Recompiling executables results in "undefined reference to `__pure_virtual' "

In a recent upgrade from 11.5.9 to 11.5.10.2, on Red Hat Enterprise Linux 4, I ran into a problem where certain executables were not compiling. As it turned out, the executables (ENCACN, WICDOL, WICMEX, WICMLX) were all compiled with g++.

This was our 3rd iteration of the upgrade and this behavior had not been observed in prior upgrades. The difference between interation #2 and iteration #3 was that the operating system level had been upgraded to update 5. This resulted in me starting from a clean slate and going through all the prerequisites to make sure something was not missed.

The most obvious place to me was to look at the environment variable LD_ASSUME_KERNEL. A quick check on the command line indicated that it was already set and this was not my problem. On a side note, this variable is set by the script $AD_TOP/bin/adgetlnxver.sh which is called by $APPL_TOP/$CONTEXT_NAME.env which in turn is then called by $APPL_TOP/APPS$CONTEXT_NAME.env.

oradev@app-dev01> echo $LD_ASSUME_KERNEL
2.4.19

Next, I checked the version of gcc and g++ to make sure those executables were pointing at the corrected versions.

Using the command gcc -v and g++ -v should yield the following results:
gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-47.3)

The obvious prerequisite RPMs were there:
compat-db-4.1.25-9
compat-gcc-32-3.2.3-47.3
compat-gcc-32-c++-3.2.3-47.3
compat-libgcc-296-2.96-132.7.2
compat-libstdc++-296-2.96-132.7.2
compat-libstdc++-33-3.2.3-47.3
xorg-x11-deprecated-libs-devel-6.8.1-23.EL
xorg-x11-deprecated-libs-6.8.1-23.EL
openmotif-2.1.30-x

We also had the two following RPMs installed deliverd via Oracle patch 4198954 (COMPATIBILITY PACKAGES FOR ORACLE ON RHEL 4):
compat-oracle-rhel4-1.0-5
compat-libcwait-2.0-2

Unfortunately this particular situation was not publicly documented on MetaLink. There were other hits on __pure_virtual and ENCACN, but none of them were applicable. The solution was to uninstall patch 4198954 and then reinstall it. This is supposed to be documented in MetaLink Doc ID: 435078.1 "Relink errors with ENCACN on Red Hat 4.0", but at the time of this post was not an externally viewable document. This resulted in performing the following steps below as the user root.

Remove the following packages:
rpm -ev compat-oracle-rhel4 rpm -ev compat-libcwait

Reinstall the following packages:
rpm -ivh compat-libcwait-2.1-1.i386.rpm
rpm -ivh compat-oracle-rhel4-1.0-5.i386.rpm

Once the packages were reinstalled, we were then able to successfully compile ENCACN using the following command:
adrelink.sh force=y "eng ENCACN"

I then went into adadmin and recompiled all the executables to ensure nothing else broke as a result of this. The typical caveats apply. Do this in a test environment first and shutdown the application before recompiling the executables.

Brian Bent | Solution Architect | Solution Beacon

Fun with Linux Filesystem Labels

Most things in life involve a little Give and Take, and filesystems in Linux are certainly no exception.

On the Give side of the equation Linux offers the ability to identify a filesystem not only by its traditional device file name, such as /dev/sde1, but also by a unique label that you can apply to the filesystem.

On the Take side, if you've ever supported a Linux system attached to SAN storage you know that a simple act such as adding or removing a LUN can cause Linux to remap your /dev/sd entries, causing what used to be /dev/sde1 to become /dev/sdd1.

The problem is readily apparent when you reboot the server. Your server is no longer able to locate the /dev/sde1 device in order to mount it at /oracle!

This problem can be solved by using filesystem labels, which are entries in the header structure of an EXT3 filesystem. By using the following command (logged in as root of course)

tune2fs -L oracle /dev/sde1

you can set the label for the filesystem "/dev/sde1" to the keyword "oracle".

While labels allow the use of some special characters like / and _ in their names, I recommend keeping the label simple and indicative of where the fileystem belongs.

To see the results of your change, use

tune2fs -l /dev/sde1   (note the lowercase "L")

Then to make this change effective alter the /etc/fstab entry for /oracle and replace the device file with a special label keyword as shown here:

LABEL=oracle /oracle ext3 noatime 1 1

This approach works for the native Linux EXT3 filesystem as well as for Oracle's OCFS and OCFS2 filesystems.