The backup unit is specified in an option of the database copy utility. Data can be backed up in the following units:
* Function applicable to HiRDB/Parallel Servers only.
Data should be backed up daily. If this is not possible, data should be backed up at the following times:
A backup file can be created in any server machine on which HiRDB is running. There is no requirement that a backup file be created in the same server machine where the RDAREAs being backed up are located. A server machine containing a device such as CMT or DAT may be used.
The server machine to be used to store a backup file can be specified in an option of the database copy utility (pdcopy command).
When an RDAREA is backed up without using the database copy utility, the following must be completed before the backup operation is started:
List RDAREAs cannot be backed up. There is no need to make such backups, because lists can be re-created easily as long as the tables used for the lists are available.
If a character special file is used for a backup file, the character special file must be placed in a HiRDB file system area for utilities. To do this, UTL must be specified in the -k option of the pdfmkfs command.
If a message reporting a disk space shortage is output during execution of the database copy utility even though ample disk space has been provided, the following are possible causes:
In such a case, specify use of large files or change the kernel parameter value. You can also avoid the problem by creating multiple backup files. However, if the OS does not support large files, you must keep the disk partition size to 2 GB or smaller to be able to handle multiple files.
You can use the pdbkupls command to check the backup information collected by the database copy utility. For example, you can check the information listed below (for details about the information that can be checked, see the manual HiRDB Version 8 Command Reference):
Do not restore from backup information collected by the database copy utility on another HiRDB. For the method of migrating data to another HiRDB, see 12.1 Migrating a table to another HiRDB system.