Hi all,

Question on TL/SP compatibility best practices for AIX 7.2/7.3.

We're building an on-prem security scanner for AIX. The core is Go, but we ship a C dependency (YARA) as part of it. We're trying to decide how to structure build/test environments to maximize compatibility across TL/SP levels.

 • If we build on an older TL/SP (baseline), is it generally safe to expect it to run on newer TL/SP within the same AIX major version?
 • Conversely, if we build on a newer TL/SP, how often do you see binaries fail on older TL/SP due to runtime/library differences?
 • Is "build on oldest supported TL/SP, test on oldest + current" the usual approach?

Example oslevel strings we currently see in IBM Cloud:
 • AIX 7.3: 7300-03-00-2446
 • AIX 7.2: 7200-05-11-2546

Any gotchas around linking (static vs dynamic) or common library mismatches would be helpful.

I think AIX binary compatibility will help you here - if you build on the oldest TL you support you should be fine on newer TL/SP levels, and IBM's docs explain this here: https://www.ibm.com/docs/en/aix/7.3.0?topic=aix-binary-compatibility and the restrictions here: https://www.ibm.com/docs/en/aix/7.3.0?topic=compatibility-restrictions-aix-binary.

Hi all,

Question on TL/SP compatibility best practices for AIX 7.2/7.3.

We're building an on-prem security scanner for AIX. The core is Go, but we ship a C dependency (YARA) as part of it. We're trying to decide how to structure build/test environments to maximize compatibility across TL/SP levels.

 • If we build on an older TL/SP (baseline), is it generally safe to expect it to run on newer TL/SP within the same AIX major version?
 • Conversely, if we build on a newer TL/SP, how often do you see binaries fail on older TL/SP due to runtime/library differences?
 • Is "build on oldest supported TL/SP, test on oldest + current" the usual approach?

Example oslevel strings we currently see in IBM Cloud:
 • AIX 7.3: 7300-03-00-2446
 • AIX 7.2: 7200-05-11-2546

Any gotchas around linking (static vs dynamic) or common library mismatches would be helpful.

Hi all,

Question on TL/SP compatibility best practices for AIX 7.2/7.3.

We're building an on-prem security scanner for AIX. The core is Go, but we ship a C dependency (YARA) as part of it. We're trying to decide how to structure build/test environments to maximize compatibility across TL/SP levels.

 • If we build on an older TL/SP (baseline), is it generally safe to expect it to run on newer TL/SP within the same AIX major version?
 • Conversely, if we build on a newer TL/SP, how often do you see binaries fail on older TL/SP due to runtime/library differences?
 • Is "build on oldest supported TL/SP, test on oldest + current" the usual approach?

Example oslevel strings we currently see in IBM Cloud:
 • AIX 7.3: 7300-03-00-2446
 • AIX 7.2: 7200-05-11-2546

Any gotchas around linking (static vs dynamic) or common library mismatches would be helpful.

>  • If we build on an older TL/SP (baseline), is it generally safe to expect it to run on newer TL/SP within the same AIX major version?

As Chris pointed - yes. I have binaries built on AIX 5.3 20 years ago, and they are still running on AIX 7.3 without any modifications. The main point here is to understand the restrictions. Another thing that might cause problems with compatibility is the compiler you use. If you use gcc, then you have libgcc as a dependency, and there are too many different versions of it. I had a program compiled with gcc 2.9.5 on AIX 4.3, I think. Somewhere at the end of the 90s. It worked without big problems on AIX 7.2 30 years later, but libgcc 2.9.5 had to be installed on the system. It didn't work with newer libgcc versions. My recommendation - use IBM's "classic" XL C/C++ compiler if you need compatibility with older AIX versions. If you plan to work only with the latest AIX 7.2 TL5 and AIX 7.3, then you can use the IBM OpenXL compiler, which is clang-based and more "Linux-compatible".

> Conversely, if we build on a newer TL/SP, how often do you see binaries fail on older TL/SP due to runtime/library differences?

It can happen and happened to me. I prefer to build on older versions.

>  • Is "build on oldest supported TL/SP, test on oldest + current" the usual approach?

Yes, or build on oldest possible TL/SP and test on the current, or what you must support.

Hi all,

Question on TL/SP compatibility best practices for AIX 7.2/7.3.

We're building an on-prem security scanner for AIX. The core is Go, but we ship a C dependency (YARA) as part of it. We're trying to decide how to structure build/test environments to maximize compatibility across TL/SP levels.

 • If we build on an older TL/SP (baseline), is it generally safe to expect it to run on newer TL/SP within the same AIX major version?
 • Conversely, if we build on a newer TL/SP, how often do you see binaries fail on older TL/SP due to runtime/library differences?
 • Is "build on oldest supported TL/SP, test on oldest + current" the usual approach?

