ITS#9666 - Add 2.5 to 2.6 upgrade information

doc/guide/admin/appendix-upgrading.sdf

@@ -2,73 +2,21 @@
 # Copyright 2007-2021 The OpenLDAP Foundation, All Rights Reserved.
 # COPYING RESTRICTIONS APPLY, see COPYRIGHT.
 
-H1: Upgrading from 2.4.x
+H1: Upgrading from 2.5.x
 
 The following sections attempt to document the steps you will need to take in order 
-to upgrade from the latest 2.4.x OpenLDAP version.
+to upgrade from the latest 2.5.x OpenLDAP version.
 
 The normal upgrade procedure, as discussed in the {{SECT:Maintenance}} section, should 
 of course still be followed prior to doing any of this.
 
-H2: {{B:cn=config}} olc* attributes
-
-The {{olcMirrorMode}} attribute has been renamed to {{olcMultiProvider}}.  Existing configurations
-will continue to work with the old parameter name, but it is advised to update to the new name as a
-part of the upgrade process.
-
 H2: ppolicy overlay
 
-The overlay now implements version 10 of the ppolicy draft in full. This includes the notion of a password
-administrator where applicable (as determined by having a {{manage}} permission to the {{userPassword}} attribute)
-and skips certain processing when there is no valid policy in effect or where the operation is initiated by
-a password administrator. Many attributes are now tagged with {{NO-USER-MODIFICATION}} in the schema, requiring
-the use of {{relax}} control to modify them.
-
-In OpenLDAP 2.4 the {{slapo-ppolicy}}(5) overlay relied on a separate schema file to be included for it to function.
-This schema is now implemented internally in the slapo-ppolicy module. When upgrading {{slapd.conf}}(5) deployments
-the include statement for the schema must be removed.  For {{slapd-config}}(5) deployments, the config database
-must be exported via slapcat and the old ppolicy schema removed from the export.  The resulting config database
-can then be imported.
-
-H2: unique overlay
-
-In OpenLDAP 2.4 it was possible to bypass {{slapo-unique}}(5) checks by using the manageDSAIT control as a part of the
-request. This is no longer possible. To achieve the same functionality the relax control must be used instead, and the
-binding identity must have manage permissions on the entry being modified.
-
-With OpenLDAP 2.5 a new keyword "serialize" has been added as a part of the unique_uri configuration parameter. This
-will cause all write operations requiring uniqueness to be serialized so as to avoid the scenario where multiple
-concurrent updates can prevent uniqueness from being enforced. See the {{slapo-unique}}(5) man page for further details.
-
-H2: ldap and meta backends
-
-Several deprecated configuration directives for {{slapd-ldap}}(5) and {{slapd-meta}}(5) have been removed. Configurations
-using those directive must be updated to use supported directives prior to upgrade.  See the {{slapd-ldap}}(5) and
-{{slapd-meta}}(5) man pages from OpenLDAP 2.4 for a list of deprecated directives.
-
-H2: shell backend
-
-This deprecated backend has been removed from OpenLDAP 2.5. Configurations making use of this backend must remove it
-prior to upgrade. The {{slapd-sock}}(5) backend is recommended as an alternative.
-
-H2: perl and sql backends
-
-The {{slapd-perl}}(5) and {{slapd-sql}}(5) backends are now deprecated and no longer automatically enabled with
-the --enable-backends configure flag.
-
-H2: hdb and bdb backends
-
-The Berkeley DB based slapd-bdb and slapd-hdb backends have been removed from OpenLDAP 2.5. Deployments making use
-of these backends must migrate their configurations to use {{slapd-mdb}}(5) prior to upgrade.
-
-H2: mdb backend
-
-It is advised to determine if the new {{slapd-mdb}}(5) idlexp backend directive and/or
-the multival database directive should be added to the OpenLDAP 2.5 configuration as well as the existing global
-sortvals directive. Configuring any of these items requires that existing databases be reloaded for them to take full
-effect. This can be done separately from the overall upgrade from OpenLDAP 2.4 to OpenLDAP 2.5 if desired.
+The pwdCheckModule option has been moved to the overlay configuration. Existing settings in password policy entries
+will be ignored. It will be necessary to add this configuration directive to the overlay when upgrading if it is
+currently in use.
 
-H2: Client utility changes
+H2: lloadd backends
 
-The deprecated "-h" (host) and "-p" (port) options for the ldap client utilities have been removed. It is required to
-use a properly formatted LDAP URI with the "-H" option in OpenLDAP 2.5 and later.
+Backends for lloadd are now grouped in tiers specifying the balancing strategy. OpenLDAP 2.5 configurations must be
+updated to account for this change.