The Replication Changelog backend keeps changes from all directory servers for 24 hours by default. After this time period, also known as the purge delay, the backend is trimmed automatically.

In addition, within the userRoot and other local DN backends, attribute-level changes are recorded for a short period of time in the ds-sync-hist attribute of the entry targeted by an LDAP Modify operation. This attribute is used to resolve all conflicts resulting from LDAP Modify operations automatically.

The disk space impact of replication is dependent on the rate and size of changes in the replication topology and the Replication Changelog purge delay.