Month: August 2015

Identifying excessive load causes with oracle enterprise manager 11g


There are times when people ask me to identify the root causes of excessive Oracle Database (and host) loads in the past, still being astonished how i do manage to get this information out of nothing. Well, really, there is no out of nothing, never. There may be a complex scenario and a couple of tools at hand which span another level of complexity, unfortunately. That’s all of it. You see, complexity is a bad thing, something you will want to avoid or eliminate at all times. Some people furthermore aim to prove their skills in talking about what degree of complexity they are able to handle… hhm, poor ones, I don’t envy them, always struggling to tighten a plethora of strings, over and over, I’m more a convention-over-configuration guy, but that’s another discussion.

Back to to the point, Oracle Database is a vast stack of technology, indeed inducing a fair level of complexity in analysis and so is Oracle Enterprise Manager, the number one monitoring tool for the database and further (so called) targets like hosts and jvms, in operation. In fact, Oracle Enterprise Manager, being based on data collection in the database (AWR – Automatic Workload Repository), data evaluation in the database (ADDM – Automatic Database Diagnostic Monitor) and data transfer to some production instance (Enterprise Manager Agent) constitutes another mountain top in the Oracle landscape not everyone is able or willing to climb. So iff you misplaced your hiking boots for today, the following is for you.

Ok then, log yourself in, using your EM credentials.

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Locating kernel headers for vmware tools on an uekr3 oracle linux 6.7


Continuing, if you like, on an admin topic concerning UEKR3 Oracle Linux 6.5, see: Missing kernel-firmware 3.8.13-16.2.1.el6uek on Oracle Linux 6.5, I’ going to give a recipe and some explanations for getting vmtools modules successfully built in a VMware guest after complains about an invalid kernel header path.
Immediately after installing vmtools in a VMware guest, usually using /vmware-tools-distrib/vmware-install.pl, another script, usually /vmware-tools-distrib/bin/vmware-config-tools.pl comes up, asking whether you want to configure vmtools just now. Configuration essentially comprises the opt-in/out of functionality as well as building and integration of kernel modules into the running kernel. Iff you furthermore run a recent UEKR3 kernel without the according development packages, the console output may read like this:

...
Before you can compile modules, you need to have the following installed... 
make
gcc
kernel headers of the running kernel

Search in repoquery --list kernel-uek-devel-3.8.13-68.3.5.el6uek.x86_64 for GCC...
Detected GCC binary at "/usr/bin/gcc".
The path "/usr/bin/gcc" appears to be a valid path to the gcc binary.
Would you like to change it? [no] 

Searching for a valid kernel header path...
The path "" is not a valid path to the 3.8.13-68.3.5.el6uek.x86_64 kernel headers.
Would you like to change it? [yes] y

Enter the path to the kernel header files for the 3.8.13-68.3.5.el6uek.x86_64 kernel
/usr/include/linux

The path "/usr/include/linux" is not a valid path to the 3.8.13-68.3.5.el6uek.x86_64 kernel headers.
Would you like to change it? [yes] n

WARNING: This program cannot compile any modules for the following reason(s)...

- This program could not find a valid path to the kernel headers of the running
kernel.  Please ensure that the header files for the running kernel are 
installed on this sytem.

[ Press Enter key to continue ] 

What actually happens here is quite simple but however also expressed in a misleading way such that she/he may just suppose, installing the kernel headers will fix the problem (I even tried this /usr/include/linux thing, as of the old days, won’t work you see, is none of uekr3 anyway).

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