How To Run LTSP Using Fedora 16

Introduction

The LTSP (Linux Terminal Server Project) is a thin-client support to Linux servers. More about it you can find on LTSP Project website.

To do all described below operations you have to login as root.

There is the main problem with LTSP using Fedora 16: installation scripts are dedicated for Fedora 9, 10, 11 and 12 and it is necessary to prepare own configuration.

Install LTSP Software

It is necessary to download and install Fedora 16 (Fedora download page, Fedora 16 Installation Guide).

The next step is LTSP software installing:

$ yum install ltsp-server

It should install the following packages:

 ltsp-server            i686        5.1.95-3.fc16            fedora        90 k
Instalowanie, aby rozwiązać zależności:
 dhcp                   i686        12:4.2.3-3.fc16          fedora       446 k
 isomd5sum              i686        1:1.0.7-1.fc16           fedora        25 k
 ldminfod               i686        2.0.46-2.fc15            fedora        11 k
 livecd-tools           i686        1:16.9-1.fc16            updates       65 k
 ltspfs                 i686        0.5.13-2.fc15            fedora        31 k
 nbd                    i686        2.9.20-2.fc15            fedora        43 k
 pykickstart            noarch      1.99.4-1.fc16            fedora       308 k
 pyparted               i686        3.8-1.fc16               fedora       188 k
 python-imgcreate       i686        1:16.9-1.fc16            updates       92 k
 squashfs-tools         i686        4.2-1.fc16               fedora       111 k
 syslinux               i686        4.02-5.fc16              fedora       789 k
 syslinux-extlinux      i686        4.02-5.fc16              fedora       336 k
 tftp-server            i686        5.1-1.fc16               fedora        39 k
 xinetd                 i686        2:2.3.14-37.fc16         fedora       122 k

LTSP and SELinux

Yum allow to install LTSP packages for F16, but these packages is not ready to run in F16. You have to do some modifications to run LTSP. I haven't tested described below modifications with SELinux enabled (I suppose it will be problems to run LTSP with SELinux enabled). To disable SELinux edit /etc/selinux/config file, change line

SELINUX=enforcing

SELINUX=disabled

and restart your system.

Network Configuration

There is a need to establish the name of network device in system which will be use for LTSP clients. In following example it is em1. To configure this device edit /etc/sysconfig/network-scripts/ifcfg-em1 file and check/change/add setings:

DEVICE=em1			# do not change
HWADDR=xx:xx:xx:xx:xx:xx	# do not change
BOOTPROTO=static
ONBOOT=yes
NM_CONTROLLED=no
IPADDR=172.31.100.254
NETMASK=255.255.255.0
TYPE=Ethernet
IPV6INIT=no
USERCTL=no
PREFIX=24
BRIDGE=ltspbr0

In /etc/ltsp/ltsp-server.conf file change the network device name.

LTSP_DEV=em1

Server Initialize

Now, you can run script:

$ ltsp-server-initialize -y

The output can be like following:

/usr/share/ltsp//scripts.d/06-xdm-config-update:


/etc/X11/xdm/xdm-config not found

running hosts-update
running dhcpd-update

and in /etc/hosts file should be:

[...]
172.31.100.1    ws001.ltsp      ws001
172.31.100.2    ws002.ltsp      ws002
[...]
172.31.100.253  ws253.ltsp      ws253
172.31.100.254  server.ltsp     server

If there are errors in /etc/hosts file, they can be correct manually.

NetworkMenager Bug

There is the bug in NetworkMenager (starting network interfaces order is wrong) - may be needed to restart network service and DHCP service. After boot system you can test it with command:

$ /etc/init.d/network status

The output with problem:

Configurated devices:
lo em1 ltspbr0
Active devices:
lo		# there aren't em1 and ltspbr0 - there is problem

The correct output:

Configurated devices:
lo em1 ltspbr0
Active devices:
lo em1 ltspbr0	# OK - all devices are active

Another test is:

$ ifconfig

The em1 and ltspbr0 should have assigned IP addresses.

