If automatic log backup is switched on, the database system continuously writes redo log entries to backup files (in chronological order). Thus the number of backup files on the hard disk keeps growing until there is no more storage space available.
If no more storage space for log backups is available on the hard disk, then after some time no more storage space for redo log entries is available in the log area of the database either, because old redo log entries can only be overwritten by the system with new entries after they have been backed up. Exception: Overwrite mode for the log area is activated; but this is not recommended for production systems. If the database system cannot write any more redo log entries to the log area, the database comes to a stand-still.
Therefore you need to ensure that there is always enough space available for log backups by moving your backup files to other hard discs or data carriers (archiving).
Locate the backup files.
More information: Backup Templates and Data Carriers
Example
You have defined the following backup template and activated automatic log backup:
Property |
Value |
---|---|
Name of the backup template |
MYLOG |
Backup type |
LOG |
Data carrier type |
FILE |
Data carrier (Device/File) |
DEMODB_MYLOG If you do not enter an absolute path, then the database system uses the run directory of the database. Example: C:\Documents and Settings\All Users\Application Data\sdb\data\wrk\DEMODB\ More information: Run directory |
Size of data carrier |
No restriction (blank or 0) |
Block size |
8 pages |
Overwritable |
No |
Your backup files are located in the run directory of the database:
DEMODB_MYLOG.001
DEMODB_MYLOG.002
DEMODB_MYLOG.003
DEMODB_MYLOG.004
DEMODB_MYLOG.005
Caution
If automatic log backup is activated, the system saves new log entries to the newest backup file even during archiving. To ensure that you only archive complete backup files, exclude the newest backup file during archiving.
To archive the backup files, use operating system commands to move the oldest backup files to another hard disk or data carrier.
If you use third-party backup tools, you can automate the archiving of backup files using Database Manager CLI or CCMS (only in SAP systems).
More information:
Database Manager CLI, Other Commands for Backups
Database Administration in CCMS, Archiving Backup Files