Example oslevel strings we currently see in IBM Cloud:
 • AIX 7.3: 7300-03-00-2446
 • AIX 7.2: 7200-05-11-2546

Any gotchas around linking (static vs dynamic) or common library mismatches would be helpful.

Hi all,

Question on TL/SP compatibility best practices for AIX 7.2/7.3.

We're building an on-prem security scanner for AIX. The core is Go, but we ship a C dependency (YARA) as part of it. We're trying to decide how to structure build/test environments to maximize compatibility across TL/SP levels.

 • If we build on an older TL/SP (baseline), is it generally safe to expect it to run on newer TL/SP within the same AIX major version?
 • Conversely, if we build on a newer TL/SP, how often do you see binaries fail on older TL/SP due to runtime/library differences?
 • Is "build on oldest supported TL/SP, test on oldest + current" the usual approach?

Example oslevel strings we currently see in IBM Cloud:
 • AIX 7.3: 7300-03-00-2446
 • AIX 7.2: 7200-05-11-2546

Any gotchas around linking (static vs dynamic) or common library mismatches would be helpful.

Hi all,

Question on TL/SP compatibility best practices for AIX 7.2/7.3.

We're building an on-prem security scanner for AIX. The core is Go, but we ship a C dependency (YARA) as part of it. We're trying to decide how to structure build/test environments to maximize compatibility across TL/SP levels.

 • If we build on an older TL/SP (baseline), is it generally safe to expect it to run on newer TL/SP within the same AIX major version?
 • Conversely, if we build on a newer TL/SP, how often do you see binaries fail on older TL/SP due to runtime/library differences?
 • Is "build on oldest supported TL/SP, test on oldest + current" the usual approach?

Example oslevel strings we currently see in IBM Cloud:
 • AIX 7.3: 7300-03-00-2446
 • AIX 7.2: 7200-05-11-2546

Any gotchas around linking (static vs dynamic) or common library mismatches would be helpful.

Hi all,

Question on TL/SP compatibility best practices for AIX 7.2/7.3.

We're building an on-prem security scanner for AIX. The core is Go, but we ship a C dependency (YARA) as part of it. We're trying to decide how to structure build/test environments to maximize compatibility across TL/SP levels.

 • If we build on an older TL/SP (baseline), is it generally safe to expect it to run on newer TL/SP within the same AIX major version?
 • Conversely, if we build on a newer TL/SP, how often do you see binaries fail on older TL/SP due to runtime/library differences?
 • Is "build on oldest supported TL/SP, test on oldest + current" the usual approach?

Example oslevel strings we currently see in IBM Cloud:
 • AIX 7.3: 7300-03-00-2446
 • AIX 7.2: 7200-05-11-2546

Any gotchas around linking (static vs dynamic) or common library mismatches would be helpful.

From my nmon and njmon experience, I would just compile to the latest AIX 7.3 TL and sp or one version back if you don't want to upgrade every time.

 - Of course, avoid any new functions and features, such as those delivered in a recent TL.

 - A decade ago, the libperfstat library was improved for every TL = a nightmare, if you wanted the newer stats. But now it has been stable for many years, so a single binary covers AIX 7.1, 7.2, and 7.3.

 - For the VIOS, I have to create a different binary as the VIOS has extra virtual resource functions. If I include these, the program does not run on "pure" AIX because it detects missing VIOS functions at startup.

Then run a quick test on older AIX releases. If there is a problem, your program will probably fail to start at all due to library mismatches. If it starts up, it will probably work fine.

For njmon The AIX 7.3 binary runs fine on AIX 7.2.

Users will prefer one binary that works on AIX 7.2 and AIX 7.3 - so only have two binaries, if you are forced to.

No need to have a security scanner program for AIX 7.1 or older.

 - If the user is running these releases, then they do not care about security at all! :-)

I compile with the latest GCC compiler from the open source toolbox - it saves all that mucking around with licenses.

If you need extreme performance, then the more advanced compilers might help or might not.

I hope this helps, N

Hi all,

Question on TL/SP compatibility best practices for AIX 7.2/7.3.

We're building an on-prem security scanner for AIX. The core is Go, but we ship a C dependency (YARA) as part of it. We're trying to decide how to structure build/test environments to maximize compatibility across TL/SP levels.

 • If we build on an older TL/SP (baseline), is it generally safe to expect it to run on newer TL/SP within the same AIX major version?
 • Conversely, if we build on a newer TL/SP, how often do you see binaries fail on older TL/SP due to runtime/library differences?
 • Is "build on oldest supported TL/SP, test on oldest + current" the usual approach?

Example oslevel strings we currently see in IBM Cloud:
 • AIX 7.3: 7300-03-00-2446
 • AIX 7.2: 7200-05-11-2546

Any gotchas around linking (static vs dynamic) or common library mismatches would be helpful.