Mounting root filesystem via nfs

This document (3321720) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Desktop 11
SUSE Linux Enterprise Desktop 10
SUSE Linux Enterprise Server 11
SUSE Linux Enterprise Server 10

Situation

You want to boot a SLES system as a diskless client. The description found in the kernel sources under/usr/src/linux/Documentation/nfsroot.txt will not work with most precompiled SUSE kernels. The reason is, that the option

CONFIG_NFS_ROOT

is not set in the SUSE kernel. So the kernel itself is not configured to support mounting the root filesystem from a NFS share.

Resolution

On SLES systems it is not necessary, that the kernel itself has the CONFIG_NFS_ROOT option set. Instead you can add NFS-root support to the INITRD (initial ramdisk) to mount the root filesystem from NFS.

After you have installed the client system on the NFS server machine, chroot into the installed system and call up the mkinitrd command with the following options:

mkinitrd -m "nfs e1000" -D eth0

From SLE 11 on, the following command has to be used:

mkinitrd -f nfs -m e1000 -D eth0

In this example the command adds NFS-root support plus a network driver (e1000) plus a DHCP client to the INITRD. The DHCP client will fetch the IP-adress via eth0.

Additional Information

You will find further information on configuring the INITRD in the manual page (man 8 mkinitrd). For a general overview over the concept of the INITRD see the the Knowledgebase article Booting with the initial ramdisk.

Disclaimer

This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.