3.11. Restoring the Directory Services Database

If the local directory database is damaged, boot into single-user mode by holding down

-S as the system starts up. Next, check to see if you have a backup of the NetInfo database. The /etc/daily cron job backs up the database each time it is run. You can find the backup in /var/backups/local.nidump. If you don't have a backup, you won't be able to restore. The local.nidump file is overwritten each time the cron job runs, so make sure you back it up regularly (preferably to some form of removable media).

If your computer is generally not turned on at 3:15 a.m. (the default time for the daily cron job), you'll never get a backup of your local directory. You can solve this problem by editing /etc/crontab to run this job at a different time, or to run the job periodically with the command sudo periodic daily. see Section 2.3.1 in Chapter 2 for more details.