Just a quick note to document the command to convert mksysb file into an ISO file. Useful for mounting a mksysb on an LPAR via a VIOS vopt device.
mkcd -m /path/to/mksysb.file -S -L -I /path/to/isodir
This will use the file system /mkcd/cd_fs by default as a temporary area to build the ISO, so it needs to be at least as big as the mksysb file. You can direct mkcd to use an alternative file system with the -C flag.