Directory Server provides a configurable feature that enables you to stop database updates on disk so that a file system snapshot can be taken safely.
When frozen mode is set, all configured databases are taken offline. Any internal operations in progress are notified of the database going offline. LDAP operations in progress are completed, and the database environment is flushed. Subsequent incoming operations are refused until the server property is reset to read-write or read-only. In a single server topology, operations received when frozen mode is on result in an LDAP error being returned.
The standard error message for database offline is logged. In a replicated topology, a referral is returned. For this feature to work correctly, no other tasks should be running on the databases. Set the frozen mode using the dsconf set-server-prop command as follows:
dsconf set-server-prop read-write-mode:frozen
Once this property is set, you can safely take the file system snapshot.
See Backing Up a File System in Sun Java System Directory Server Enterprise Edition 6.3 Administration Guide for instructions on configuring frozen mode using command-line tools.