Rebooting a box causes sysstat sar to report wrong data about the moment of reboot. This is because RedHat linux does not write the Linux-Reboot record (dummy record) to the sysstat statistics file. This causes wrong values if the data is evaluated later because most values decrease in case of reboot. sadc.c source says about the problem: /* *************************************************************************** * sadc called with interval and count parameters not set: * write a dummy record notifying a system restart. * This should typically be called this way at boot time, * before the cron daemon is started to avoid conflict with sa1/sa2 scripts. *************************************************************************** */ To fix, add something like [ -e /usr/lib/sa/sadc -a -x /usr/lib/sa/sadc ] && /usr/lib/sa/sadc to rc.sysinit after it is clear /var is mounted (at least when the other activities on /var start).
This is because the rpm does not contain the /etc/init.d/sysstat script (sysstat.sh in the tarball). It needs to be patched to play nice with chkconfig. Other than that, just a few lines in the spec file will fix this.
I consider this for future product versions.
fixed in 5.0.0-0.6