Edit: To be clear the lppsource and spot were from the new AIX level, you do not use a spot from the mksysb in order to get this method to work. And it still works great with 7.1 and 7.2 if you need to have a more recent version of AIX to get it to run on POWER9.
Originally posted May 26, 2020 on AIXchange
The system software map comes in handy when a customer that was running AIX 6.1 on a POWER5 server wanted to migrate their LPAR to POWER9.
Recently a customer that was running AIX 6.1 on a POWER5 server wanted to migrate their LPAR to POWER9*. They were running 6100-09-09-1717 and rather than perform an update on the source LPAR, they preferred to take a mksysb and simply run it on their POWER9 system.
They consulted the system software map to learn the minimum levels needed to run AIX 6.1 on POWER9:
Technology Level: 6100-09
Base Level: 6100-09-11
Recommended Level: 6100-09-12-1846
Latest Level: 6100-09-12-1846
So how could we take their mksysb from 6100-09-09-1717 to the recommended/latest level? I reached out to IBMer Chris Gibson, who said they could migrate their mksysb on the fly.
You can restore directly the mksysb to the latest TL, if you have a nim server use the command below:
nim -o bos_inst -a source=mksysb -a lpp_source=<lpp_source> -a spot=<SPOT> -a mksysb=<mksysb> -a image_data= mksysb_image_data -a accept_licenses=yes client_hostname
My customer wisely has extended support from IBM for AIX 6.1. This provides access to download media from Entitled Systems Support (ESS).
The last level available for AIX 6.1 base media was 6100-09-12-1837, so they downloaded that and made it available on their NIM server as the lppsource and the spot. Then they ran the command, which restored and then updated their mksysb on the fly. Once it booted up, we were able to download the latest fixes and update it to 6100-09-12-1846.
It’s quite a testament to AIX that an OS version that GAed in 2007 can run on the latest hardware—not to mention that the whole migration/updating process can be done on the fly.
You might not run into this sort of thing every day, but if you ever need to do something similar, hopefully you’ll recall this post.