Usually your home directory on your Linux desktop is where most of your important files reside. When you shutdown your desktop then those files are inaccessible. If you also have a Linux laptop then it would be nice to have the same home directory available on both the desktop and the laptop.
Putting your home directory on the Linux server would solve this issue. Here we look at installing an NFS service for 24x7 availability. If you have no other Linux devices then skip this chapter.
First install the needed packages. The nfs-common package contains both client and server elements; the nfs-kernel-server contains the server daemons rpc.mountd and rpc.nfsd.
$ sudo apt install nfs-common nfs-kernel-server
...
The following NEW packages will be installed:
keyutils libevent-core-2.1-7 nfs-common nfs-kernel-server rpcbind
...
Setting up rpcbind (1.2.6-2build1) ...
Created symlink /etc/systemd/system/multi-user.target.wants/rpcbind.service ...
Created symlink /etc/systemd/system/sockets.target.wants/rpcbind.socket ...
...
Creating config file /etc/idmapd.conf with new version
Creating config file /etc/nfs.conf with new version
...
Created symlink /etc/systemd/system/multi-user.target.wants/nfs-client.target ...
Created symlink /etc/systemd/system/remote-fs.target.wants/nfs-client.target ...
...
Setting up nfs-kernel-server (1:2.6.1-1ubuntu1.2) ...
Created symlink /etc/systemd/system/nfs-client.target.wants/nfs-blkmap.service ...
Created symlink /etc/systemd/system/multi-user.target.wants/nfs-server.service ...
...
Creating config file /etc/exports with new version
Creating config file /etc/default/nfs-kernel-server with new version
...
// show NFS and RPC services which are now enabled:
$ systemctl list-unit-files --state=enabled | egrep 'nfs|rpc'
nfs-blkmap.service enabled enabled
nfs-server.service enabled enabled
rpcbind.service enabled enabled
rpcbind.socket enabled enabled
nfs-client.target enabled enabled
// show NFS and RPC processes currently running:
$ ps -ef |egrep 'nfs|rpc'
_rpc 271754 1 0 10:45 ? 00:00:00 /sbin/rpcbind -f -w
root 272176 2 0 10:46 ? 00:00:00 [rpciod]
root 272280 1 0 10:46 ? 00:00:00 /usr/sbin/rpc.idmapd
statd 272282 1 0 10:46 ? 00:00:00 /sbin/rpc.statd
root 272285 1 0 10:46 ? 00:00:00 /usr/sbin/nfsdcld
root 272286 1 0 10:46 ? 00:00:00 /usr/sbin/rpc.mountd
root 272294 2 0 10:46 ? 00:00:00 [nfsd]
root 272295 2 0 10:46 ? 00:00:00 [nfsd]
root 272296 2 0 10:46 ? 00:00:00 [nfsd]
root 272297 2 0 10:46 ? 00:00:00 [nfsd]
root 272298 2 0 10:46 ? 00:00:00 [nfsd]
root 272299 2 0 10:46 ? 00:00:00 [nfsd]
root 272300 2 0 10:46 ? 00:00:00 [nfsd]
root 272301 2 0 10:46 ? 00:00:00 [nfsd]There are a few files to configure. We remove IPv6 RPC services by commenting out udp6 and tcp6 from /etc/netconfig:
$ sudo cp -p /etc/netconfig /etc/netconfig.orig
$ sudo nano /etc/netconfig
$ diff /etc/netconfig.orig /etc/netconfig
15,16c15,16
< udp6 tpi_clts v inet6 udp - -
< tcp6 tpi_cots_ord v inet6 tcp - -
---
> #udp6 tpi_clts v inet6 udp - -
> #tcp6 tpi_cots_ord v inet6 tcp - -Before restarting the daemons we see various IPv6 processes running:
$ sudo lsof -i | grep rpc | grep IPv6
systemd 1 root 144u IPv6 899098 0t0 TCP :sunrpc (LISTEN)
systemd 1 root 145u IPv6 899100 0t0 UDP :sunrpc
rpcbind 271754 _rpc 6u IPv6 899098 0t0 TCP :sunrpc (LISTEN)
rpcbind 271754 _rpc 7u IPv6 899100 0t0 UDP :sunrpc
rpc.statd 272282 statd 10u IPv6 897604 0t0 UDP :59540
rpc.statd 272282 statd 11u IPv6 897608 0t0 TCP :47971 (LISTEN)
rpc.mount 272286 root 6u IPv6 900420 0t0 UDP :53821
rpc.mount 272286 root 7u IPv6 902332 0t0 TCP :45067 (LISTEN)
rpc.mount 272286 root 10u IPv6 902347 0t0 UDP :43059
rpc.mount 272286 root 11u IPv6 902352 0t0 TCP :39207 (LISTEN)
rpc.mount 272286 root 14u IPv6 902367 0t0 UDP :52374
rpc.mount 272286 root 15u IPv6 902372 0t0 TCP :52705 (LISTEN)
// restart the daemons (only the rpcbind ports still report IPv6)
$ sudo systemctl restart rpcbind nfs-server rpc-statdFinally, the NFS shares need to be published and shared. It is best to export /home so that logins on both the server and any clients use the same '/home' directories. If you use other directory names you need to change the home directory path in the password file, or create a symbolic link from /home to the new directory -- though we can do this, it is a bit messy.
