File systems and logical volumes

A file is a one-dimensional array of bytes that can contain ASCII or binary information.

AIX® files can contain data, shell scripts, and programs. File names are also used to represent abstract objects such as sockets or device drivers.

Files are represented internally by index nodes (i-nodes). Within the journaled file system (JFS), an i-node is a structure that contains all access, timestamp, ownership, and data location information for each file. An i-node is 128-bytes in JFS and 512-bytes in the enhanced journaled file system (JFS2). Pointers within the i-node structure designate the real disk address of the data blocks associated with the file. An i-node is identified by an offset number (i-number) and has no file name information. The connection of i-numbers and file names is called a link.

File names exist only in directories. Directories are a unique type of file that give hierarchical structure to the file system. Directories contain directory entries. Each directory entry contains a file name and an i-number.

JFS and JFS2 are supported by this operating system. The file system links the file and directory data to the structure used by storage and retrieval mechanisms.