How to fix failing Open Directory (database "cn=authdata" cannot be opened, err 12) after hang

Check if the OD database is the problem

$ sudo /usr/libexec/slapd -Tt

No further action is needed if the output tells something like:

...
bdb_db_open: database "dc=hostname,dc=domainname,dc=tldname": recovery skipped in read-only mode. Run manual recovery if errors are encountered.
...

Try repair

To repair the Open Directory authdata database:

$ sudo launchctl unload /System/Library/LaunchDaemons/org.openldap.slapd.plist

Now start the database recovery using the command below that matches your OS version.

$ sudo db_recover -h /var/db/openldap/authdata/ # Mac OS X 10.7
$ sudo db_recover -h /var/db/openldap/openldap-data/ # Mac OS X 10.6

Now slapd in tool mode outputs:

$ sudo /usr/libexec/slapd -Tt
bdb_db_open: database "dc=nl2,dc=probackup,dc=nl": unclean shutdown detected; attempting recovery.
bdb_db_open: database "dc=nl2,dc=probackup,dc=nl": recovery skipped in read-only mode. Run manual recovery if errors are encountered.
bdb_monitor_db_open: monitoring disabled; configure monitor database to enable
config file testing succeeded

Now turn back on Open Directory:

$ sudo launchctl load /System/Library/LaunchDaemons/org.openldap.slapd.plist

And issue another restart to be better safe than sorry:

$ sudo reboot

Open Directory should now be up and running again. In case it isn't running, try below.

Try Time Machine restore

First have a look at the available back-upped versions:

$ ls /Volumes/Time\ Machine/Backups.backupdb/*/

Pick the most recent version when Open Directory was still running correctly, for example 2018-07-22-091106.

Start again with unloading the daemon.

$ sudo launchctl unload /System/Library/LaunchDaemons/org.openldap.slapd.plist

Then remove (or rename) the database directory (when it is available Time Machine won't restore correctly) and start restore:

$ sudo rm -rf /var/db/openldap/ && sudo tmutil restore -v /Volumes/Time\ Machine/Backups.backupdb/*/2018-07-22-091106/Macintosh\ HD/var/db/openldap/ /var/db/

Force repair the database:

$ sudo db_recover -cv -h /var/db/openldap/openldap-data/

Repair permissions and reboot:

$ sudo diskutil repairPermissions / && sudo reboot

This is how I usually repair a broken LDAP/OD

1. check if this is the problem

sudo /usr/libexec/slapd -Tt*

You might get: bdb_db_open: database "cn=authdata": db_open(/var/db/openldap/authdata/id2entry.bdb) failed: Invalid argument (22).

2. Stop LDAP on OD Master

sudo launchctl unload /System/Library/LaunchDaemons/org.openldap.slapd.plist

3. Repair Permissions

diskutil repairPermissions /

4. backup openldap db

sudo cp /var/db/openldap/authdata/id2entry.bdb /var/db/openldap/authdata/id2entry.bdb.backup

5. repair

sudo db_recover -cv -h /var/db/openldap/openldap-data/

6. run repair again to check

sudo db_recover -cv -h /var/db/openldap/openldap-data/

7. do it one more time so things are repaired correctly

sudo /usr/libexec/slapd -Tt

8. restart the service

sudo launchctl load /System/Library/LaunchDaemons/org.openldap.slapd.plist

9. If the above does not work, try:

sudo db_recover -cv -h /var/db/openldap/authdata/

then I restart the service with step 8.

sudo launchctl load /System/Library/LaunchDaemons/org.openldap.slapd.plist

This usually fixes the problem... but in some cases you need to restore like llange explaines in his post.

First best is to check the disk you may do so either using the recovery partition or single user (cmd - S at startup) then type :

fsck -fy

QWERTY keyboard the dash is 2 key left from backspace.

To re-import a corrupted database from a backup you should backup and replace the following files/ folders :

• var/db/openldap/
• usr/bin/db_recover

Not sure it's necessary but if you have removed the LDAPv3 entry in the System keychain :

• Library/Keychains/System.keychain

The try a recovery…

Then you should repair disk permissions from a terminal (not single user) :

diskutil repairPermissions /

If after the recovery you experience problem connecting to services check the configuration under "Services" tab in Directory Utility.