There are a number of ways you can do this using the Stand-Alone Program Loader (SAPL) screen at IPL time. You can optionally display this screen by specifying a 3270-capable console address in the LOADPARM field of your hardware console (or on the IPL command).
Rather than specifying the starting cylinder, you can specify the "extent number" of the parm disk on the IPL volume that you want to use. If you are using the CF1, CF2, and CF3 disks that are built when you install z/VM, CF1 is extent 1, CF2 is extent 2, and CF3 is extent 3 on the installed IPL volume. You can also have multiple system configuration files on the same parm disk (with different names of course). SYSTEM CONFIG is the default filename and filetype of the configuration file, but you can use different names as long as you tell CP which file to use. Using this method, you could: 1) Create a backup copy of the current SYSTEM CONFIG in a file called SYSBACK CONFIG (for example). 2) Make your changes to file SYSTEM CONFIG and IPL. 3) If need be, you can revert to SYSBACK CONFIG by specifying fn=SYSBACK in the IPL Parameters section of the SAPL screen when you re-IPL. John Franciscovich z/VM Development >Folks, > I've been informed that we're moving to new physical dasd >probably next week. So, I think this will work but was looking for >verification.... > > Backup current System config to from cf1 to cf2. > Change system config to new CUA's. We're moving one for one 2000 - 4000. > Update CF1 > Shutdown z/VM. > Reboot. > IF, repeat, IF I did it correctly and or there are no other >problems then fine. >BUT, if there are problems, I may need to return to the original >system config. THAT's where I want to make sure I understand this >right. I can at z/VM load time, change the parm disk from CF1 to CF2 >by specifying the starting cylinder, correct? AND that is the only >change I need to do to come up on a different disk. >
