Installation guide

Chapter 19. Setting Up A Remote Diskless System
116
allow booting;
allow bootp;
class "pxeclients" {
match if substring(option vendor-class-identifier, 0, 9) = "PXEClient";
next-server server-ip;
filename "linux-install/pxelinux.0";
}
Replace server-ip with the IP address of the host machine on which the tftp and DHCP services
reside. Now that tftp and DHCP are configured, all that remains is to configure NFS and the
exported file system; refer to Section 19.3, “Configuring an Exported File System for Diskless Clients”
for instructions.
19.3. Configuring an Exported File System for Diskless
Clients
The root directory of the exported file system (used by diskless clients in the network) is shared via
NFS. Configure the NFS service to export the root directory by adding it to /etc/exports. For
instructions on how to do so, refer to Section 10.6.1, “ The /etc/exports Configuration File”.
To accommodate completely diskless clients, the root directory should contain a complete Red Hat
Enterprise Linux installation. You can synchronize this with a running system via rsync, as in:
rsync -a -e ssh --exclude='/proc/*' --exclude='/sys/*' hostname.com:/ /
exported/root/directory
Replace hostname.com with the hostname of the running system with which to synchronize via
rsync. The /exported/root/directory is the path to the exported file system.
Alternatively, you can also use yum with the --installroot option to install Red Hat Enterprise
Linux to a specific location. For example:
yum groupinstall Base --installroot=/exported/root/directory
The file system to be exported still needs to be configured further before it can be used by diskless
clients. To do this, perform the following procedure:
1. Configure the exported file system's /etc/fstab to contain (at least) the following configuration:
none /tmp tmpfs defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
2. Select the kernel that diskless clients should use (vmlinuz-kernel-version) and copy it to
the tftp boot directory:
cp /boot/vmlinuz-kernel-version /var/lib/tftpboot/
3. Create the initrd (i.e. initramfs-kernel-version.img) with network support:
dracut initramfs-kernel-version.img vmlinuz-kernel-version
Copy the resulting initramfs-kernel-version.img into the tftp boot directory as well.
4. Edit the default boot configuration to use the initrd and kernel inside /var/lib/tftpboot.
This configuration should instruct the diskless client's root to mount the exported file system (/