There are a lot of organisations out there that are still running AIX 5.3. As you must know, AIX 5.3 is out of support. That doesn't stop you updating to the latest Technology Level (TL 12). But you may not be entitled to the latest Service Pack (SP 6). If you're staying with AIX 5.3, then you have a choice of being supported; unsupported (but legal), or unsupported and illegal!
Before looking at your Service Pack options for AIX 5.3, let's unravel what an AIX level really means.
AIX Levels Terminology
First, some bassic terminology:
TL = Technology Level
SP = Service Pack (bug fixes) for a TL
When you run the oslevel -s command, you get to see output such as:
Let's break that down:
- 5300 the AIX major release (e.g. 5300 = AIX 5.3, 6100 is AIX 6.1 and 7100 for AIX 7.1)
- 12 Technology Level (2 digits)
and then the
- 06-1216 Service Pack for that TL (first two digits are the service pack number. The next 4 digits show the year and week of the year that the SP was released in the format YYWW.)
So 5300-12-06-1216 means AIX 5.3, TL 12 SP 6 which was released in week 16 of 2012.
For more of a breakdown of the oslevel command, see my article Understanding AIX Versions.
Back to the Updates
When you connect to IBM Fix Central, you can step through the options to download the AIX updates: in other words, the Technology Level and / or Service Pack you want to update to. If you are staying on AIX 5.3, you get to choose from a range of Service Packs and Technology Levels. Here's what the latest Service Pack for TL 12 looks like:
Notice the key to the left of the "Service pack:" field. And did you see the line that reads Restrictions: entitled? What this means is that you are only eligible to download and install this Service Pack if you have purchased the Extended Support for AIX 5.3.
If you download and install this service pack (SP 6), and you don't have Extended support for AIX 5.3, you are not only unsupported. You are also running an illegal copy of AIX.
Now if you don't have extended support for AIX 5.3, you are entitled to download and install the second most recent Service Pack, which is AIX 5.3 TL 12 SP 5. Here's what that option looks like on IBM Fix Central:
Notice there is no Key alongside the Service pack name. And did you see when that SP was released? Week 40 of 2011. If you download and install this service pack, and you don't have Extended support for AIX 5.3, you are unsupported but not illegal.
Time to migrate to 7.1
So what do you do? In my view, migrate directly from AIX 5.3 to 7.1. Some people may think that is a brave jump, but if you are running on unsupported OS (AIX 5.3 without the Extended support option), with the risk of having to do an emergency, unplanned upgrade (without support), I would say you're the brave one.
You do have some other options other than migrating to AIX 7.1 (or at least 6.1). You could purchase the extended support for your existing AIX 5.3 servers. Or you could install an AIX 7.1 logical partition (LPAR) and then run an AIX 5.3 versioned WPAR within it. To do that, you still need to update your existing AIX 5.3 to TL 12. It all really depends on the life expectancy of your system and application. AIX 7.1 is fully binary compatible with versions 5 and 6 of AIX. If you're using Power7 (or plamning to), then your applications are supported, you have a binary compatibility guarantee for applications that run AIX 5.3, 6.1 or 7 on Power4 or later.
In short, the upgrade to AIX 7.1 is, in my view, your best option. The migration process is relatively easy. You don't need to jump to AIX 6.1 first. There are a wealth of functional and performance benefits, and you have the prospect of moving to a supported environment. If you're still on AIX 5.3 and you're not purchasing extended support or moving up to a more recent AIX level, then you are choosing to stay on a stable but unsupported OS. For many businesses, that would be an unacceptable exposure.