5.3. Disabling Durable Transactions

Durable transaction logging means that each LDAP update operation, comprised of a sequence of database operations in a transaction, is physically written to disk. Even though each LDAP operation can be comprised of multiple database operations, each LDAP operation is treated as a single database transaction. Each LDAP operation is both atomic and durable.


Turning off durable transactions can improve Directory Server write performance at the risk of data loss.
When durable transaction logging is disabled, every directory database operation is written to the database transaction log file but may not be physically written to disk immediately. If a directory change was written to the logical database transaction log file but not physically written to disk at the time of a system crash, the change cannot be recovered. When durable transactions are disabled, the recovered database is consistent but does not reflect the results of any LDAP write operations that completed just before the system crash.
By default, durable database transaction logging is enabled. To disable durable transaction logging:
  1. Stop the Directory Server instance:
    # dsctl instance_name stop
  2. Edit the /etc/dirsrv/slapd-instance_name/dse.ldif file, and set the nsslapd-db-durable-transaction parameter in the cn=config,cn=ldbm database,cn=plugins,cn=config entry to off:
    dn: cn=config,cn=ldbm database,cn=plugins,cn=config
    nsslapd-db-durable-transaction: off
  3. Start the Directory Server instance:
    # dsctl instance_name start