More about Directory Server and OpenDS Margin Notes

Backing up and restoring Directory Server data and configuration has become easier and better documented in the past few releases. Nevertheless, there are still some questions about how to back up both the directory data and the directory configuration.

First of all, if you are using a recent version of Directory Server you can use frozen mode and then perform file system snapshots. When you use Directory Server on Solaris 10 and put your data on ZFS, you can save and restore ZFS snapshots after you put Directory Server into frozen mode.

For Directory Server 6.x, you can put a server into frozen mode using the dsconf set-server-prop command.

dsconf set-server-prop -p 1389 read-write-mode:frozen

See the Solaris ZFS Administration Guide for more information on saving and restoring ZFS snapshots. You can even save onto and restore snapshots from a remote system, or use other backup software.

For Directory Server 6.x, you can put a server back into read-write mode using the dsconf set-server-prop command again.

dsconf set-server-prop -p 1389 read-write-mode:read-write

Otherwise, backing up Directory Server can be done online by bringing the server instance into a read-only state, backing up databases, configuration, and custom schema, and then bringing the server instance back into read-write state.

Do not make configuration changes while the server is being backed up, even though technically you can. (The configuration remains read-write while the rest of the server is read-only, because the configuration contains information about whether the server is read-write or read-only.)

1. Bring Directory Server into a read-only state.

   For Directory Server 6.x, you can put a server into read-only mode as follows.

   dsconf set-server-prop -p 1389 read-write-mode:read-only

   For Directory Server 5.x, you can modify the nsslapd-readonly attribute using the following LDIF.

   dn: cn=config
   changetype: modify
   replace: nsslapd-readonly
   nsslapd-readonly: on

   If the directory is replicated, this step will cause replication errors, by the way. Replication will attempt to continue, but will not be able to complete any operations.

2. Either backup to LDIF (more portable) or to binary backup (still somewhat portable for versions supporting binary copy).

   # 6.x LDIF backup
   dsadm export /path/to/ds dc=example,dc=com /safe/place/Example.ldif
   # 6.x binary backup
   dsadm backup /path/to/ds /safe/place
   # 5.x LDIF backup
   ServerRoot/slapd-instance/db2ldif -a /safe/place/Example.ldif -s dc=example,dc=com
   # 5.x binary backup
   ServerRoot/slapd-instance/db2bak. /safe/place

3. Copy the dse.ldif configuration file to a safe place.

   # 6.x
   cp /path/to/ds/config/dse.ldif /safe/place/
   # 5.x
   cp ServerRoot/slapd-instance/config/dse.ldif /safe/place/

4. Copy your specific schema modifications to a safe place.
   If you modified directory schema over LDAP, then your modifications are all in 99user.ldif. If you updated the schema by adding files, you might have a number of schema files that you must copy during this step, not just 99user.ldif.

   # 6.x
   cp /path/to/ds/config/schema/99user.ldif /safe/place/
   # 5.x
   cp ServerRoot/slapd-instance/config/schema/99user.ldif /safe/place/

5. Bring Directory Server back into a read-write state.

   For Directory Server 6.x, use the dsconf command.

   dsconf set-server-prop -p 1389 read-write-mode:read-write

   For Directory Server 5.x, you can modify the nsslapd-readonly attribute using the following LDIF.

   dn: cn=config
   changetype: modify
   replace: nsslapd-readonly
   nsslapd-readonly: off

Restoring Directory Server from backup potentially starts with a reinstall of both the operating system and also Directory Server with the same configuration as the original system. Having the same configuration is particularly important if you want to restore from binary backup. The following steps assume that you are restoring after a severe system failure.

1. Install both the operating system and also Directory Server with the same configuration as the original system.

2. Stop Directory Server and all application processes.

3. Overwrite the Directory Server configuration with the backup version.

   # 6.x
   cp /safe/place/dse.ldif /path/to/ds/config/
   # 5.x
   cp /safe/place/dse.ldif ServerRoot/slapd-instance/config/

4. Restore your schema modifications from backup.
   If you updated the schema by adding files rather than over LDAP, you might have a number of schema files that you must copy during this step, not just 99user.ldif.

   # 6.x
   cp /safe/place/99user.ldif /path/to/ds/config/schema/
   # 5.x
   cp /safe/place/99user.ldif ServerRoot/slapd-instance/config/schema/

5. Restore all non-replicated backend databases from LDIF or binary backup.

   If your directory data is replicated, consider restoring the data by initializing the replica from a supplier. See the documentation for your Directory Server version, [6.0] [5.2] [5.1], for more information.

   # 6.x LDIF restore
   dsadm import /path/to/ds /safe/place/Example.ldif dc=example,dc=com
   # 6.x binary restore
   dsadm restore /path/to/ds /safe/place
   # 5.x LDIF restore
   ServerRoot/slapd-instance/ldif2db -n example -i /safe/place/Example.ldif
   # 5.x binary restore
   ServerRoot/slapd-instance/bak2db /safe/place

6. Restart Directory Server and bring it into read-write state.

   # 6.x
   dsadm restart /path/to/ds
   dsconf set-server-prop -p 1389 read-write-mode:read-write
   # 5.x
   ServerRoot/slapd-instance/start-slapd
   ldapmodify -D "cn=Directory Manager" -w -
   Enter bind password: 
   dn: cn=config
   changetype: modify
   replace: nsslapd-readonly
   nsslapd-readonly: off

7. Reinitialize replication agreements restored if the Directory Server instance is a supplier.

8. Restart application processes on the system.