Database log file storage
The Content Manager OnDemand database includes recovery logs which are used to recover from application or system errors. In combination with database backups, they are used to recover the consistency of the database right up to the point in time when an error occurs. Some logs, called active or primary logs, contain transactions which have not been committed to the database. These logs are stored in the primary database log path. Other logs, called archived or secondary logs, contain transactions which have been committed to the database. These logs are stored in the secondary database log path. Both types of logs can be used with database backups to enable forward recovery of the database to any point in time before a failure.
- If you are using Db2®, when a log fills, the database manager closes the full log and opens a new log. When all changes to the database have been made, the database manager closes the last log. After the load process disconnects from the database, Content Manager OnDemand copies the closed logs from the primary database log path to the secondary database log path. When you create a full backup image of the database with the arsdb command, Content Manager OnDemand deletes all of the logs from the secondary database log path. (When you create a full backup image of the database, it invalidates the secondary logs that were created before the time that the backup was taken.)
- If you are using SQL Server, when a log file fills, the database manager closes the full log file and opens a new log file, provided that you have configured the transaction log to use multiple log files. SQL Server also uses the auto grow feature to reduce the potential of running out of transaction log space. The log files are truncated after a successful backup of the transaction log and can be reused.
The amount of disk space that you need to store log files is a factor of the number and size of the log files and the length of time between full backups of the database.
When you install and configure Content Manager OnDemand, you set parameters that determine the number and size of the log files and where Content Manager OnDemand should store the log files.