The IBM i is a known stable and powerful platform and in the past I have had over 12 Domino servers on one IBM i partition, with only one Power five CPU, and about 16 GBs of memory (main storage) to keep them up and running. In the Windows world you will need 12 of those servers to keep all 12 Domino servers up. What a waste! Many companies that own Lotus and the IBM i don't put them together and end up putting Domino on Windows –the only explanation I can see is shear laziness. The IBM i was made for Lotus Domino and Lotus Domino was made for the IBM i and Power processors.
I will discuss some of the things you should consider when installing Domino on the IBM i, and once you get it running, you will never want to go back to any other OS, especially Windows.
Prerequisites for installing Domino on AS/400 systems
Note: I am using version 7 details, however, version 8 will be very similar but may require more steps, but this is a good place to start.
Disk space: For each Domino server install you will need on average two to three GB of space. The installation is not going to take up that much initially, but will require more space over time. It's better to have more space than you need initially, than not have enough in the end. I have done it both ways and it really depends on the version of Lotus Domino in your installation.
As for long term storage, you need to consider the quantity of mail you are going to allow each user. Are you going to place quotas on email boxes (let me advise you now, the answer is yes)? Establish these items before you build the server, and make sure you make it known so that six months from now no one is begging the IT Manager for more DASD because the limits were not put in place to begin with.
I would recommend you use a tiered system for mail. Three tiers would be sufficient.
- Tier 1: Normal Users = 500MB
- Tier 2: Above Average = 750MB
- Tier 3: Power Users = 1000MB
Keeping the mailbox size manageable is key. The larger email boxes get, the more problems you will see long term. Keeping them small will increase productivity of the IT staff and end users.
Base memory: Let's be honest, Lotus Domino is not a CPU bear, but it is a memory hog. Domino is going to need a fair amount of memory. For each Domino server you are going to want at least 700 MB free that you can give to it. The more memory Domino has the better, but there is a point where too much of a good thing can be bad. For example, on a mail server with 500 users, I would have about 2 GB of base memory for each Domino server doing mail. For application servers, Sametime servers and other Lotus products you will have to refer to the specifications. 2 GB is always a good starting point and seems to be a place where you can start tuning once Domino is up and running.
You might also want to build a second ASP if you are a performance nut and have the DASD to pull it off. Putting Domino's data in its own ASP is nice, but is not required.
Setting up Lotus Domino servers
The first step is deciding on your naming conventions for Domino partitions. This is not something you want to do on the fly, as it can be confusing down the road if it hasn't been well planned. If you only need one Domino server on your IBM i partition then you can name the Domino server the same thing. But, it can become confusing after a while because people don't separate the two. Giving the IBM i a system name like LOTUS or DOMINO and then naming the servers MAIL, APPS, etc. can also be done. Make sure names are apart of all pre-configuration discussions.
Upgrading: Upgrading Lotus Domino on the IBM i is a snap. I know you're all seasoned IT professionals, but I assure you after some years with the product the easiest thing I do as an administrator is upgrade Lotus Domino. All you have to do is upgrade the LICPGM for Lotus Domino, and then run a command on each server to upgrade it and you're done. In the past I have been able to upgrade about 10 Lotus Domino servers in under an hour, keep in mind I was doing them one at a time, wait for the current one to finish before I move on. These are but a few things to think about when installing Lotus Domino on the IBM i. I would highly recommend working with a reseller and reading the IBM Redbook Implementing IBM Lotus Domino 7 for i5/OS.
ABOUT THE AUTHOR: David Vasta is the Lotus Notes Administration Team Lead over North America at Atlas Copco. He has 17 years of data center and iSeries experience working in companies such as IBM, REAL and Cingular. He writes a regular blog at System i blogger.
This was first published in February 2009