An update to the Red Hat Enterprise Linux 6.2 kernel after the 2.6.32-131.17.1.el6 version introduced a bug that causes Rational Performance Tester to stop with an Out of Memory error when you attempt to run tests or schedules. This issue was first observed in the 2.6.32-220.el6 kernel and is present on both x86_64 and i686 systems. This Flash describes how to revert to the earlier kernel without the bug, and provides the Red Hat bug ID number for reference.
Red Hat released the 2.6.32-131.17.1.el6 version of the Red Hat Enterprise Linux 6 kernel in November 2011. Rational Performance Tester 8.2.1 was successfully tested on both 64-bit and 32-bit installations of the Server product. The 2.6.32-220.el6 kernel was released in January 2012. The newer kernel has a bug that causes the out of memory error in Rational Performance Tester.
The out of memory error did not occur in the 2.6.32-131.17.1.el6 version of the kernel, but the error does occur in what seems to be the next higher version that RHEL has released.
The Red Hat bug ID for this is 770023.
Type the command uname -r (or uname -a) to display the version of the kernel that is running:
$ uname -r
This version of the kernel is where the bug was introduced.
By default, Red Hat Enterprise Linux saves the last two or three kernels when you update. To roll back to a version of the kernel that works with Rational Performance Tester, take the following steps:
Edit the grub.conf file with a text editor. Vi and gedit are typically available on Red Hat Enterprise Linux 6.
# vi /boot/grub/grub.conf
# gedit /boot/grub/grub.conf
Look for a section of the file similar to the following lines:
title Red Hat Enterprise Linux Server (2.6.32-220.el6.x86_64)
kernel /vmlinuz-2.6.32-220.el6.x86_64 ro root=/dev/mapper/vg_aernhartlin2-root rd_LVM_LV=vg_aernhartlin2/root rd_LVM_LV=vg_aernhartlin2/swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=auto rhgb quiet
title Red Hat Enterprise Linux Server (2.6.32-131.17.1.el6.x86_64)
kernel /vmlinuz-2.6.32-131.17.1.el6.x86_64 ro root=/dev/mapper/vg_aernhartlin2-root rd_LVM_LV=vg_aernhartlin2/root rd_LVM_LV=vg_aernhartlin2/swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=auto rhgb quiet
The title lines each indicate the start of a section that specifies a kernel level to boot into. Each section contains a few lines of additional information. This list of titles starts with an unseen index counter of zero. Thus, the first title is 0, the second is 1 and so on.
configures the system to boot into the kernel in the 0th (first) position in the list. In this case it is the 2.6.32-220.el6.x86_64 version. This kernel version has the bug that stops Rational Performance Tester. The -131 version listed in the second entry does NOT have the bug. To boot into this earlier version of the kernel, change the index number on the default line:
Save the grub.conf file, shut down any applications, and then reboot. The system should boot in the -131 kernel and Rational Performance Tester should run normally.
If your system does not have the entries for earlier kernels in grub.conf, you may able to revert to the earlier kernel by issuing this command:
# yum downgrade kernel