Red Hat DIRECTORY SERVER 7.1, Administrator'S Manual

Page: 484 / 652

Tuning Database Performance
484 Red Hat Directory Server Administrator’s Guide • May 2005
Changing the Location of the Database Transaction
Log
By default, the database transaction log file is stored in the
serverRoot
/slapd-
serverID
/db
directory along with the database files themselves.
Because the purpose of the transaction log is to aid in the recovery of a directory
database that was shut down abnormally, it is a good idea to store the database
transaction log on a different disk from the one containing the directory database.
Storing the database transaction log on a separate physical disk may also improve
directory performance.
To change the location of the database transaction log file, use the following
procedure:
1.
Stop the Directory Server.
For instructions, refer to “Starting and Stopping the Server from the Console,”
on page 37.
2.
Use the
ldapmodify
command-line utility to add the
nsslapd-db-logdirectory
attribute to the
cn=config,cn=ldbm
database,cn=plugins,cn=config
entry. Provide the full path to the log
directory in the attribute.
For information on the
nsslapd-db-logdirectory
attribute syntax, see the
Red Hat Directory Server Configuration, Command, and File Reference . For
instructions on using
ldapmodify
, refer to “Adding and Modifying Entries
Using ldapmodify,” on page 58.
3.
Restart Directory Server.
Changing the Database Checkpoint Interval
At regular intervals, the Directory Server writes operations logged in the
transaction log to the disk and logs a checkpoint entry in the database transaction
log. By indicating which changes have already been written to the directory,
checkpoint entries indicate where to begin recovery from the transaction log, thus
speeding up the recovery process.
By default, the Directory Server is set up to send a checkpoint entry to the
database transaction log every 60 seconds. Increasing the checkpoint interval may
increase the performance of directory write operations. However, increasing the
checkpoint interval may also increase the amount of time required to recover