Recently, my washing machine was stuck on a spin cycle. I stopped it, moved the dial and started up again (similar to rebooting!), and everything worked. But if it happens again, I have to decide whether it is worth fixing - it is over 40 years old! We've fixed it a couple of times over the years, but the last time, the repair person suggested buying a new one the next time something goes wrong. That day might be upon us!
With software, there tends to be two philosophies concerning updates; either upgrade to the latest all the time or don't upgrade until you have a problem.
Regarding the ITM System p agents, you should definitely update your systems to the latest interim fixes, since there are important fixes to problems you might not be aware of. The fixes tend to resolve core dumps or incorrect data, and the details are in the readme files. The interim fixes are available on the System p Agent Troubleshooting Wiki.
The one exception to this rule might be interim fix 1 for the HMC Base agent v126.96.36.199. Of course, applying this interim fix won't hurt, but there are only a couple of problems that might affect you:
1) If you have more than 70 LPARs per server, then you might not get data on the Tivoli Enterprise Portal. You will surely know if you have this problem (APAR IV47101).
2) A lesser important problem might occur on a large HMC, where you might not get data just on the Memory and Paging Space views of the System workspace (APAR IV50135). This workspace only provides memory and paging space data on the HMC itself.
Click here to see the details: 188.8.131.52-TIV-ITM_HMC_BASE-IF0001
This interim fix is only for the agent and does not affect the application support files, so you will not need to recycle your TEMS and TEPS. Plus, the HMC agent is a self-describing agent, so application support file installation is not the big deal it used to be.
And remember that the HMC Base agent replaces the CEC Base agent and the UNIX OS agent replaces the AIX Premium agent, so your focus should be on keeping your VIOS Premium and HMC Base agents up to date. And maybe I should bring my laundry room up to the 21st century!