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 Chapter 16. Determining RDAREA Size.
3. If you use the system switchover facility, create unload log files on a shared disk (character special files).
4. 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 record count for system log file to be unloaded^#1 system log file record size)^#2 number of unload log files to be created 1.2 1,048,576
     
   • -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 24.

   #1

   If you are using the system log file automatic extension facility, calculate this number using the value specified as the upper limit for expansion in the pd_log_auto_expand_size operand.

   #2

   This is the approximate value of the system log file.

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

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.