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7.8.1 Configure a Root File System
The idea behind a diskless node is to use the distribution that has been installed on a remote
server via NFS. We used a two step process to create the root file system for a client on the
server.
1. Copy all files from the distribution installed on a disk into a directory on the server.
NFSROOT=/NFSroot/clients/OS/client1.
The directory
/NFSroot/clients/OS/client1
is the distribution root directory. In addition,
create a directory
/NFSroot/clients/OS/client1/initrd
since we make
use of this in the ramdisk with pivot_root.
2. Prepare the copied distribution directory for network booting.
a. Replace the entry for
/
in
${NFSROOT}/etc/fstab
with
none / tmpfs defaults 0 0
This will prevent an
fsck.ext2
b. Ensure that all NFS mounts in
${NFSROOT}/etc/fstab
have the
nolock
option turned on.
c. Disable networking (we set this up in the ramdisk over AMSO1100)
/usr/sbin/chroot ${NFSROOT} /sbin/chkconfig \
--del network
d. Create the following symbolic links since
/etc
will be read-only
ln -sf /proc/mounts ${NFSROOT}/etc/mtab
ln -sf /var/resolv.conf \
${NFSROOT}/etc/resolv.conf
More info on creating NFS root filesystems can be obtained at:
http://www.tldp.org/HOWTO/NFS-Root-Client-mini-HOWTO/
7.8.2 Configure the NFS Server
The NFS server should export the distribution directory. Add a line like this to your
/etc/exports
on the NFS server:
/NFSroot/clients/OS/client1 \
10.40.48.0/255.255.0.0(ro,no_root_squash)
Run
/usr/sbin/exportfs -ra
after you have added the line and restart the NFS
daemon. This directory should not be mounted in read-write mode since you need to set
no_root_squash
.
More info on configuring an NFS server can be found at the following web site:
http://www.tldp.org/HOWTO/NFS-HOWTO/