// Edit the exports file on the NFS server:
$ sudo cp -p /etc/exports /etc/exports.orig
$ sudo nano /etc/exports
$ diff /etc/exports.orig /etc/exports
6c6,11
< #
---
>
> # Export home directories using NFSv3 syntax
> # Limit nfs access to the IP address of the client node(s)
> /home 192.168.1.65(rw,sync,no_subtree_check) \
> 192.168.1.85(rw,sync,no_subtree_check)
>Then export the share. It can then be mounted on other clients.
$ sudo exportfs -aWe will use autofs on other Linux hosts to automatically mount and unmount the home directory on demand. Note that any current directories in /home on your client will be affected, since we are going to mount the server's /home directory using the /home directory. Anything in that directory will be hidden until you unmount the server's version of /home. Consider migrating the content of /home to the server.
This example uses another Ubuntu host as the NFS client. We install autofs on it and then edit the automount map files as needed.
// install the autofs package
$ sudo apt install autofs
The following additional packages will be installed:
keyutils libevent-core-2.1-7 nfs-common rpcbind
...
Setting up rpcbind (1.2.6-2build1) ...
Created symlink /etc/systemd/system/multi-user.target.wants/rpcbind.service ...
Created symlink /etc/systemd/system/sockets.target.wants/rpcbind.socket ...
...
Setting up autofs (5.1.8-1ubuntu1.2) ...
Creating config file /etc/auto.master with new version
...
Setting up nfs-common (1:2.6.1-1ubuntu1.2) ...
...
Created symlink /etc/systemd/system/multi-user.target.wants/nfs-client.target ...
Created symlink /etc/systemd/system/remote-fs.target.wants/nfs-client.target ...
// If you are getting used to reading 'man' pages, then it is useful to use
// the 'man -k' option to get a list and description of all man pages available
// matching a topic:
$ man -k autofs
auto.master (5) - Master Map for automounter consulted by autofs
autofs (5) - Format of the automounter maps
autofs (8) - Service control for the automounter
autofs.conf (5) - autofs configuration
automount (8) - manage autofs mount points
// Now edit configuration file /etc/autofs.conf and get rid of the 'amd' section
// Keep things simple.
$ cd /etc
$ sudo cp -p autofs.conf autofs.conf.orig
$ sudo nano autofs.conf
$ diff autofs.conf.orig autofs.conf
404c404
< [ amd ]
---
> #[ amd ]
410c410
< dismount_interval = 300
---
> #dismount_interval = 300
// Edit configuration file /etc/auto.master
// We comment out the '+auto.master' line and append the auto.home configuration
$ sudo cp -p auto.master auto.master.orig
$ sudo nano auto.master
$ diff auto.master.orig auto.master
22c22
< +dir:/etc/auto.master.d
---
> #+dir:/etc/auto.master.d
38c38,43
< +auto.master
---
> #+auto.master
>
> ## This is a direct mountpoint for NFS-provided home directories ..
