Chapter 24. Setting up a Remote Diskless System
To set up a basic remote diskless system booted over PXE, you need the following packages:
tftp-serverxinetddhcpsyslinuxdracut-networkNote
After installing thedracut-networkpackage, add the following line to/etc/dracut.conf:add_dracutmodules+=" nfs"
Remote diskless system booting requires both a
tftp service (provided by tftp-server) and a DHCP service (provided by dhcp). The tftp service is used to retrieve kernel image and initrd over the network via the PXE loader.
Note
SELinux is only supported over NFSv4.2. To use SELinux, NFS must be explicitly enabled in
/etc/sysconfig/nfs by adding the line:
RPCNFSDARGS="-V 4.2"
Then, in
/var/lib/tftpboot/pxelinux.cfg/default, change root=nfs:server-ip:/exported/root/directory to root=nfs:server-ip:/exported/root/directory,vers=4.2.
Finally, reboot the NFS server.
The following sections outline the necessary procedures for deploying remote diskless systems in a network environment.
Important
Some RPM packages have started using file capabilities (such as
setcap and getcap). However, NFS does not currently support these so attempting to install or update any packages that use file capabilities will fail.
24.1. Configuring a tftp Service for Diskless Clients
Prerequisites
- Install the necessary packages. See Chapter 24, Setting up a Remote Diskless System
Procedure
To configure
tftp, perform the following steps:
Procedure 24.1. To Configure tftp
- Enable PXE booting over the network:
#systemctl enable --now tftp - The
tftproot directory (chroot) is located in/var/lib/tftpboot. Copy/usr/share/syslinux/pxelinux.0to/var/lib/tftpboot/:#cp /usr/share/syslinux/pxelinux.0 /var/lib/tftpboot/ - Create a
pxelinux.cfgdirectory inside thetftproot directory:#mkdir -p /var/lib/tftpboot/pxelinux.cfg/ - Configure firewall rules to allow
tftptraffic.Astftpsupports TCP wrappers, you can configure host access totftpin the/etc/hosts.allowconfiguration file. For more information on configuring TCP wrappers and the/etc/hosts.allowconfiguration file, see the Red Hat Enterprise Linux 7 Security Guide. The hosts_access(5) also provides information about/etc/hosts.allow.
Next Steps
After configuring
tftp for diskless clients, configure DHCP, NFS, and the exported file system accordingly. For instructions on configuring the DHCP, NFS, and the exported file system, see Section 24.2, “Configuring DHCP for Diskless Clients” and Section 24.3, “Configuring an Exported File System for Diskless Clients”.
