Preventing Your System from Restarting After a Full System Backup
May 16, 2012 Hey, Joe
Good article on the secrets of the IBM i IPL parameters. Is there a way to stop the system from restarting after my full system backups complete (GO SAVE, option 21)? There are times that it would be great for the system to stay in restricted state after a backup, but the startup CL program always runs. How do I stop it from running?
Here’s the drill for changing your System i and Power i partitions so that they don’t kick off their system startup programs after a GO SAVE, option 21, full system backup.
First, realize that using the Change IPL Attributes (CHGIPLA) command to change the Start to Restricted State IPL (STRRSTD) parameter to *YES has no effect on preventing system startup after a full system backup. That parameter is only used after a system IPL. The system pays no attention to STRRSTD on a restart after an option 21 save.
How The System Restarts After A Full System Backup
When an option 21 backup completes, it restarts your controlling subsystem, as defined in the Controlling Subsystem (QCTLSBSD) system value. In most cases, QSYS/QCTL will be the name of your controlling subsystem.
Inside the controlling subsystem, there is an Autostart Job Entry (AJE) called QSTRUPJD. The QSTUPRJD AJE starts a job based on a job description object (also named QSTRUPJD) that is configured to call a program named QWDAJPGM. To see what parameters your QSTRUPJD job description contains, run this Display Job Description (DSPJOBD) command.
Called from QSTRUPJD, QWDAJPGM checks the program and library names contained in the Startup Program (QSTRUPPGM) system value. If QWDAJPGM finds a valid program name in QSTRUPPGM, the program runs the QSTRUPPGM program and the system starts.
Given this process, the best way to stop your startup program from running is to change your system startup program name to *NONE, which will skip running a startup program altogether. Changing QSTRUPPGM to *NONE tells the system there is no startup program. The process of skipping your startup program after a full system backup consists of the following steps.
Here are the steps you can execute to make it happen.
Step #1: Change your startup program name to *NONE.
Before changing QSTRUPPGM to *NONE, be sure to make a spooled file copy of your existing QSTRUPPGM value for later use. You can do this by executing the following Display System Value (DSPSYSVAL) command.
DSPSYSVAL SYSVAL(QSTRUPPGM) OUTPUT(*PRINT)
After printing the startup program name, run this Change System Value (CHGSYSVAL) command to change the name of the startup program to *NONE.
CHGSYSVAL SYSVAL(QSTRUPPGM) VALUE(*NONE)
Step #2: Run your option 21 full system backup.
Run your full system backup by selecting option 21, entire system, off the Save (GO SAVE) menu. As your backup runs, it will put the system into restricted state, save the entire system, and then restart the system again by restarting your controlling subsystem. But because your Startup Program (QSTRUPPGM) system value is set to *NONE, the QWDAJPGM program will not run your system startup program.
Step #3: Change your QSTRUPPGM value back to its original startup program name.
At this point, you’ll have a quiet system that isn’t running anything except for your controlling subsystem. When you’re ready to restart your system, reset the QSTRUPPGM system value to your original system startup program name by executing this CHGSYSVAL command.
CHGSYSVAL SYSVAL(QSTRUPPGM) VALUE(LIB/PROGRAM)
Where LIB/PROGRAM equals the library and program name of your system startup program. Check the printout that you generated in Step #1, if you’re unsure of the original QSTRUPPGM name.
Step #4: End and restart your controlling subsystem.
After QSTRUPPGM is set back to its proper startup program name, put your subsystem back into restricted state by running the following End Subsystem (ENDSBS) command.
ENDSBS SBS(*ALL) OPTION(*IMMED)
Wait until your system is in restricted state before proceeding.
In restricted state, run this Start Subsystem (STRSBS) command to restart your controlling subsystem.
LIB/NAME equals the library and name of your controlling subsystem. When the subsystem restarts, it will once again autostart the QSTRUPJD job as detailed above and the QWDAJPGM program will run the startup program listed in the QSTRUPPGM system value.
Follow Joe On His Blog, On Twitter, And On LinkedIn
Come check out Joe Hertvik’s blog at joehertvik.com, where he focuses on computer administration and news (especially IBM i); vendor, marketing, and tech writing news and materials; and whatever else he come across.
Joe Hertvik is the owner of Hertvik Business Services, a service company that provides written marketing content and presentation services for the computer industry, including white papers, case studies, and other marketing material. Email Joe for a free quote for any upcoming projects. He also runs a data center for two companies outside Chicago. Joe is a contributing editor for IT Jungle and has written the Admin Alert column since 2002.