The mksysb command create a bootable image of all mounted file systems on the rootvg volume group. The root volume group image is in backup file format, starting with data files and then any optional map files. The image file contains information describing the image installed during the BOS installation process. This information includes the names, sizes, maps and mount points of logical volumes and file systems in the rootvg. Command to take backup of aix operating system in tape drive is
mksysb -e /dev/rmt0.