> /- /etc/auto.home --timeout 300
>
// We create /etc/auto.home; every regular user you create also needs
// an entry in this file.
$ sudo nano /etc/auto.home
$ cat /etc/auto.home
## For every new user you must add their home directory entry to this file.
## The IP address belongs to the Linux Server of course...
/home/myname \
-rw,hard,intr,rsize=32768,wsize=32768,retrans=2,timeo=600,tcp,nfsvers=3 \
192.168.1.90:/home/mynameNow, you would normally restart autofs - but do not do this immediately:
// restart autofs:
$ sudo systemctl restart autofsConsider your impending 'chicken-and-egg' issue regarding being a regular user logged into your home directory while you restart autofs, causing your current home directory to disappear. There is some help on this topic in the appendix. Perhaps the easiest solution if you do not want to fiddle with changes to root access is to reboot your client device. If there were no mistakes in your configuration changes then when the client is back up again you should have a home directory that is served by your home server.
$ pwd
/home/myname
$ df -h .
Filesystem Size Used Avail Use% Mounted on
192.168.1.90:/home/myname 50G 464M 50G 1% /home/mynameOnce you NFS-mount your home directory on your clients, then if for any reason your server is down you will not be able to log in as a regular user. This would be a rare condition, but it would affect your ability to work from your other devices. You need to be able to login locally so that you can address the problem.
You could give your local root user a good password, or you could create another local user on each device and give them administrative rights so that they can use sudo for root access locally:
// Suppose the other user is called 'helper'
// We will give the helper user another home directory
$ sudo mkdir /var/home
$ sudo groupadd -g 1100 helper
$ sudo useradd -u 1100 -g helper -m -d /var/home/helper -c 'Helper Account' helper
$ sudo usermod -aG sudo helper
$ grep sudo /etc/group
sudo:x:27:myname,helper
// Don't forget to set a password - presumably it would be the same as your password..
$ sudo passwd helper
[sudo] password for myname:
New password:
Retype new password:
passwd: password updated successfullyThe main benefit of letting the automounter unmount your directory when you log out is that you can easily do maintenance on the server without disturbing the state of your clients - that is, your desktop or laptop or other devices which might still be turned on.
When you log out of a client then the automounter should unmount your directory at the configured time limit - in our case - 5 minutes. But there are some misbehaved software which insists on staying around, and you might want to watch out for that software and investigate what you can do with it. Indeed, your ssh-agent (if you are using it) is not going to go away unless you kill it before logging out. This process alone will keep your home directory mounted on the client.
One solution is to let the display manager clean up for you. If you are using the lightdm display manager then you need to make a root-owned script on your Linux client that will do the job:
// Remember, this is done on your Linux client desktop, not on the server:
$ cd /etc/lightdm
$ sudo /bin/bash
# touch lightdm.conf
# nano lightdm.conf
# cat lightdm.conf
[Seat:*]
session-cleanup-script=/root/bin/clean-up-user.sh
# cd /root
// make a bin directory if you don't have one
# mkdir bin
# touch clean-up-user.sh
# chmod 755 clean-up-user.sh
# nano clean-up-user.sh
# cat clean-up-user.sh
#!/bin/sh
## This script is called by the lightdm window manager. It finds processes
## owned by users on logout, and kills them. Don't use this script if your
## users need to leave any of these processes running on logout.
procs=$(ps -ef | grep -v grep | grep '/lib/systemd/systemd --user' | grep -v '^root')
echo "$procs" | while read user process rest ; do
#echo debug: user is $user, proc is $process
if [ "$user" != "" ] ; then
#echo debug: kill $process
kill $process
fi
done
procs=$(ps -ef | grep -v grep | grep ssh-agent | grep -v '^root')
echo "$procs" | while read user process rest ; do
#echo debug: user is $user, proc is $process
if [ "$user" != "" ] ; then
#echo debug: kill $process
kill $process
fi
doneIf you are using an X2go remote desktop session then you will not go through the display manager. Therefore the above script will not be called. You can always create a copy of this script in your own ~/bin/ directory and run it from a terminal session just before logging out.