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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 transation. 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. Use the ldapmodify command-line utility to add the nsslapd-db-durable-transactions attribute to the cn=config,cn=ldbm database,cn=plugins,cn=config entry, and set the value of this attribute to off.
    # ldapmodify -D "cn=Directory Manager" -W -p 389 -h -x
    dn: cn=config,cn=ldbm database,cn=plugins,cn=config
    changetype: modify
    add: nsslapd-db-durable-transactions
    nsslapd-db-durable-transactions: off
    For information on the syntax of the nsslapd-db-durable-transactions attribute, see the Red Hat Directory Server Configuration, Command, and File Reference.
  2. Restart the Directory Server.
    # systemctl restart