On a OSR6 system w/MP2 I have this line in user sys's crontab:

0,20,40 * * * * /usr/lib/sa/sa1

and in /etc/inittab there is this (I've broken the line so google
won't):

metr::sysinit:/sbin/sh -c '[ -x /sbin/metreg ] && \
/sbin/metreg' >/dev/console 2>&1

I've confirmed metreg gets run at boot time and that
/var/adm/metreg.data is created/updated. But after each boot, until I
run metreg manually, I get this error in email from cron each time sa1
runs:

sadc: Error opening metric registration file. File:'sadc.c', line:206

Permissions on metreg.data don't seem to be the problem.

Would some change to the running kernel, after metreg is run, cause
this problem? E.g., installing a loadable kernel module.