"root" (/) file system

 

The "root" (/) file system takes full advantage of the stream file support and hierarchical directory structure of the integrated file system. It has the characteristics of the DOS and OS/2^® file systems.

In addition, it:

• Is optimized for stream file input and output.

• Supports multiple hard links and symbolic links.

• Supports local sockets.

• Supports threadsafe APIs.

• Supports *FIFO objects.

• Supports the /dev/null and /dev/zero *CHRSF objects as well as other *CHRSF objects.

• Supports the journaling of object changes.

• Supports the scanning of objects using the integrated file system scan-related exit points.

The "root" (/) file system has support for the character special files (*CHRSF) called /dev/null and /dev/zero. Character special files are associated with a device or resource of a computer system. They have path names that appear in directories and have the same access protection as regular files. The /dev/null or /dev/zero character special files are always empty, and any data written to /dev/null or /dev/zero is discarded. The files /dev/null and /dev/zero have an object type of *CHRSF and can be used like regular files, except that no data is ever read in the/dev/null file, and the /dev/zero file always returns successfully with the data cleared to zeros.

 

Accessing the "root" (/) file system

The "root" (/) file system can be accessed through the integrated file system interface using either the i5/OS^® file server or the integrated file system commands, user displays, and APIs.

• Case-sensitivity in the "root" (/) file system
  The file system preserves the same uppercase and lowercase form in which object names are entered, but no distinction is made between uppercase and lowercase when the system searches for names.

• Path names in the "root" (/) file system
  Path names have specific form in the "root" (/) file system.

• Links in the "root" (/) file system
  Multiple hard links to the same object are allowed in the "root" (/) file system. Symbolic links are fully supported.

• Integrated file system commands in the "root" (/) file system
  All of the commands listed in the Accessing using CL commands topic and the displays described in the Accessing using menus and displays topic can operate on the "root" (/) file system. However, it might not be safe to use these commands in a multithread-capable process.

• Integrated file system APIs in the "root" (/) file system
  All of the APIs listed in the Performing operations using APIs topic can operate on the "root" (/) file system.

• Object changes journaling in the "root" (/) file system
  Objects in the "root" (/) file system can be journaled. This function enables you to recover the changes to an object that have occurred since the object was last saved.

• UDP and TCP devices in the "root" (/) file system
  The "root" (/) file system under the directory of /dev/xti will now hold two device drivers named udp and tcp.

 

Parent topic:

File systems