Request for Guidance on Upgrading from 2.4.x(BDB with ppolicy) to 2.6.9

Dear LDAP Community,

We are planning to upgrade our setup from OpenLDAP 2.4.x to 2.6.9 (latest version) and would appreciate your guidance on the following:

Is a direct upgrade from 2.4.x to 2.6.9 possible, or are there intermediate steps required? We are currently using BDB with ppolicy. Does 2.6.9 support BDB, or is migration to MDB mandatory? Is ppolicy still supported in 2.6.9? Are the ppolicy module and schema included in 2.6.9, or do they need to be obtained externally? If a migration from BDB with ppolicy to MDB with ppolicy is required, could you kindly provide step-by-step guidance?

We greatly appreciate any insights, documentation, or recommendations you can share.

Thank you for your support! Regards, Anil P