Compability of running Fortran/C++ generated exe's on earlier RedHat versions

[Tony_Garratt]

Is there any information on compability of executables generated by the Intel C++/Fortran compilers within a version of RedHat please? Suppose I compile using RedHat 4.8 and try running the executables on 4.1 say: should I expect them to run fine with no compatibility issues? What about version 2 or 3 of RedHat? Any help or pointers would be most appreciated! Thank you!

[TimP]

Intel compilers are no different from gnu compilers in this respect. The glibc version check will stop you if you link against dynamic libraries, and the installed version doesn't at least match what you built against. You must build with the oldest version you intend to support fully.
Red Hat may or not have made such a change in glibc between RHEL 4.1 and 4.8; such differences definitely exist between RHEL 3.x and 4.1. I doubt you would want to support anything prior to 4.3 or so. CentOS is readily available for those who can't afford the price of Red Hat upgrades.

[Tony_Garratt]

Quoting - tim18

Intel compilers are no different from gnu compilers in this respect. The glibc version check will stop you if you link against dynamic libraries, and the installed version doesn't at least match what you built against. You must build with the oldest version you intend to support fully.
Red Hat may or not have made such a change in glibc between RHEL 4.1 and 4.8; such differences definitely exist between RHEL 3.x and 4.1. I doubt you would want to support anything prior to 4.3 or so. CentOS is readily available for those who can't afford the price of Red Hat upgrades.

Thank you Tim - thats very helpful. I am somewhat of a novice when it comes to Linux and much more familiar with Windows. Our company develops simulation software for both Windows, Linux and AIX platforms. The compability issues with Linux is much more complex than with Windows, as your reply about glibc suggests. Up to now we have had a lot of problems with our Linux platform products, and have found we have had to ask our customers to install older glibc libraries etc on newer RHE versions to get our productsto work. This is a support burden and far from an elegant solution for our customers.

So I find myself asking the questions: "How do Isupport multiple RHE versions, say, 4 and 5. Do I do build on both versions and have two installers [a maintainence overhead] or do I just build on 4 and have my 5 installers put older versions of glibc etc in the 5 runtime path?" and "Should I build on the lowest version of each, i.e.4.0 to be sure I can support 4.x"?

But this compatibility issue of Linux is a general one when it comes to supporting products that are built with C++/Fortran and other vendors must have a solution, so rather than re-invent the wheel, I wonder if you have any pointers to forums or web pages or communities that might help with this issue.

Thank you so much! I realise this is not an Intel specific question and more of a Linux question.
Tony

[TimP]

I've been told Red Hat has a policy to test forward compatibility. For example, if you built on 4.3 it should run on a 5.4 installation. I think you would have to spot check this for your own application.
There are a number of issues with building with Intel compilers on older installations, even within the range which the compiler docs say are supported. For example, I don't think -xSSE4.2 can be expected to work on RHEL 4.3, unless you update binutils. Updating binutils would not have any effects which the customer would see when running a build which you have linked.
Observance of the glibc major version limitations is the most important question.