The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

3.1 Overview of Oracle Ksplice

Linux systems receive regular security updates to core operating system components that necessitate patching and rebooting. Traditionally, applying such updates would require you to obtain and install the updated RPMs, schedule downtime, and reboot the server to the new package version, with any critical updates. However, as system setups become more complex, with many interdependencies, access to services and applications must remain as undisrupted as possible, as scheduling such reboots becomes more difficult and costly.

Oracle Ksplice provides a way for you to keep your systems secure and highly available by enabling you to update them with the latest kernel and key user-space security and bug fix updates, and Xen hypervisor updates on Oracle VM Server 3.4.5 and later.

Note

When using Ksplice to patch the Xen hypervisor on Oracle VM Server 3.4.5 and later, the minimum version that is required is xen-4.4.4-196.el6.x86_64.rpm.

Oracle Ksplice updates the running operating system without requiring a reboot. Your systems remains up to date with OS vulnerability patches and downtime is minimized. A Ksplice update takes effect immediately upon application. Note that a Ksplice update is not the same as an on-disk change that requires a subsequent reboot to take effect. However, note that on-disk updates are still required when using Ksplice to ensure that package binaries are updated to the most recent version and can be used in the event that the system or processes are restarted. On-disk updates are handled by subscribing to the Unbreakable Linux Network (ULN) or by using a local ULN mirror.

Oracle creates each Ksplice update from a package update that originates either from Oracle or the open source community.

To learn more about Ksplice, go to http://www.ksplice.com/.