look at:
http://support.nagios.com/forum/viewtop ... 16&t=7930
here i asked how to delete old performance data. So i did.
[root@localhost ~]# ll /usr/local/nagios/var
total 39137596
drwxrwxr-x 2 nagios nagios 16384 Nov 5 00:00 archives
-rw-r--r-- 1 nagios nagios 131796 Mar 7 2012 graphapi.log
-rw-rw-r-- 1 nagios nagios 5554770587 Nov 5 19:37 host-perfdata
-rw-r--r-- 1 nagios nagios 5 Nov 4 10:59 nagios.lock
-rw-r--r-- 1 nagios nagios 375891 Nov 5 19:35 nagios.log
-rw-r--r-- 1 nagios nagios 5 Nov 3 19:23 ndo2db.lock
-rw-rw-r-- 1 nagios nagios 0 Nov 4 10:59 ndomod.tmp
srwxr-xr-x 1 nagios nagios 0 Nov 3 19:23 ndo.sock
-rw-r--r-- 1 nagios nagios 11259 Nov 5 15:58 npcd.log
-rw-r--r-- 1 nagios nagios 10485834 Nov 2 12:43 npcd.log.old
-rw-r--r-- 1 nagios nagios 2134680 Nov 4 10:59 objects.cache
-rw-rw-rw- 1 nagios nagios 4291185 Jul 27 12:22 perfdata.log
-rw------- 1 nagios users 3293364 Nov 5 18:59 retention.dat
drwxrwsr-x 2 nagios nagcmd 4096 Nov 4 10:59 rw
-rw-rw-r-- 1 nagios nagios 34498029786 Nov 5 19:37 service-perfdata
drwxr-xr-x 5 nagios nagios 4096 Feb 1 2012 spool
drwxr-xr-x 2 nagios nagios 4096 Aug 7 14:01 stats
-rw-rw-r-- 1 nagios users 3276903 Nov 5 19:37 status.dat
tail -f /usr/local/nagios/var/perfdata.log
2012-07-27 12:22:17 [28369] [0] *** TIMEOUT: Please check your npcd.cfg
2012-07-27 12:22:17 [28369] [0] *** TIMEOUT: /usr/local/nagios/var/spool/perfdata//1343384519.perfdata.service-PID-28369 deleted
2012-07-27 12:22:17 [28369] [0] *** Timeout while processing Host: "xxxx-TS" Service: "Page_File_Usage"
2012-07-27 12:22:17 [28369] [0] *** process_perfdata.pl terminated on signal ALRM
2012-07-27 12:22:17 [28368] [0] *** TIMEOUT: Timeout after 5 secs. ***
2012-07-27 12:22:17 [28368] [0] *** TIMEOUT: Deleting current file to avoid NPCD loops
2012-07-27 12:22:17 [28368] [0] *** TIMEOUT: Please check your npcd.cfg
2012-07-27 12:22:17 [28368] [0] *** TIMEOUT: /usr/local/nagios/var/spool/perfdata//1343384504.perfdata.service-PID-28368 deleted
2012-07-27 12:22:17 [28368] [0] *** Timeout while processing Host: "xxxx-NAS" Service: "System_Uptime"
2012-07-27 12:22:17 [28368] [0] *** process_perfdata.pl terminated on signal ALRM
tail -f /usr/local/nagios/var/npcd.logtail -f /usr/local/nagios/var/npcd.log
tail: cannot open `/usr/local/nagios/var/npcd.logtail' for reading: No such file or directory
==> /usr/local/nagios/var/npcd.log <==
[11-03-2012 17:23:31] NPCD: HINT: load_threshold is enabled - ('10.000000')
[11-03-2012 18:27:55] NPCD: Caught Termination Signal - Hasta la vista... baby
[11-03-2012 18:27:55] NPCD: npcd Daemon (0.4.14) started with PID=21520
[11-03-2012 18:27:55] NPCD: Please have a look at 'npcd -V' to get license information
[11-03-2012 18:27:55] NPCD: HINT: load_threshold is enabled - ('10.000000')
[11-03-2012 19:22:32] NPCD: Caught Termination Signal - Hasta la vista... baby
[11-03-2012 19:23:46] NPCD: npcd Daemon (0.4.14) started with PID=1498
[11-03-2012 19:23:46] NPCD: Please have a look at 'npcd -V' to get license information
[11-03-2012 19:23:46] NPCD: HINT: load_threshold is enabled - ('10.000000')
[11-05-2012 08:56:34] NPCD: WARN: MAX load reached: load 24.020000/10.000000 at i=0[11-05-2012 08:56:49] NPCD: WARN: MAX load reached: load 24.960000/10.000000 at i=1[11-05-2012 08:57:04] NPCD: WARN: MAX load reached: load 19.650000/10.000000 at i=1[11-05-2012 08:57:19] NPCD: WARN: MAX load reached: load 15.520000/10.000000 at i=1[11-05-2012 08:57:34] NPCD: WARN: MAX load reached: load 12.300000/10.000000 at i=1[11-05-2012 10:04:04] NPCD: WARN: MAX load reached: load 16.640000/10.000000 at i=0[11-05-2012 10:04:19] NPCD: WARN: MAX load reached: load 13.310000/10.000000 at i=1[11-05-2012 10:04:34] NPCD: WARN: MAX load reached: load 10.590000/10.000000 at i=1[11-05-2012 15:57:49] NPCD: WARN: MAX load reached: load 18.080000/10.000000 at i=0[11-05-2012 15:58:04] NPCD: WARN: MAX load reached: load 14.300000/10.000000 at i=1[11-05-2012 15:58:19] NPCD: WARN: MAX load reached: load 11.270000/10.000000 at i=1