Admin Alert: Four Ways To Move An IBM i Partition, Part 1
December 4, 2013 Timothy Prickett Morgan
I’m currently working with a client to migrate three IBM i partitions to new Power 7+ machines located in two data centers in different states. While there are several ways to approach migration, over the next two issues I’ll discuss four specific techniques for moving an IBM i partition to a new location and the different tasks you have to perform for each technique.
Four Ways To Move An IBM i
In general, there are four techniques for moving an IBM i partition to a different machine:
This issue, I’ll look at the first two techniques. I’ll finish covering the third and fourth moves next issue. If you know of any other techniques, please feel free to email me.
There are pluses and minuses to all of these techniques. Let’s first look at the things you’ll need to do for all four move types.
What Every Move Needs
When moving any box to a different machine in another location, you’ll generally need to account for the following items.
Here are the first two ways you can move an IBM i partition to another Power i machine.
Technique #1: Restore the partition in place or to a new location using the same system name.
This is the traditional way of migrating to a new box. You take down the old box for the last time, perform a full system backup to media (usually tape), and then restore your old system to a new system using the backup media.
The only changes you need to make to get the partition up and running are to change what resources it uses, such as disk, network connections, media, IP addresses, etc.
If you have a HA solution for the partition you’re moving, you may opt to cut over to your backup system while restoring the main system so that you can keep processing running as usual.
The biggest down side of this technique is that you can’t bring up the new partition live alongside the old partition. This is particularly true if you’re using pieces from the old hardware to build the new machine, such as during an upgrade.
There’s nothing unusual about this technique. It’s what IBM i and older AS/400, System i, and iSeries shops have been doing for years. But the thing to notice about this technique is that it usually serves as the bedrock configuration for some of the other techniques. Nothing happens in many of the other techniques without first performing a restore from the old system.
Technique #2: Restore to a new location using a different system name.
This technique comes into play when you’re consolidating two different IBM i machines onto a single machine. If you’re simply moving the box to a new location with the same system name, IP address, etc., you’ll probably use the first technique described above.
But an IBM i partition move gets much more complicated if you decide to change your system name while you’re performing the move. One of my clients did this recently when they were eliminating an old System i machine and moving their partitions to a Power 7+ box in another city. They had decided to change the system name so that the old and new partitions could be active at the same time and they could test the new partition before switching over. In merger or acquisition situations, partition name changes are sometimes asked for in order to bring the system name in line with the acquiring company’s standards.
This technique starts the same way as scenario #1. You restore the old system to new hardware. Then you perform the traditional changes for new resource names, Ethernet lines, tape drives, etc.
The difference comes when you have to change all the unique IBM i, companion server, and network items that reference either your IP address or your IBM i system name. This is necessary to get your restored system functional again on the network.
To do that, here’s a partial list of all the system specific items that need to be changed and the green-screen commands to change them, when you rename an existing IBM i machine to a new system name.
The plus side of this technique is that you can set up and test your moved partition before it goes live, since it will be running at the same time as the partition it is replacing. You can more or less migrate at your leisure.
The downsides to this technique are the following:
So while you may get the benefit of carefully moving and evaluating your new partition before going live, it will entail a lot of redundant work and a fair amount of time to move and rename a system on another machine. Unless it’s a business requirement, I don’t normally recommend renaming a partition when you move it to a new machine.
Next issue: More techniques for moving an IBM i partition.
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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.