If your system have described problem, there is the solution - restart the network service. To automate this process add to /etc/rc.d/rc.local file (if there isn't this file in your system, you have to create it and change rights of it with $ chmod 755 /etc/rc.d/rc.local):

#!/bin/bash
/etc/init.d/network restart

DHCP Server Configuration

Version 1: ltsp-dhcpd

If you need DHCP server only for LTSP, you do not need to do anything - LTSP server initialize should run DHCP server. You can test it with:

$ /bin/systemctl status ltsp-dhcpd.service

The output should be:

running

If after reboot your system ltsp-dhcpd.service is dead you can add to /etc/rc.d/rc.local following line (That should be enough):

/etc/init.d/ltsp-dhcpd start

If you need DHCP server for something more than LTSP, you have to use version 2 configuration.

Version 2: without ltsp-dhcpd

If you need DHCP server for something more than LTSP, this version is for you. You have to stop ltsp-dhcpd service (it isn't works with systemctl - if you not stop it, normal DHCP Server will exit after starting.

$ chkconfig ltsp-dhcpd off		# stopping ltsp-dhcpd service
$ touch /var/lib/dhcpd/dhcpd.leases	# prophylactically if you haven't the file
$ chown dhcpd:dhcpd /var/lib/dhcpd/dhcpd.lease	# prophylactically if ltsp-dhcpd changed anything

Add to the DHCP configuration file (/etc/dhcp/dhcpd.conf):

option subnet-mask            255.255.255.0;
option broadcast-address      172.31.100.255;
option routers                172.31.100.254;
option domain-name-servers    172.31.100.254;
option domain-name            "local.org";   # You really should fix this
option option-128 code 128 = string;
option option-129 code 129 = text;


get-lease-hostnames           true;

next-server                   172.31.100.254;
option root-path              "172.31.100.254:/opt/ltsp/i386";

subnet 172.31.100.0 netmask 255.255.255.0 {
    range   172.31.100.100   172.31.100.199;
    if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
        filename "/var/lib/tftpboot/ltsp/i386/pxelinux.0";
    }
    else{
        filename "/ltsp/i386/vmlinuz-3.1.0-7.fc16.i686";
    }
}

The kernel version (filename "/ltsp/i386/vmlinuz-3.1.0-7.fc16.i686") could be another - correct it.

To test configuration you can run it:

$ systemctl start dhcpd.service

To automatically run your DHCP server do:

$ cd /etc/systemd/system/multi-user.target.wants
$ ln -s /lib/systemd/system/dhcpd.service

Warning: If you DHCP server not running after system reboot (the NetworkMenager bug described above), you can add to /etc/rc.d/rc.local file

/bin/systemctl start dhcpd.service

Preparing Kickstart Definition for LTSP Client

You have to prepare a new configuration. You should copy and change kickstart definition:

$ cp -R /etc/ltsp/kickstart/Fedora/12 /etc/ltsp/kickstart/Fedora/16
$ cd /etc/ltsp/kickstart/Fedora/16

In files ltsp-*.ks in directory /etc/ltsp/kickstart/Fedora/16 you have to:

comment or remove old mirrors and add current baseurl for F16 (I use ftp://ftp.ps.pl, but you can use other)
change release/12.ks to release/16.ks

Example for i386 architecture:

# Kickstart Definition for Client Chroot for i386

# we are going to install into a chroot, such as /opt/ltsp/i386
install

#repo --name=released-12-i386 --mirrorlist=http://mirrors.fedoraproject.org/mirrorlist?repo=fedora-12&arch=i386
#repo --name=updates-12-i386 --mirrorlist=http://mirrors.fedoraproject.org/mirrorlist?repo=updates-released-f12&arch=i386
#repo --name=temporary-12-i386 --baseurl=http://togami.com/~k12linux-temporary/fedora/12/i386/
repo --name=temporary-16-i386 --baseurl=ftp://ftp.ps.pl/pub/linux/fedora-linux/releases/16/Everything/i386/os/

%include ../common/common.ks
%include ../common/arch/i686.ks
%include ../common/release/16.ks

To change common part of kickstart do:

$ cd /etc/ltsp/kickstart/Fedora/common/release
$ cp 13.ks 16.ks

and add following lines to /etc/sysconfig/ltspdist file in case for example before e15):

    fc16)
        export VENDORDEF="Fedora"
        export RELEASEDEF=16
        export TFTPDIR=/var/lib/tftpboot
    ;;

Patches for ltsp-build-client

ltsp-build-client script without patches give otuput:

