1. If you are creating a HiRDB file system area for backup files, allocate it to character special files.
2. The amount of space required for a HiRDB file system area for backup files must be greater than the total size of the RDAREAs that will be backed up. For details about the sizes of RDAREAs, see 17. Determining RDAREA Size.
3. Create a HiRDB file system area for differential backup management files on the server machine where the system manager is located.
4. If you use the system switchover facility, create unload log files on a shared disk (character special files).
5. If you are creating a HiRDB file system area for unload log files, specify the following options in the pdfmkfs command:
   
   • -k option: Specify UTL (HiRDB file system area for utilities) as the usage.
   • -n option: For the size of the HiRDB file system area, specify the value obtained from the following formula:
     Total number of records in system log files to be unloaded record length of system log files number of unload log files to be created 1.2 1048576
     
   • -l option: For the maximum number of files, specify the number of unload log files to be created.
   • -e option: For the maximum number of extensions, specify the number of unload log files to be created times 10.

You can use the following command to obtain the peak capacity of a HiRDB file system area for utilities:

pdfstatfs -d name-of-HiRDB-file-system-area-for-utilities

-d

Specifies that the maximum utilization value for the allocated HiRDB file system area is to be displayed. The peak capacity display that is output is this value. You can clear the maximum utilization value by entering the following pdfstatfs command:

pdfstatfs -c name-of-HiRDB-file-system-area-for-utilities

-c

Specifies that the maximum utilization value for the allocated HiRDB file system area is to be cleared to 0.