A disk used by the operating system for performing I/O operations is divided into contiguous areas called partitions. A partition can be used as a file system area provided by the operating system or as a HiRDB file system area. Figure 6-1 shows the relationship between HiRDB file system areas and file system areas provided by the OS.

Figure 6-1 Relationship between HiRDB file system areas and file system areas provided by the OS

HiRDB file system areas can be created as character special files or as regular files. Character special files are recommended in order to improve the reliability of updating processes.

We recommend that you create a separate HiRDB file system area for each of the items listed and described in Table 6-2. For details about how to design the various HiRDB file system areas, see the HiRDB Version 8 Installation and Design Guide.

Table 6-2 Type of HiRDB file system area

Type of HiRDB file system area	Option1	Description
RDAREA	DB	HiRDB file system area in which RDAREAs (other than list RDAREAs) are stored. This area is always needed.
Shared RDAREA	SDB	HiRDB file system area in which shared RDAREAs are created. This area is needed if you use shared RDAREAs.
System file	SYS	HiRDB file system area in which system log files, synchronization point dump files, and status files are stored. This area is always needed.
Audit trail file		HiRDB file system area in which audit trail files are created. This area is needed to use the security audit facility.
Work table file2	WORK	HiRDB file system area in which work table files are stored. This area is always needed.
Utility	UTL	HiRDB file system area in which files used by utilities (backup files, unload data files, unload log files, index information files, or differential backup management files) are created.
List RDAREA3	WORK	HiRDB file system area in which list RDAREAs are stored. This area is needed to perform narrowed searches.

¹ The value of the -k option specification that is specified when you create a HiRDB file system area with the pdfmkfs command.

² With the Linux version of HiRDB, you cannot create a HiRDB file system area for work table files that is defined as a character special file.

³ With the Linux version of HiRDB, you cannot create a list RDAREA in a HiRDB file system area that you have created in a character special file.

The pdfmkfs command is used to create a HiRDB file system area.

Reference note

If you use either of the following environment setup support tools the first time you install HiRDB, a HiRDB file system area will be created based on the information you enter:

• Simple setup tool
• System generator (pdgen)

For details about designing and creating HiRDB file system areas, see the HiRDB Version 8 Installation and Design Guide.

The maximum size of an ordinary HiRDB file system area is approximately 2 gigabytes. A HiRDB file system area that exceeds this size limitation must be created as a large file. The maximum size of a HiRDB file system area created as a large file depends on the operating system version of HiRDB, as shown in Table 6-3.

Table 6-3 Maximum size of a HiRDB file system area

OS	Condition		HiRDB file system area maximum size (MB)
HP-UX version	Large files not used	Regular file	2,047
		Character special file
	Large files used	Regular file	131,071
		Character special file
Solaris version	Large files not used	Regular file	2,047
		Character special file
	Large files used	Regular file	1,048,575
		Character special file
AIX 5L version	Large files not used	Regular file	2,047
		Character special file
	Large files used	Regular file (JFS)	65,411
		Regular file (JFS2)	1,048,575
		Character special file
Linux version	Large files not used	Regular file	2,047
		Character special file
	Large files used	Regular file	1,048,575
		Character special file

Creating a large file

The procedure for creating a large file is the same as for creating a normal HiRDB file system area; you simply specify the HiRDB file system area's size (2 gigabytes or greater) in the -n option of the pdfmkfs command. When large files are to be used, Y must be specified in the pd_large_file_use operand of the system common definition.