[...]
  Instalowan: xorg-x11-xfs                 ##################### [414/429]
  Instalowan: ltsp-client                  ##################### [415/429]
sed: nie można odczytać /etc/rc.d/rc.sysinit: Nie ma takiego pliku ani katalogu
sed: nie można odczytać /etc/init.d/halt: Nie ma takiego pliku ani katalogu
sed: nie można odczytać /etc/init.d/halt: Nie ma takiego pliku ani katalogu
sed: nie można odczytać /etc/init.d/halt: Nie ma takiego pliku ani katalogu
ostrzeżenie: Skrypt %post(ltsp-client-5.1.95-3.fc16.i686) nie powiódł się, stan wyjścia 2
  Instalowan: mcstrans                     ##################### [416/429]
  Instalowan: MAKEDEV                      ##################### [417/429]
  Instalowan: neon                         ##################### [418/429]
  Instalowan: xterm                        ##################### [419/429]
  Instalowan: libxml2-python               ##################### [420/429]
  Instalowan: libselinux-python            ##################### [421/429]
  Instalowan: audit-libs-python            ##################### [422/429]
  Instalowan: python-sqlite2               ##################### [423/429]
  Instalowan: e2fsprogs                    ##################### [424/429]
  Instalowan: cpp                          ##################### [425/429]
  Instalowan: less                         ##################### [426/429]
  Instalowan: tftp                         ##################### [427/429]
  Instalowan: diffutils                    ##################### [428/429]
  Instalowan: ethtool                      ##################### [429/429]

/usr/sbin/setenforce: SELinux is disabled
umount: /tmp/imgcreate-kU1vNn/install_root/sys/fs/selinux/load: nie znaleziono
umount: /tmp/imgcreate-kU1vNn/install_root/sys/fs/selinux/load: nie znaleziono
Cleaning up chroot /opt/ltsp/i386
sed: nie można odczytać /etc/rc.d/rc.sysinit: Nie ma takiego pliku ani katalogu
sed: nie można odczytać /etc/init.d/halt: Nie ma takiego pliku ani katalogu
sed: nie można odczytać /etc/init.d/halt: Nie ma takiego pliku ani katalogu
sed: nie można odczytać /etc/init.d/halt: Nie ma takiego pliku ani katalogu
error: LTSP client installation ended abnormally

Problem description: in /usr/share/ltsp/chroot-setup.d/030-configure-client script return error, because in the last line is:

/etc/init.d/halt

but it isn't exist in Fedora 16. If you prepare halt command earlier, for example in /usr/sbin/chroot-creator then chkconfig package installation return an error (/etc/init.d/ already exist).

My solution for this problem:

Download ltsp-client-5.1.95-3.fc16.i686.rpm and pyserial-2.5-2.fc15.noarch.rpm packages and move them into /opt/ltsp/ directory

Change /usr/sbin/chroot-creator script from 77 line like below (spaces before comands are important!):

        # NOTE: This part is LTSP specific
        # Copy mkinitrd configuration into /etc/sysconfig/mkinitrd before package installation
        # This allows mkinitrd to DTRT the first time.
        imgcreate.fs.makedirs(self._instroot + "/etc/sysconfig")
        imgcreate.fs.makedirs(self._instroot + "/etc/sysconfig/network-scripts")
        imgcreate.fs.makedirs(self._instroot + "/etc/kernel")
        imgcreate.fs.makedirs(self._instroot + "/etc/kernel/postinst.d")
        shutil.copyfile("/etc/ltsp/mkinitrd/sysconfig-mkinitrd",self._instroot + "/etc/sysconfig/mkinitrd")
        shutil.copyfile("/etc/ltsp/mkinitrd/sysconfig-network",self._instroot + "/etc/sysconfig/network")
        shutil.copyfile("/etc/ltsp/mkinitrd/ifcfg-eth0",self._instroot + "/etc/sysconfig/network-scripts/ifcfg-eth0")
        shutil.copyfile("/etc/ltsp/mkinitrd/ltsp-postinst.d",self._instroot + "/etc/kernel/postinst.d/ltsp")
        os.chmod(self._instroot + "/etc/kernel/postinst.d/ltsp",0755)

