PXE Install and Rescue Server

If you want to install or rescue your ClearOS server from over your network or the Internet, you can install the software using PXE (Preboot Execution Environment). The instructions below detail how to configure a PXE Boot Server on ClearOS. The PXE Boot Server can then be used to install other ClearOS systems, or just other software in general.



  • Modern BIOS with a PCI or an on-board network card.

Web, DHCP and TFTP Servers

  • app-flexshare and app-httpd (Web)
  • app-dnsmasq (TFTP and DHCP)
  • syslinux
  • rsync


The following example goes through setting up a PXE server on ClearOS Enterprise.

Installing the Required Software

You need to install a few base software packages to get going:

yum install app-flexshare app-httpd app-dnsmasq syslinux rsync

Configuring the Download Server with Flexshare

Next, you should create a web download share using Flexshares. This is where you will store a copy of the ClearOS install files. In the example, create a share called pxe and make sure Web access is enabled and turning on the Indexes feature is recommended. You may want to enable Windows File Sharing or FTP upload the ClearOS install files to the system.

Downloading the Files

Next, you need to create the directory structure for your PXE environment. We suggest using the following, but feel free to change this to suit your needs:

mkdir -p /var/flexshare/shares/pxe/clearos/enterprise/5.1

Copy the files from the ClearFoundation download servers. The best tool for the job is rsync, but you can also use FTP and other file management tools.

cd /var/flexshare/shares/pxe/clearos/enterprise/5.1
rsync -rltv --progress .


cd /var/flexshare/shares/pxe/clearos/enterprise/5.1

At this stage, you should make sure you can view your files via a web browser. The flexshare URL is /flexshare/pxe, e.g.

Configuring the TFTP Server

The next step is to enable the TFTP server. On ClearOS, this is provided by the Dnsmasq software. In /etc/dnsmasq.conf, add the following parameters:


If necessary, copy the PXE boot image into the TFTP server directory:

cp /usr/lib/syslinux/pxelinux.0 /var/flexshare/shares/pxe/clearos/enterprise/5.1/images/pxeboot

Configuring the DHCP Server

To inform PXE clients that a boot server exists on your network, you need to configure your DHCP Server. This should be done using the webconfig tool on ClearOS.

Then, you can add the following option to the /etc/dnsmasq.conf file to configure the boot server entry:


Change tftp-server-hostname to the hostname for the TFTP server, and tftp-server-IP to the IP address of the server. Here's an example:


After the configuration change, restart the DHCP server:

service dnsmasq restart

Note: you do not need to run your DHCP and TFTP from the same machine.

Client Configuration

On your target install system, make sure the system is configured with PXE enabled. You may need to dig into the BIOS to find these settings. If all goes well, you should see a ClearOS installer screen pop up. From there, you can follow the usual procedure to install the ClearOS over the network.

content/en_us/kb_howtos_installing_via_pxe_enabled_network_card.txt · Last modified: 2015/03/01 17:47 (external edit)