Admin Alert: More on Preparing for OS/400 V5R1 to V5R3 Upgrades
by Joe Hertvik
In my last column, I started documenting my experiences in upgrading a multi-partitioned OS/400 V5R1 machine to the i5/OS V5R3 operating system (which IBM also refers to as OS/400 V5R3). I covered several pre-installation tasks you need to perform, including retrieving installation manuals, reviewing any third-party software, and obtaining V5R3 PTFs. This week, I'll discuss some other important prep items that affect how long your upgrades will take, and what to do after the upgrade is complete.
Use the Installation Manual
As I mentioned last time, make sure you download and thoroughly study IBM's installation manual for OS/400 V5R3, Install, upgrade, or delete OS/400 and related software (in PDF format). (The manual can also be viewed and printed from the iSeries Information Center).
The installation manual is critical because it provides a checklist-style roadmap for prepping your OS/400 box for the upgrade and performing the upgrade; you will not be able to perform your installation without it.
Two Steps You Should Not Miss
In general, you shouldn't miss any steps in IBM's installation procedures but there are two new critical steps that IBM has added to a V5R3 upgrade.
First, IBM is now requiring that you install temporary Software Agreement PTFs before upgrading from OS/400 V5R1 or V5R2 to OS/400 V5R3. Once these PTFs are installed, there's a new required option to accept IBM's software licensing agreements before you can upgrade the operating system. If you do not install these PTFs and accept IBM's licensing terms, the system will not allow you to perform the upgrade.
The other critical step is to make sure you select IBM's new upgrade option to Allocate additional space for LIC. According to IBM, OS/400 V5R3's Licensed Internal Code requires an additional .42 GB of storage than in previous releases. When upgrading from an earlier operating system, this additional space must be allocated before the upgrade or the upgrade will stop part-way through the installation.
Plan Your Installation Time Carefully
The cardinal rule for OS/400 upgrades is to bring lunch and maybe even dinner (heck, I even wound up buying breakfast one morning when my upgrade unexpectedly ran overnight). When you count up all the activities involved in a V5R3 upgrade, you can easily spend eight hours or more on installation alone. Here are some of the time-consuming activities to keep in mind as you plan your OS/400 V5R3 upgrade schedule.
Do a Full System Backup
You will definitely want a complete backup of your entire machine, including the operating system, in case something goes wrong during the upgrade and you need to perform an emergency system restore. If you are working in a big shop where there is an operations staff, ask them to perform the backup the night before the upgrade. If not, you'll have to run the backup yourself.
Full system backups are performed by running option 21, Entire System, from the green-screen Save menu (GO SAVE). It's important to note that a full system backup can only run in restricted mode. So in addition to making your AS/400 or iSeries unavailable during the upgrade, you will have to restrict use during the full system backup, which can take several hours, depending on how much storage your system has and the speed of your backup media. For instructions on how to perform a full system backup, see "Admin Alert: Dissecting an Option 21 Save." And be sure to make it a point to clean your tape drives before performing an option 21 backup, in order to avoid problems caused by dirty drive heads.
Plan for Multiple IPLs During the Upgrade
During my upgrade, I found that I needed to perform at least three IPLs at the following times. One IPL is necessary before the upgrade begins in order to take care of a few final pre-upgrade tasks. As mentioned above, OS/400 V5R3 now requires you to allocate more space for the new operating system before you can perform the upgrade, a task that requires an IPL to complete (see the installation manual for details). A pre-upgrade IPL will also permanently apply temporary PTFs in order to reclaim OS/400 DASD.
A second IPL is necessary after the upgrade ends to apply the most recent cumulative PTFs for the operating system and to start the Initialize System (INZSYS) process.
A third IPL is necessary after the system initializes, if you want to apply HIPERs and Database group PTFs, which IBM sends out with the cumulative PTFs. You can also apply other group and individual PTFs to your system at this time.
Regarding PTF application after an upgrade, there is some confusion in IBM's documentation as to whether you can apply group and individual PTFs at the same time that you apply the cumulative PTFs. IBM tech support engineers have told me that these other PTFs should be applied after the INZSYS process ends and the cumulative PTFs have been applied. I have also heard this same recommendation from business partners who have installed V5R3 on a lot of machines. So applying non-cumulative group PTFs separately seems like the safe way to upgrade a system.
To speed up the first two IPLs, you can set your box to automatically IPL into restricted state, which will save you the time and trouble of shutting down active processes as you are performing the upgrades.
Plan Time for Unexpected Surprises
During one upgrade, my machine's cache battery died, which caused disk writes to take twice as long, and I wound up sweating out whether the system would be up by the end of the maintenance window. Another upgrade was preceded by a full system backup that failed on a media error, caused by a tape drive that needed to be cleaned. I had to restart the backup at the point of failure, which resulted in a two-hour delay.
The point is that upgrade maintenance windows can be tight, so you should request extra time for emergency tech support calls in case something unexpectedly goes wrong. For my systems, I generally try to let everyone know that the system will be unavailable for at least 12 hours. IBM also provides a checklist in the installation manual for calculating how long an upgrade will take.
Plan for Data Conversion and Object Decompression
After the upgrade completes, your system will run slowly as it finishes converting data to OS/400 V5R3 format and as it decompresses the new system objects it just installed. You may see extremely slow performance on your upgraded partitions right after the upgrade, but the slowness should end within an hour.
Know What's Involved in Your OS/400 IPL
After the upgrade completes, your last IPL will start the OS/400 startup program (as defined in the Startup Program system value, QSTRUPPGM), which launches your production jobs. For many shops, their iSeries or AS/400 may only be IPLed once a year, and the startup procedure may be a little murky or weak. So it's a good idea to get a copy of your startup program, review it to understand what jobs should be initialized at startup, and keep the startup program handy to help solve problems as they occur. For more information on startup programs, you can check out two earlier "Admin Alerts" on how to change your OS/400 startup program and how to locate and check your startup program job log.
You should also print out a copy of the Work with Active Jobs (WRKACTJOB) screen as it's running in production. Then, after your upgraded system is IPLed and ready to process, you can compare the listing from the normal production WRKACTJOB listing with the jobs that are running on the system after the upgrade. Where you see a reasonable difference, you can then take action to adjust the system or restart jobs that may have failed during the IPL.
At this point, when you've performed all your pre-installation tasks according to the installation manual and have estimated and arranged for an OS/400 V5R3 maintenance window, you're ready to start your upgrade. In a future column, I'll look at some issues that can occur while you're performing the installation and after the installation.
In the last "Admin Alert," entitled "Preparing for an OS/400 V5R1 to V5R3 Upgrade," the cumulative group PTF number for OS/400 V5R3 PTFs was misidentified as SF98530. The correct number is SF99530. IT Jungle regrets the error. [Correction made 01/17/05.]
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