        #####   Patch for ltsp-client package   #####
        print("===> Patch for ltsp-client package")
        imgcreate.fs.makedirs(self._instroot + "/patch")
        shutil.copyfile("/opt/ltsp/ltsp-client-5.1.95-3.fc16.i686.rpm",self._instroot + "/patch/ltsp-client-5.1.95-3.fc16.i686.rpm")
        shutil.copyfile("/opt/ltsp/pyserial-2.5-2.fc15.noarch.rpm",self._instroot + "/patch/pyserial-2.5-2.fc15.noarch.rpm")
        #####   end of patch                    #####
                      
        # Create empty file to mark that this is a LTSP chroot
        open(self._instroot + "/etc/ltsp_chroot", 'w').write('')

Remove from /etc/ltsp/kickstart/Fedora/common/common.ks configuration file non existing packages (system-config-display, kudzu) and ltsp-client package.

Change /etc/ltsp/kickstart/Fedora/common/release/16.ks file like below:

%packages --excludedocs
dejavu-sans-fonts
dejavu-sans-mono-fonts
dejavu-serif-fonts
plymouth-theme-charge
dracut-network
# needed for lokkit which is needed by livecd-creator
system-config-firewall-base
%end

%post
#####	patch for ltsp-client	#####
echo "===> patch start"
touch /etc/init.d/halt
rpm -i /patch/ltsp-client-5.1.95-3.fc16.i686.rpm /patch/pyserial-2.5-2.fc15.noarch.rpm 
echo "===> patch end"
#####	end of patch		#####
/usr/sbin/plymouth-set-default-theme charge
/usr/sbin/ltsp-rewrap-latest-kernel
%end

Patch for Kernel 3.x

Fedora 16 based on 3.x kernel. You have change /usr/share/ltsp/plugins/functions file in 66 line. Original line:

	kernelversion="`ls -d $ROOT/lib/modules/2* | sort -nr | head -n1 | xargs basename`"

should be changed to:

	kernelversion="`ls -d $ROOT/lib/modules/3* | sort -nr | head -n1 | xargs basename`"

Generating Client Environment

Run ltsp-build-client. The output:

Autoconfigured Kickstart: /etc/ltsp/kickstart/Fedora/16/ltsp-i386.ks
Installing into /opt/ltsp/i386
Mounting /opt/ltsp/i386 for chroot installation
===> Patch for ltsp-client package
WARNING:root:Skipping (/sys/fs/selinux,/sys/fs/selinux) because source doesn't exist.
mount: punkt montowania /tmp/imgcreate-9lPbjO/install_root/sys/fs/selinux/load nie istnieje
WARNING:root:No such package nss_db to remove
WARNING:root:No such package hal to remove
WARNING:root:No such package bluez-gnome to remove
WARNING:root:No such package libvolume_id to remove
WARNING:root:No such package iptables-ipv6 to remove
WARNING:root:No such package pam_smb to remove
WARNING:root:No such package firstboot-tui to remove
WARNING:root:No such package cpuspeed to remove
WARNING:root:No such package man to remove
WARNING:root:No such package unix2dos to remove
WARNING:root:No such package htmlview to remove
WARNING:root:No such package rng-utils to remove
WARNING:root:No such package ifd-egate to remove
WARNING:root:No such package vixie-cron to remove
WARNING:root:No such package rhpl to remove
WARNING:root:No such package ccid to remove
WARNING:root:No such package anacron to remove
WARNING:root:No such package bluez-utils to remove
WARNING:root:No such package sysreport to remove
ostrzeżenie: fontpackages-filesystem-1.44-2.fc15.noarch: Nagłówek V3 RSA/SHA256 Signature, identyfikator klucza a82ba4b7: NOKEY
  Instalowan: fontpackages-filesystem      ##################### [  1/427] 
  Instalowan: setup                        ##################### [  2/427] 
  Instalowan: filesystem                   ##################### [  3/427] 
[...]
  Instalowan: gawk                         ##################### [ 80/427] 
  Instalowan: libidn                       ##################### [ 81/427] 
install-info: Nie ma takiego pliku ani katalogu for /usr/share/info/libidn.info.gz
  Instalowan: cpio                         ##################### [ 82/427] 
  Instalowan: pcre                         ##################### [ 83/427] 
  Instalowan: grep                         ##################### [ 84/427] 
install-info: Nie ma takiego pliku ani katalogu for /usr/share/info/grep.info.gz
  Instalowan: libsigc++20                  ##################### [ 85/427] 
  Instalowan: openjpeg-libs                ##################### [ 86/427] 
[...]
  Instalowan: pinentry                     ##################### [178/427] 
  Instalowan: which                        ##################### [179/427] 
install-info: Nie ma takiego pliku ani katalogu for /usr/share/info/which.info.gz
  Instalowan: e2fsprogs-libs               ##################### [180/427] 
  Instalowan: libss                        ##################### [181/427] 
[...]
  Instalowan: plymouth-scripts             ##################### [271/427] 
  Instalowan: plymouth                     ##################### [272/427] 
Need 'inst' function, try setting PLYMOUTH_POPULATE_SOURCE_FUNCTIONS to a file that defines it
  Instalowan: dracut                       ##################### [273/427] 
  Instalowan: kernel                       ##################### [274/427] 
[...]
  Instalowan: yp-tools                     ##################### [289/427] 
  Instalowan: ypbind                       ##################### [290/427] 
Running in chroot, ignoring request.
  Instalowan: xorg-x11-drv-void            ##################### [291/427] 
  Instalowan: xorg-x11-drv-synaptics       ##################### [292/427] 
[...]
  Instalowan: libcurl                      ##################### [352/427] 
  Instalowan: gnupg2                       ##################### [353/427] 
install-info: Nie ma takiego pliku ani katalogu for /usr/share/info/gnupg.info
  Instalowan: dhcp-common                  ##################### [354/427] 
  Instalowan: dhclient                     ##################### [355/427] 
[...]
  Instalowan: cpp                          ##################### [423/427] 
  Instalowan: less                         ##################### [424/427] 
  Instalowan: tftp                         ##################### [425/427] 
  Instalowan: diffutils                    ##################### [426/427] 
  Instalowan: ethtool                      ##################### [427/427] 

