System data is IBM-supplied data that runs the hardware and software for your server. System data includes the Licensed Internal Code and i5/OS™ objects in QSYS, libraries, and directories.
The easiest way to save your system data is with menu option 22 of the GO SAVE command. This saves all of your system data as well as security data and configuration data.
SAVSYS SAVLIB LIB(*IBM) ACCPTH(*YES) SAV DEV('/QSYS.LIB/media-device-name.DEVD') + OBJ(('/QIBM/ProdData') + ('/QOpenSys/QIBM/ProdData')) + UPDHST(*YES)