NIS+ to LDAP Migration Scenarios

Likely scenarios for a migration from NIS+ to LDAP include the following.

• Convert all NIS+ clients to LDAP in one operation. You can use the rpc.nisd daemon to upload any NIS+ data that does not yet exist in LDAP. See How to Convert All NIS+ Data to LDAP in One Operation.

• Do a gradual migration from NIS+ to LDAP. Start by converting NIS+ data to LDAP (see How to Convert All NIS+ Data to LDAP in One Operation). You could have both NIS+ and LDAP clients sharing the same naming service data, and let the rpc.nisd automatically keep NIS+ and LDAP data synchronized. Initially, perhaps, NIS+ would be authoritative, and the LDAP server(s) would maintain a duplicate of the NIS+ data for the benefit of LDAP clients. At a convenient time, LDAP can become the authoritative naming service, and NIS+ service gradually phased out, until there are no more NIS+ clients.

• LDAP is already used as a naming service, so you need to merge the NIS+ and LDAP data. There are three possible ways to perform this merge.

  • Add the NIS+ data to LDAP. Entries that exist in NIS+, but not in LDAP, are added to LDAP. Entries that appear both in NIS+ and LDAP, but with different data, end up with the NIS+ data. See How to Convert All NIS+ Data to LDAP in One Operation.

  • Overwrite the NIS+ data with the LDAP data. If there are entries that exist in NIS+ but not in LDAP, they will disappear from NIS+. Entries that exist both in NIS+ and LDAP end up with the LDAP data. See How to Convert All LDAP Data to NIS+ in One Operation.

  • Merge NIS+ and LDAP data, resolving conflicts on an individual basis. See Merging NIS+ and LDAP Data.

How to Convert All NIS+ Data to LDAP in One Operation

1. Use the rpc.nisd to upload any NIS+ data that does not yet exist in LDAP.

   Assuming all NIS+/LDAP data mappings have been established in the default location (/var/nis/NIS+LDAPmapping), use the following command.

   # /usr/sbin/rpc.nisd -D \

   —x nisplusLDAPinitialUpdateAction=to_ldap \

   -x nisplusLDAPinitialUpdateOnly=yes

   The above would make the rpc.nisd upload data to LDAP, and then exit. The NIS+ data would be unaffected by this operation.

   See the nisplusLDAPinitialUpdateAction attribute on rpc.nisd(4).

How to Convert All LDAP Data to NIS+ in One Operation

1. Use the rpc.nisd to download all LDAP data to NIS+, overwriting existing NIS+ data.

   Assuming all NIS+/LDAP data mappings have been established in the default location (/var/nis/NIS+LDAPmapping), use the following command.

   # /usr/sbin/rpc.nisd -D \

   -x nisplusLDAPinitialUpdateAction=from_ldap \

   -x nisplusLDAPinitialUpdateOnly=yes

   The above would make the rpc.nisd daemon download data from LDAP, and then exit. The LDAP data would be unaffected by this operation.

   See the nisplusLDAPinitialUpdateAction attribute on rpc.nisd(4).