===> patch start
warning: /patch/ltsp-client-5.1.95-3.fc16.i686.rpm: Header V3 RSA/SHA256 Signature, key ID a82ba4b7: NOKEY
sed: can't read /etc/rc.d/rc.sysinit: No such file or directory
===> patch end
/usr/sbin/setenforce: SELinux is disabled
umount: /tmp/imgcreate-9meeRG/install_root/sys/fs/selinux/load: nie znaleziono
umount: /tmp/imgcreate-9meeRG/install_root/sys/fs/selinux/load: nie znaleziono
Cleaning up chroot /opt/ltsp/i386
sed: nie można odczytać /etc/rc.d/rc.sysinit: Nie ma takiego pliku ani katalogu
WARNING: /opt/ltsp/temporary-16-i386/etc/ssh not found. skipping...
Updating /var/lib/tftpboot directories for chroot: /opt/ltsp/i386
Skipping invalid chroot: /opt/ltsp/temporary-16-i386
info: LTSP client installation completed successfully

Firewall Configuration

Run from menu: Programs > Administration > Firewall and open ports: 69 (TFTP), 111 (sunrpc) and NFS4 (2049). Change tab to "Other ports" and add:

111	tcp (sunrpc)
111	udp (sunrpc)
20048	udp (mountd)

Restart firewall. In /etc/sysconfig/iptables file should be:

-A INPUT -m state --state NEW -m tcp -p tcp --dport 2049 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A INPUT -m state --state NEW -m udp -p udp --dport 69 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 111 -j ACCEPT
-A INPUT -m state --state NEW -m udp -p udp --dport 111 -j ACCEPT
-A INPUT -m state --state NEW -m udp -p udp --dport 20048 -j ACCEPT

Run LTSP

Now you can try to run LTSP client :)
The start procedure with using PXE:

Client gets IP address from DHCP server
Client gets kernel using TFTP
Client print "boot:" string
Type "linux" and press Enter
Client show login screen
If you first start client, you can get error message about mountd. You should execute on server
```
exportfs -a
```
and restart client. The next start should be OK (is this bug in rpc.mound?)

Client kernel options can be changed in /var/lib/tftpboot/ltsp/i386/pxelinux.cfg/default file on server.
International settings can be changed in /var/lib/tftpboot/ltsp/i386/lts.conf in [default] section, for example:

LC_ALL=pl_PL.UTF-8
LANG=pl_PL.UTF-8
XKBLAYOUT=pl2
KEYTABLE=pl2

but in some cases you have to change them after login in client X desktop configuration (for example keyboard layout).

