MAX:0.5:6:700 RRA:MAX:0.5:24:775 RRA:MAX:0.5:288:797
3.怀疑是spine的mysql密码更改
# /usr/local/mysql/bin/mysql -ucacti -p //能登陆说明用户，密码正确 # vim /usr/local/cacti-spine/etc/spine.conf //用户，密码也正确
4.手动执行/usr/local/php/bin/php /home/www/data/cacti/poller.php
# /usr/local/php/bin/php /home/www/data/cacti/poller.php //提示
error while loading shared libraries: libmysqlclient.so.15: cannot open shared object file: No such file or directory
# ldd /usr/local/cacti-spine/bin/spine //可以看到libmysqlclient_r.so.15 => not found
linux-vdso.so.1 => (0x00007fff29be6000)
libnetsnmp.so.25 => /usr/local/net-snmp/lib/libnetsnmp.so.25 (0x00002b252025d000)
libmysqlclient_r.so.15 => not found
libcrypto.so.6 => /lib64/libcrypto.so.6 (0x0000003956800000)
libz.so.1 => /lib64/libz.so.1 (0x0000003369600000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003369e00000)
libm.so.6 => /lib64/libm.so.6 (0x0000003369200000)
libc.so.6 => /lib64/libc.so.6 (0x0000003368e00000)
libdl.so.2 => /lib64/libdl.so.2 (0x0000003369a00000)
/lib64/ld-linux-x86-64.so.2 (0x0000003368a00000)
5.才想起原来系统有2个mysql，一个自己编译mysql 5.1.38，一个是系统自带(版本更低)。当初编译安装spine时，–prefix=/usr/local/cacti-spine –with-snmp=/usr/local/net-snmp/没有指定mysql。spine编译时使用原系统自带的mysql的libraries库。而后来我把系统自带的mysql删掉。导致snmp能拿到数据，spine却没有办法写入mysql库，rrd没办法拿到数据绘图，/cacti/rra/目录下当然就没有文件。。
解决：
重新编译spine
# wget http://www.cacti.net/downloads/spine/cacti-spine-0.8.8a.tar.gz # tar zxvf cacti-spine-0.8.8a.tar.gz # cd cacti-spine-0.8.8a # ./configure --prefix=/usr/local/cacti-spine --with-snmp=/usr/local/net-snmp/ # make && make install
# ldd /usr/local/cacti-spine/bin/spine //可以看到libmysqlclient_r.so.16 => /usr/local/....
linux-vdso.so.1 => (0x00007fffdf5fd000)
libnetsnmp.so.25 => /usr/local/net-snmp/lib/libnetsnmp.so.25 (0x00002ab1399f5000)
libmysqlclient_r.so.16 => /usr/local/mysql/lib/mysql/libmysqlclient_r.so.16 (0x00002ab139cca000)
libcrypt.so.1 => /lib64/libcrypt.so.1 (0x000000337b400000)
libnsl.so.1 => /lib64/libnsl.so.1 (0x0000003371400000)
libcrypto.so.6 => /lib64/libcrypto.so.6 (0x0000003956800000)
libz.so.1 => /lib64/libz.so.1 (0x0000003369600000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x0000003369e00000)
libm.so.6 => /lib64/libm.so.6 (0x0000003369200000)
libc.so.6 => /lib64/libc.so.6 (0x0000003368e00000)
libdl.so.2 => /lib64/libdl.so.2 (0x0000003369a00000)
/lib64/ld-linux-x86-64.so.2 (0x0000003368a00000)
等一下就可以看到cacti又有数据了。