Oracle Linux support in ESXi

For quite some time now I am using ESXi 5 update 1 for my lab server and I’m very happy with it. In my lab environment I am not too picky what to run and do not worry about support too much. It’s not production!

One area of concern has been the support for Oracle’s own kernel: UEK or Unbreakable Enterprise Kernel. UEK comes in two editions, one based on 2.6.32, just like Red Hat’s kernel for Red Hat 6. The difference is that you can get UEK/1 ( for Oracle Linux 5.x as well instead of 2.6.18xxx which is otherwise the default.

Oracle’s second iteration of kernel UEK is unsurprisingly named UEK2 and it’s initially based on 3.x but keeps the name to 2.6.39.x for compatibility reasons. UEK2 has some really nice features taken from the Upstream kernel and it is also supported for the Oracle database.

Until not too long ago UEK was not supported by VMware ESXi, but this has changed without me taking notice at first. Thanks to a tweet by @dba_emc2 (Allan Robertson) I learned more about the change in the support policy. One interesting blog post from VMware is found here:

This post only mentions UEK, but does not clearly state whether UEK or UEK2 or both will be supported. The VMware Compatibility Guide has more information at

  • In the search, enter “unbreakable” to be directed the the relevant certification information
  • It turns out it is (at the time of this writing) UEK 2 actually which is great news for me!
  • Supported versions of ESXi are 5 u1, 5u2 and 5.1 at the time of writing
  • Support date is listed as 09/2012
  • There are even specific installation instruction but they don’t go over and above what you would normally do
  • What’s very interesting is that the paravirtualised drivers for SCSI (vSCSI) and VMXNet3 are supported too
  • You can also add virtual CPUs and memory while the VM is up (with the proper VM settings, I think hot-adding these is deactivated by default)

Enjoy! I will try to install Oracle Linux 6.3 – which is the first to my knowledge that boots UEK2 by default – next and install the VMware tools. Let’s see how that goes.


3 thoughts on “Oracle Linux support in ESXi

  1. Jay Weinshenker

    Note that you can’t use the prebuilt rpms for installing VMware Tools when using UEK or UEK(2). Also note that support is only for vSphere ESXi 5.1 (not 5.0). Still, it’s good to see.

    1. Martin Bach Post author

      Thanks Jay,

      I have added the update levels to make that clearer.


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