Switching to PAE Enabled Kernel on Software Appliance

Versions 2.5, & 3.0

Applies to Platform: UTM 2.5, UTM 3.0
Last Updated on: 05th of April 2015

This article introduces you to the procedure needed in case you have to switch to the PAE enabled kernel, which is required if you provide over 4GB of RAM to your Endian UTM Appliance to recognize all the memory that is available to it. PAE stands for Physical Address Extension and allows 32-bit CPU to manage ranges of more than 4096 MB of RAM, i.e., 4GB.


On the 5.0 version all kernels are PAE-enabled by default.


The first task to carry out is to update the packages availability:

root@endian~#: efw-update update

Optionally, perform a system upgrade:

root@endian~#: efw-update upgrade

Finally, you may want to verify that the system recognises the whole memory, though it can not use all of them with a non-PAE kernel:

root@endian~#: free -m
                   total       used       free     shared    buffers     cached
Mem:          4014       1223       2790          0        373        565

Checking the Current Kernel

The first step is to make sure that your current kernel does not have Physical Address Extension enabled. The next command is used to verify the installed kernel, whose name should not contain "PAE", like below:

root@endian~#: uname -r

Switching to PAE Enabled Kernel

Once you know that you have to install the PAE kernel, follow with the next command, which installs both the kernel and all the modules necessary to its correct functioning. You should see an output similar to the one below: Confirm when prompted about the changes by pressing either the Y or the ENTER key:

root@endian~#: smart install kernel-PAE kernel-module-*-PAE
Loading cache...
Updating cache... ########################################### [100%]

Computing transaction...

Installing packages (6):

Removing packages (4):

12.9MB of package files are needed. 55.0kB will be used.

Confirm changes? (Y/n):

Notice that besides installing the packages with the new kernel, several other packages, containing the old kernel and its related modules, will be removed from the system. Once this task has been completed, you can check with the next command, which should be followed by an output similar to the one below, that no more non-PAE kernel packages are present, but only PAE-enabled ones:

root@endian~#: rpm -qa | grep kernel*

 Finally, It is always recommended to reboot your Endian UTM Appliance, if possible, to ensure that the new kernel is loaded and correctly functional with all of the settings applied. After the reboot, the first command used in this lesson can be used to verify that the PAE kernel has been loaded:

root@endian~#: uname -r

You can now use your Endian UTM Appliance with the new kernel!


The packages that are installed may vary over time, depending on the kernel and its dependencies. Hence, if for any reasons the smart install kernel-PAE kernel-module-*-PAE command fails, write explicitly the name of the packages on the command line. At the time of writing (December 2015) the necessary packages are:

  • kernel-firmware- (this package contains driver for various hardware devices and is in common for PAE and non-PAE kernels)
  • kernel-PAE
  • kernel-module-iptables-ndpi-PAE
  • kernel-module-ipset-PAE
  • kernel-module-vmware-drivers-PAE
  • kernel-module-igb-PAE
  • kernel-module-ixgbe-PAE
  • kernel-module-megaraid-sas-PAE
  • kernel-module-e1000e-PAE
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  • Avatar
    Junior A.

    version 2.5.2 does not apply

  • Avatar
    Romeo Andreica

    community or enterprise?

  • Avatar
    Junior A.


  • Avatar
    Junior A.

    also tried the procedure in version 3.0 beta and does not work.

    a question that will no longer be available in the community version?

  • Avatar

    To restore back the first intallation:

    smart install kernel kernel-module-e1000e kernel-module-igb kernel-module-ixgbe

  • Avatar
    Junior A.

    hi thanks go testing 

  • Avatar
    Junior A.

    I'm using Endian Firewall Community version 3.0 released 20 January 2014 but did not work, can I do anything else?

  • Avatar
    Junior A.

    Hi Luca knows tell me if the PAE kernel version will still be covered by the Community?

  • Avatar
    Junior A.

    Hi Luca knows tell me if the PAE kernel version will still be covered by the Community?

  • Avatar
    Engr. Muhammad Naeem Akhtar

    Hi Endian Team Good work, every time I run this procedure it works fine.