Tuning Database PerformanceChapter 14 Tuning Directory Server Performance 485directory databases after a disorderly shutdown and require more disk space dueto large database transaction log files. Therefore, you should only modify thisattribute if you are familiar with database optimization and can fully assess theeffect of the change.To modify the checkpoint interval while the server is running, use the ldapmodifycommand-line utility to add the nsslapd-db-checkpoint-interval attribute tothe cn=config,cn=ldbm database,cn=plugins,cn=config entry.For more information on the syntax of the nsslapd-db-checkpoint-intervalattribute, refer to the Red Hat Directory Server Configuration, Command, and FileReference. For instructions on using ldapmodify, refer to “Adding and ModifyingEntries Using ldapmodify,” on page 58.Disabling Durable TransactionsDurable transaction logging means that the temporary database transaction log is,in fact, physically written to disk.When durable transaction logging is disabled, every directory database operationis written to the database transaction log file but may not be physically written todisk immediately. If a directory change was written to the logical databasetransaction log file but not physically written to disk at the time of a system crash,you cannot recover the change. When durable transactions are disabled, therecovered database is consistent but does not reflect the results of any LDAP writeoperations that completed just before the system crash.By default, durable database transaction logging is enabled. To disable durabletransaction logging, use the following procedure:1. Stop the Directory Server.For instructions, refer to “Starting and Stopping the Server from theCommand-Line,” on page 38.2. Use the ldapmodify command-line utility to add thensslapd-db-durable-transactions attribute to the cn=config,cn=ldbmdatabase,cn=plugins,cn=config entry, and set the value of this attribute tooff.For information on the syntax of the nsslapd-db-durable-transactionsattribute, see the Red Hat Directory Server Configuration, Command, and FileReference. For instructions on using ldapmodify, refer to “Adding andModifying Entries Using ldapmodify,” on page 58.3. Restart the Directory Server.
