Differences in RHEL5.3 kernel versions

[John Donovan]

I have RHEL5.3 servers with kernel version 2.6.18-128.el5PAE. Just built a new server with kernel version 2.6.18-128.2.1.el5PAE.
The applications team is moving their healthcare product from RHEL3.4 servers to these RHEL5.3 servers. They are having problems.
Now they have noticed the different kernel version on the newest server and claim this is complicating their installs.
I've never heard of minor differences in the kernel having such an impact on application installs.
Of course, I'm rebuilding that latest server so the kernel version will match the others. But, in the future, we will upgrade the servers, (dev first, burn in for few weeks and then the test and prod servers).
So, is it realistic that even the minor changes in the kernel provided by RedHat should "break" applications?

Thanks,
:-)

[Steven E. Protter]

Shalom,

I almost never agree with app install people.

But.

The healthcare product may not be certified with the new kernel version.

I've often seen applications where if you try and install it on an kernel that is not certified, the installation will fail.

The jump from Red Hat 3 update 4 to Red Hat 5 update 3 is HUGE.

So the concerns are valid.

SEP

[John Donovan]

Hi, Steven...

I certainly agree that the move from RHEL3 to RHEL5 is significant and problems should be expected.

So, after the app is running on RHEL5.3, kernel 2.6.18-128.el5PAE... Should the app care if we bump the kernel to 2.6.18-128.2.1.el5PAE?

My thinking is that the newer RH kernel is backwards compatible. Is that not correct?

Thanks again...
:-)

[Steven E. Protter · Accepted solution]

Shalom,

Once the Application is running on RHEL 5, update 3 a switch to the latest kernel should not make a difference.

But this varies.

Oracle's OCFS2 filesystem product is tightly integrated with the kernel and will not run without new binaries on a new kernel.

It depends on the vendor. If they have special hooks into the kernel like clearcase and its mvfs file system, you can have problems.

It is best to check with the application vendor on this.

SEP

[kheller2]

Is their complaint that it is causing problems running or installing? Installing might be an issue as installers sometimes check for certain versions of the OS. My guess is they are trying to install the same package the installed on RH3 which probably has no idea what RH5 is. They should attempt to get an updated product. If not, then typically you would have to hack the installation a bit.

After that you typically run into problems where the libs are newer or not all the needed rpms have been installed as they were on RH3.

[John Donovan]

Thanks, Stephen and kheller2...

You have been quite helpful. Although there is no real solution, just confirmation that most applications are not sensitive to minor kernel updates or security patches. This one is.

Thanks, again...
:-)

[Gerardo Arceri]

Another Oracle product requiring updates after kernel version upgrades is ASM, you need to download the updated oracleasm packages matching the kernel version you are upgrading to.