Wednesday Jul 31, 2013

Using Ksplice for diagnostic purposes

laptop and stethoscope by jfcherry, on Flickr
laptop and stethoscope by jfcherry (CC BY-SA 2.0)

We've been emphasizing the benefits of using Oracle Linux with Ksplice rebootless updates several times already. The ability to minimize downtime when applying rebootless patches to the Linux Kernel is a feature unique to Oracle Linux, and a growing number of customers realize the benefits of this technology.

Since we acquired Ksplice two years ago, we've continued to improve and further integrate this functionality in Oracle Linux. For example, we implemented the the Ksplice offline client (which I mentioned in this YouTube whiteboard session some time ago), the Ksplice Inspector, or the RedPatch utility.

But did you know that we use Ksplice for diagnostic purposes, too? As part of our Oracle Linux Premier Support offering, we can make use Ksplice to enable additional debugging functionality on your production system, if we need to track down an issue in your environment. Instead of asking you to reboot into a custom Linux kernel that contains additional debugging code, we now simply create a custom Ksplice patch that helps us to gather the required information, while your system keeps running. Once we've obtained the necessary details, you can simply remove the debug patch with Ksplice at runtime again, without any interruption. The additional debugging information helps our support team to determine the root cause of your issue. In case it turns out to be a genuine bug in the Linux kernel, we will then develop and provide a bug fix for this particular problem in the form of a new Ksplice patch, which you can apply while the system keeps humming along. Bug analyzed and fixed, no reboot was required!

To learn more about his feature and the other advantages of Ksplice, take a look at Wim's recent blog post "The Ksplice differentiator".

Monday Jul 15, 2013

Migrating from SUSE Linux to Oracle Linux - System Initialization

The iptables service defines rules for handling packets on a Linux system. It's usually a good idea to disable this service during installation of a Linux update to prevent malicious code from being installed by angry cats (image removed from blog). Once the update is installed securely, you can define the iptables rules and once again enable the service.

To find out, before you install an update to Oracle Linux, whether the iptables service is enabled, use the list option to the chkconfig command. It displays the status of Linux services at boot time. For example:

# chkconfig -- list
abrtd 0:off 1:off 2:off 3:on 4:off 5:on 6:off
acpid 0:off 1:off 2:off 3:off 4:off 5:off 6:off
atd 0:off 1:off 2:off 3:on 4:on 5:on 6:off
...
...
iptables 0:off 1:off 2:off 3:off 4:off 5:off 6:off
...
...
SUSE Linux to Oracle Linux: Guide for System Administrators
17
...
...

To check the status of only the iptables service, pipe in a little grep:

chkconfig -- list | grep iptables

This is just one of the tips provided by Manik Ahuja and Kamal Dodeja in their OTN technical article, ....

Tech Article: How to Initialize an Oracle Linux System

This is the first in a series of articles that outline the major steps in migrating from SUSE Linux to Oracle Linux. It focuses on registering your system, downloading the latest version of Oracle Linux, and performing some basic initialization steps. Stay tuned for more articles.

Tech Article: How to Initialize an Oracle Linux System

- Rick

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