Jim Hannan (@HoBHannan), Principal Architect

Oracle Ksplice (also referred to as uptrack or Ksplice uptrack)

http://www.ksplice.com is a kernel patching tool for Linux that does not require a reboot after applying a patch.

“On July 21, 2011, Oracle announced that it has acquired Ksplice, a privately-held company based in Cambridge, MA. Ksplice is the creator of innovative zero downtime update technology for Linux.”

To date, this tool is the first of its kind for Linux. Ksplice allows for Linux administrators to patch the Linux kernel without taking an outage or shutting down any applications — like Oracle RDBMS.

For business critical applications, like Oracle databases, this is a really compelling feature.

Oracle Ksplice offers the following:

• No downtime
• No disruption (applications like Oracle are unaffected)
• No rebooting
• Potentially better security (In today’s industry, security patching is a must. Often the Linux kernel has security updates — Ksplice allows you apply the updates without an outage.)

Now, to be fair, I have not been a big proponent of Oracle Enterprise Linux over Red Hat and Suse Linux. There are primarily two reasons for this, one is because of hardware support — most hardware vendors do not officially support Oracle Enterprise Linux. This does not mean that most hardware vendors will not help you if you call with an issue. However, it does mean that if you have driver issues running in OEL (Oracle Enterprise Linux) the vendor will most likely not help you. The other reason I have not advocated for OEL in the past is because of VMware support. Until September 2012, VMware did not offer support for OEL and UEK and a supported guest OS. With this VMware announcement about Oracle Linux support and UEK support it is now supported in vSphere 5.1.

How to get Ksplice

Ksplice is offered free of charge with the purchase of Oracle Premier Support for OEL. Ksplice can also be purchased for Red Hat Linux, but you will need Oracle Premier Support. You will also need to use Oracle’s software repositories instead of Red Hat’s.

How Ksplice Works

Ksplice is a kernel-patching tool only. This means you need to continue using yum to update your RPMS.

Oracle releases a Ksplice patch by using the following workflow:

Kernel update released -> Ksplice technology (Oracle using Ksplice technology takes the patch and creates a Ksplice patch) -> Customers can download and apply Ksplice kernel patch.

As I mentioned before, the tool is often referred to as uptrack. That is because of the command line wrapper script names (see below). The tool also has web interface, which I am only familiar with by demo. The interface offers a portal of all the Linux nodes checked in under your Ksplice key.

What about VMware Tools after running Ksplice uptrack? Will I need to re-run vmware-config.pl?

No, Ksplice updates do not change the kernel ABI (Application Binary Interface) or system libraries. The updates are transparent to both running applications like Oracle and third-party kernel modules like VMware Tools.

There you have it, a great feature for customers with tight SLAs. I also applaud VMware for supporting OEL. This to me reiterates VMware’s commitment to their Oracle customers running on VMware. In my opinion, the best platform to run OEL is in VMware vSphere.

¹ Oracle recommends running this command over uname –a because the running Linux OS may become unaware a hot patch has been applied.