"Enterprise edition" means you can define and run LPARs with more than 4 cores and more than 32GB of memory. In daily business the difference between standard and enterprise (AFAIK "express" discontinued, but not sure about this) is NIL.
You can, using the chedition command, even change it.
When you upgrade from 6.1 (which is suggested, even if you have bought extended support, which might bring you up to Apr 2020) you may want to check the LPAR profile if your 6.1-partition runs in compatibility mode. If so, reset that before you boot into the 7.x installation.
Personally, i'd rather recommend using AIX 7.1.5 TL 5 instead of 7.2 TL2(or TL3? not sure). 7.2 is a major overhaul and - like all big changes - has a lot of problems. I#D suggest using the much less bug-ridden 7.1, which will be supported until 2021 at least and go to a (right now hypothetical) 7.3 once it is there. It was, btw., the same with version 5: 5.1 was quite OK, 5.2 (and 5.2.1 as well) was buggy as hell, 5.3 was stable from the start and got better with every TL. In the end 5.3 ran all the way up to TL13 for about 10 years.
TL = technical level
You have versions and releases and i suppose you know about these. Below this are "technical levels", which (very roughly) correspond to what is known as a "service pack" in WIndows: a lot of bugfixes and minor corrections made over time bundled into a "mini-release". Back then these have been called "maintenance levels" ("ML"), which was basically the same, but IBM is in the habit of renaming anything every few years.
Get the current TL by issuing (as root):
instfix -i | grep AIX_TL
Note, that the oslevel command only shows the latest completely installed TL. If you have parts of a newer TL installed it will show in the instfix command, but not in oslevel . See the pinned thread in the AIX forum for details.
PowerHA = SystemMirror = HACMP
Seaking about renaming things: this is the cluster software for AIX and - see above - known under quite a few names. All these names describe exactly the same product, just renamed. The AIX cluster is a very reliable, very stable, very versatile piece of software, but rather costly. Still, i would rely for mission-critical systems on nothing else, it is money well invested. If done and maintained correctly we are talking about the type of systems where one outage every ten years is considered shoddy work.
PowerVM = the IBM hypervisor
This is the IBM hypervisor and basis of IBMs virtualisation. It is way faster than anything else in the market and with unparalleled data throughput, but it supports Linux only as LPAR. You can use PowerKVM (the KVM implementation on Power) instead, but then only Linux containers/LPARs are supported and it is slower than PowerVM. Basically PowerVM is (built into the hardware and used by) the VIOS, the HMC and their workings.
See above, not quite, although VIOS is a part of it.
So, if I would to go with HACMP, I have to download this version. It's not possible to install it from scratch on the fresh new AIX(If I install my AIX before with standard/ TL version)
PowerVM is "POWER Virtual Machines" and the VIOS is an important component. The POWER firmware is also a component, and back in POWER5 times, there was a component that emulated Intel x286 instructions - on the fly.
AIX TL support - AIX Technology Level Support, more frequently TL-SP - Technology Level Service Pack
PowerHA - POWER High Availability - also know as HACMP (High Availability Cluster Management Protocol), or as SystemMirror.
As to upgrade - I agree that staying with AIX 7.1 is better than a leap to AIX 7.2 - there are also a lot of packaging changes that just make it 'different' from what is was for decennia.
M-a-n-y t-h-a-n-k-s !! This is what i was what i just tried to tell some, ahem, colleagues (for lack of a more fitting term) after sitting through them showing us some copied marketing material (you probably know the type: "live update ability: AIX 7.1 no, AIX 7.2 yes", etc.. We don't even have LPM and we don't know what this "live update" is anyway, but we want the product with more bullets in the bullet list.) I am glad to see this my personal impression confirmed by someone else.
My personal impression (based only on my own experience) is that 7.2 is going to be similar to 5.2 (and 4.2.x before that): they changed many things in AIX back then and they are changing a lot of things now, It takes time for these new feature to mature and this is why i shy away from all the 7.2 TLs and use 7.1.x instead for now. I suppose once they bring AIX 7.3 (or however it will be named, maybe AIX 8) it will perhaps be with all these features and stable too.
