Volume Group Descriptor Area. It contains the information about volume group to which the physical volume belongs to. It also contains the information about physical partitions, logical partitions and logical volumes.
★ AIX is a multi-user system
★ When the user login he needs to provide the user name and password for authentication purposes.
★ After the successful login, AIX starts the SHELL program.
☆ As the user login to the AIX server, the AIX starts the SHELL program.
☆ The SHELL is a command interpreter.
☆ It takes the inputs from the users and executes it.
☆ SHELL is not only the command interpreter it also provide great flexibility to the user.
☆ SHELL not only read and execute the commands it also read the files written in the form of programs and executes them, these shell program files are known as SHELL scripts. The extension of SHELL script is .sh.
☛ Bash is the GNU shell
☛ Bash is an sh-compatible shell that incorporates useful features from the Korn shell (ksh) and C shell (csh).
☛ It is intended to conform to the IEEE POSIX P1003.2/ISO 9945.2 Shell and Tools standard.
☛ It offers functional improvements over sh for both programming and interactive uses.
☛ Interactive usage includes command line editing, unlimited size command history, job control, shell functions and aliases, indexed arrays of unlimited size, and integer arithmetic in any base from two to sixty-four. Bash can run most sh scripts without modification.
☷ sh or Bourne Shell
☷ bash or Bourne Again shell
☷ csh or C shell
☷ tcsh or Turbo C shell
☷ ksh or the Korn shell
Volume Group Status Area it contains the information about physical partition from all physical volumes of the same volume group. It contains the status of VG.
#chuser account_lock=true username
#backup -f /dev/rmt0
# restvg -x -d -f /dev/rmt0