Lukas Beeler’s IT Blog

Setting up and installing i5/OS takes awfully long (usually around 12 hours for a simple install alone, on cheaper machines), but it isn’t that difficult.

IBM offers a very nice and detailled PDF for this, and the whole information is also on the i5/OS Infocenter. IBM’s writing style is very convoluted, and you’ll need to make some jumps through the document to get all the information you need.

First, let’s talk about installing from scratch. When you buy a new machine, you usually don’t need to that because it comes preloaded with the current version of i5/OS and a decent PTF level. You might need to install additionally ordered software and reapply CUM PTFs, because IBM mostly doesn’t get the preinstall of additionally ordered software right (And unlike Windows Service Packs, you need to reapply CUM PTFs after installing new OS components).

But first things first. You need to change a few system values:

• QLMTSECOFR set this to 0 to allow QSECOFR to sign-on from any device.
• QSAVACCPTH set this to 0 for faster saves that need less space, but longer restore times.
• QCTLSBSD set this to QCTL to use a single controlling subsystem with different subsystems for different tasks, or leave it as QBASE for a single subsystem with everything in it.

These two changes are completely optional. Leave them be if you have made different decisions.

• DECFMT change this to the appropriate format for your country. In Switzerland, this is 1.
• QUPSDLYTIM set this to an appropriate time using the documentation for your UPS. 600 seconds is a good start. Never leave the default value.
• QCCSID this is the most important value. This needs to be set to the appropriate value for your country. For Switzerland, this is 500.
• QTIMZON also very important. I wrote about this earlier.
• QLOCALE almost as important as QCCSID - set it to the correct locale for your country. For Switzerland, this is /QSYS.LIB/DE_CH.LOCALE
• QRETSVRSEC needs to be set to 1 for ESA to work

All these chances are of the utmost necessity for a correctly working system. Even if you do live in the US, not all defaults are correct for you (QCCSID defaults to 65535, but should be 037 in the US).

Another important step is to use CHGNETA to change several important attributes, but before you do, decide on a hostname for the system. It doesn’t really matter what it is, but it needs to be consistent. One i’ve seen often is CCXXXXNN, where CC is the ISO country code, XXXX a shorthand for your company, and NN the number of the i5/OS instance. For example, we use CHDLAG01.

• SYSNAME, LCLNETID, LCLCPNAME need to be set to your hostname
• MDMCNTRYID needs to be set to your ISO Country Code - without this parameter set, your modems won’t work (If you still use them)

The next step is to configure your Ethernet line, and adding the appropriate IP address. The common pitfalls here are that people often forget to set a default route (CFGTCP, 2), or do not configure a hostname and the appropriate hosts table entry.

The systems TCP/IP hostname can be chosen arbitrarily, but we will use the same as we’ve used for the SYSNAME value of CHGNETA before, and just add our internal domain suffix. If you’re using Microsoft’s Active Directory, it makes sense to use a single namespace. For example our SYSNAME is CHDLAG01, and our Active Directory domain is int.dataline.ch, this gives us a TCP/IP hostname of chdlag01.int.dataline.ch.

This is configured by using CHGTCPDMN command:

• HOSTNAME should be the same as SYSNAME, just in lower case.
• DMNNAME should be your internal domain suffix.
• HOSTSCHPTY should be set *LOCAL, this avoids some delays.
• INTNETADR should be set to two of your companies internal DNS servers, NOT your ISPs DNS servers.

You will now need to add an appropriate hosts table entry using the ADDTCPHTE command. This is pretty self-explanatory.

Using GO TCPADM, 2 we can configure all our applications. My recommendation is to disable any application you don’t need RIGHT NOW. You can always reenable them later. I usually disable everything except Telnet and FTP, and enable SNTP (which is normally disabled). SNTP allows your i5/OS instance to sync against NTP timeservers. If you’re using Active Directoy, it’s a good idea to sync against the domain controller which inhabits the PDC FSMO role.

The last step would be to setup the Electronic Service Agent. I’ve documented this procedure in details earlier.