Setting up a X server for diskless clients¶
Describes setup for diskless X clients based on alix boards from pcengine.ch
the server needs tftp and NFS
settings for NFS (/etc/exports):
/opt/alixboot (ro,no_root_squash,async)
settings for tftp (pxelinux.cfg/default):
DEFAULT vmlinuz ro initrd=initrd.img root=/dev/nfs ip=dhcp nfsroot=192.33.96.202:/opt/alixboot/
Changes to a standard Debian (etch) in /opt/alixboot:
Create tmpfs dirs
mkdir /tmp.rmdsk /etc.rmdsk /var.rmdsk
chmod 777 /tmp.rmdsk
/etc/fstab:
proc /proc proc defaults 0 0
sysfs /sys sysfs defaults 0 0
tmpfs /dev/shm tmpfs defaults,noatime 0 0
devpts /dev/pts devpts defaults,noatime 0 0
tmpfs /tmp.rmdsk tmpfs defaults,noatime 0 0
tmpfs /var.rmdsk tmpfs defaults,noatime 0 0
tmpfs /etc.rmdsk tmpfs defaults,noatime 0 0
unionfs /etc unionfs dirs=/etc.rmdsk=rw:/etc=nfsro 0 0
unionfs /var unionfs dirs=/var.rmdsk=rw:/var=nfsro 0 0
unionfs /tmp unionfs dirs=/tmp.rmdsk=rw:/tmp=nfsro 0 0
this mounts writable tmpfs overlays onto the ro NFS export
/etc/mtab:
tmpfs /lib/init/rw tmpfs rw,nosuid,mode=0755 0 0
proc /proc proc rw,noexec,nosuid,nodev 0 0
sysfs /sys sysfs rw,noexec,nosuid,nodev 0 0
udev /dev tmpfs rw,mode=0755 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
devpts /dev/pts devpts rw,noexec,nosuid,gid=5,mode=620 0 0
rootfs / rootfs ro 0 0
rm /etc/rcS.d/S40networking
prevent dhcpclient from messing with the network config
etc/inittab:
6:23:respawn:/sbin/getty 38400 tty6
kk:2345:respawn:X -query pomfrey.ethz.ch
start X and point it to a (powerful) X application server
/etc/mkinitrd/modules:
nfs
nfs_acl
lockd
these are needed in the initrd to mount NFS /
then remake initrd: dpkg-reconfigure linux-image-..
etc/default/rc:
RAMRUN=yes
RAMLOCK=yes
for initial writability in /var
ln -s /tmp/ usr/share/X11/xkb/compiled
needed for X - keyboard doesn't work w/o