I am trying to test picketlink with RH Directory server 9.1. At this moment, most of operations doesn't work. Reason is in the fact that RHDS doesn't seem to support "entryUUID" as unique attribute, instead the name of unique attribute is "nsuniqueid" (In my debugging session I was able to access "nsuniqueid" as attribute in ldap search).

Related bugzilla which I found for RHDS: https://bugzilla.redhat.com/show_bug.cgi?id=220222