If your system setup is based on nscd with libnss-mysql and you have setup a cron job for a database user, it might be possible to get this error in your syslog after a reboot:
cron: Error: bad username; while reading /etc/cron...
This occurs because, on system startup, cron.service will try to start before mysql.service and nscd.service.
On Debian Jessie, which uses systemd service manager you could add a dependency for
cron.service to start after both
nscd.service are started.
mkdir -p /etc/systemd/system/cron.service.d echo -e "[Unit] After=mysql.service nscd.service" >> /etc/systemd/system/cron.service.d/dependency.conf
And don't forget to reload systemd daemon:
For a distro with SysVinit, you could update
/etc/init.d/cron to require mysql and nscd on start.
nano /etc/init.d/cron Change: # Required-Start: $remote_fs $syslog $time with # Required-Start: $remote_fs $syslog $time mysql nscd