diff --git a/_config.yml b/_config.yml
index cec63e8..02d3e80 100644
--- a/_config.yml
+++ b/_config.yml
@@ -41,6 +41,10 @@ feed:
 
 textile_ext: "textile,txtl,tl"
 
+# TODO: plugin jekyll-professorize with patches:
+# - setting default ext other than .md
+# - adding figurecaption to {% highlight %} figure
+
 # Exclude from processing.
 # The following items will not be processed, by default.
 # Any item listed under the `exclude:` key here will be automatically added to
diff --git a/_drafts/openldap-2-4-to-2-6-upgrade.tl b/_drafts/openldap-2-4-to-2-6-upgrade.tl
new file mode 100644
index 0000000..08882ce
--- /dev/null
+++ b/_drafts/openldap-2-4-to-2-6-upgrade.tl
@@ -0,0 +1,87 @@
+---
+layout: post
+title: OpenLDAP 2.4 to 2.6 upgrade
+---
+OpenLDAP >= 2.5 drops Berkeley DB based @hdb@ and @bdb@ backends support. Backend
+upgrade - preferably to @mdb@ - is required before version upgrade.
+
+Below instructions are given for _slapd.conf_ deployments. For _slapd-config_
+deployments the config database must be exported via @slapcat@, config export
+modified as required, then resulting config database imported.
+
+Upstream documentation:
+* "B. Upgrading from 2.x":https://www.openldap.org/doc/admin25/appendix-upgrading.html
+
+
+h2. Backup database and configuration
+
+{% highlight bash %}
+/etc/init.d/slapd stop
+
+cp -a /etc/openldap /etc/openldap-2.4
+
+slapcat -f /etc/openldap/slapd.conf > /var/backups/openldap/slapcat-2.4.ldif
+
+mv /var/lib/openldap-data /var/lib/openldap-data-2.4
+{% endhighlight %}
+
+
+h2. Migrate to @mdb@ backend
+
+Update _/etc/openldap/slapd.conf_ as follows:
+
+{% highlight config %}
+...
+# moduleload  back_hdb.so
+moduleload  back_mdb.so
+...
+database       mdb
+...
+{% endhighlight %}
+
+Then restore database and convert config to directory format (in that order):
+
+{% highlight bash %}
+mkdir /var/lib/openldap-data
+chmod --reference /var/lib/openldap-data-2.4 /var/lib/openldap-data
+slapadd -f /etc/openldap/slapd.conf -l /var/backups/openldap/slapcat-2.4.ldif
+find /var/lib/openldap-data/ -exec chown --reference /var/lib/openldap-data {} \;
+cp -a /var/lib/openldap-data-2.4/.keep_* /var/lib/openldap-data/
+
+rm -r /etc/openldap/slapd.d/*
+slaptest -f slapd.conf -F slapd.d
+
+/etc/init.d/slapd start
+{% endhighlight %}
+
+Now is the time to verify if LDAP dependent services work like before migration.
+They should.
+
+
+h2. Upgrade to 2.6
+
+Before upgrade:
+* check @openldap@ @USE@ flags,
+* backup database and configuration if applicable
+
+then proceed with upgrade:
+
+{% highlight bash %}
+emerge -1av openldap
+dispatch-conf
+{% endhighlight %}
+
+Remove @ppolicy@ overlay, which is now implemented internally:
+
+{% highlight config %}
+...
+#include    /etc/openldap/schema/ppolicy.schema
+...
+{% endhighlight %}
+
+Once again rebuild directory config:
+
+{% highlight bash %}
+rm -r /etc/openldap/slapd.d/*
+slaptest -f slapd.conf -F slapd.d
+{% endhighlight %}