If you want to start client from local hard disk, you should copy following files from /var/lib/tftpboot/ltsp/i386 server directory into client hard disk /boot directory:

config-3.1.0-7.fc16.i686
initramfs-3.1.0-7.fc16.i686.img
System.map-3.1.0-7.fc16.i686
vmlinuz-3.1.0-7.fc16.i686

change network configuration file /etc/sysconfig/network-scripts/ifcfg-em1

DEVICE=em1
# Your network card MAC address
HWADDR=xx:xx:xx:xx:xx:xx
BOOTPROTO=none
#ONBOOT=no
ONBOOT=yes
NM_CONTROLLED=yes
IPADDR=172.31.100.102
NETMASK=255.255.255.0
TYPE=Ethernet
GATEWAY=172.31.100.254
IPV6INIT=no
USERCTL=no
PREFIX=24

and add new item to client grub start menu /boot/grub2/grub.cfg (51d0fe25-b473-48a4-a86a-be13cd549bd1 change to UUID your hard disk partition):

[...]
menuentry 'LTSP Client' --class fedora --class gnu-linux --class gnu --class os {
 	load_video
 	set gfxpayload=keep
 	insmod gzio
 	insmod part_msdos
 	insmod ext2
 	set root='(hd0,msdos1)'
 	search --no-floppy --fs-uuid --set=root 51d0fe25-b473-48a4-a86a-be13cd549bd1
 	echo	'Loading Linux 3.1.0-7.fc16.i686 ...'
 	linux	/boot/vmlinuz-3.1.0-7.fc16.i686 rw selinux=0 root=dhcp quiet rhgb LANG=pl_PL.UTF-8  KEYTABLE=pl2
 	echo	'Loading initial ramdisk ...'
 	initrd	/boot/initramfs-3.1.0-7.fc16.i686.img

Troubleshooting

Check TFTP service config /etc/xinetd.d/tftp file:

# default: off
# description: The tftp server serves files using the trivial file transfer \
#	protocol.  The tftp protocol is often used to boot diskless \
#	workstations, download configuration files to network-aware printers, \
#	and to start the installation process for some operating systems.
service tftp
{
	disable	= no
	socket_type		= dgram
	protocol		= udp
	wait			= yes
	user			= root
	server			= /usr/sbin/in.tftpd
	server_args		= -s /var/lib/tftpboot
	per_source		= 11
	cps			= 100 2
	flags			= IPv4
}

Check if xinetd service is running
```
systemctl status xinetd.service
```

Check portmapper service

rpcinfo -p localhost

should output:

   program vers proto   port  service
    100000    4   tcp    111  portmapper
    100000    3   tcp    111  portmapper
    100000    2   tcp    111  portmapper
    100000    4   udp    111  portmapper
    100000    3   udp    111  portmapper
    100000    2   udp    111  portmapper

Change 47 line in /etc/ltsp/dhcpd.conf Original line:

	filename      "/ltsp/i386/elf.ltsp";

change to:

	filename      "/ltsp/i386/pxelinux.0";

Check NFS service.

systemctl status netfs.service

Above can show NFS service is running, but it doesn't work. Better way is:

rpcinfo -p localhost

The output should be:

    100003    2   tcp   2049  nfs
    100003    3   tcp   2049  nfs
    100003    4   tcp   2049  nfs
    100227    2   tcp   2049  nfs_acl
    100227    3   tcp   2049  nfs_acl
    100003    2   udp   2049  nfs
    100003    3   udp   2049  nfs
    100003    4   udp   2049  nfs
    100227    2   udp   2049  nfs_acl
    100227    3   udp   2049  nfs_acl
[...]
    100005    1   udp  20048  mountd
    100005    1   tcp  20048  mountd
    100005    2   udp  20048  mountd
    100005    2   tcp  20048  mountd
    100005    3   udp  20048  mountd
    100005    3   tcp  20048  mountd

and

ps axw | grep rpc

The output:

[...]
 1400 ?        Ss     0:00 /usr/sbin/rpc.mountd
[...]

If there isn't rpc.mountd, you can add following lines to /etc/rc.d/rc.local file:

/usr/sbin/rpc.nfsd 
/usr/sbin/rpc.mountd