Tag Archive: rpi


Now, let’s get started with NFS, right? Well… first things first… this configuration is supposed to replace the BeagleBoard. As mentioned, I have occidentally overwritten its SD card. This also means I cannot access its current configuration.

I cannot login to the device anymore over ssh or serial connection due incorrect content of the root filesystem. However the NFS server is still serving perfectly fine. Since I cannot login, I cannot gracefully unmount the filesystems. The point is, I am listening to music. The music is on the USB hard disks connected to the BeagleBoard, which I will have to shut down in order to connect them to the Raspberry Pi to configure the mount points. If I could access the old configureation, I could just copy over the entries in /etc/fstab.

I will be using UUIDs to identify the partition to mount, as, when using USB, I cannot predict which device name it will have. I mean, if I disconnect, and reconnect the hard disks on a different USB port, I wish not to have to change the configuration. Therefore I will use UUIDs so no matter what device name it gets, it will work. So, let’s delay configuring the mount points to a later point. We will configure the mount points (same as currently on the BeagleBoard):

/mnt/1000 : 1000 GB USB HARD DISK, DATA
/mnt/1500 : 1500 GB USB HARD DISK, DATA
/home : 250 GB USB HARD DISK, HOME PARTITION

If I just create the directories, the rest of the procedure should work, and the actual hard disks can be added later. Let’s install the NFS software. Also… let’s install vim, the editor I am used to, as it isn’t installed by default in an ArchLinux installation (vi and nano are)

# pacman -S nfs-utils vim

For security reasons, we will set up an nfs root

# mkdir /srv/nfs4
# mkdir /srv/nfs4/1000
# mkdir /srv/nfs4/1500
# mkdir /srv/nfs4/andre

and add the following to /etc/fstab

/mnt/1000 /srv/nfs4/1000 none bind 0 0
/mnt/1500 /srv/nfs4/1500 none bind 0 0
/home/andre /srv/nfs4/andre none bind 0 0

and set up the exports in /etc/exports

/srv/nfs4/ 192.168.178.1/24(rw,fsid=0,no_subtree_check)
/srv/nfs4/1000 192.168.178.1/24(rw,no_subtree_check,nohide)
/srv/nfs4/1500 192.168.178.1/24(rw,no_subtree_check,nohide)
/srv/nfs4/andre 192.168.178.1/24(rw,no_subtree_check,nohide)

To start the nfs server, just now

# systemctl start nfsd.service rpc-idmapd.service rpc-mountd.service rpcbind.service

Verifying the exports from my desktop machine:

$ showmount -e 192.168.178.49
Export list for 192.168.178.49:
/srv/nfs4/andre 192.168.178.1/24
/srv/nfs4/1500 192.168.178.1/24
/srv/nfs4/1000 192.168.178.1/24
/srv/nfs4 192.168.178.1/24

Since this looks fine, I can enable startup during boot using

# systemctl enable nfsd.service rpc-idmapd.service rpc-mountd.service rpcbind.service

This is the new way of configuring services at boot, as compared to the old /etc/rc.conf method.

So, I guess it’s about time to shut down the BeagleBoard and replace it by the Raspberry Pi. Even though there are some more services to be configured, such as my IPv6 tunnel, printer server, scanner server, and so on. As I am unable to gracefully shut the BeagleBoard down, and due its instability, I guess I’d better fsck all the external hard disks before putting them online in the new configuration.

One thing to verify before proceeding is to verify the Raspberry Pi boots up headless, and I’ve heard this might be an issue. However, the system comes up perfectly fine.

In order to listen some music while these operations are in progress, I will revert to vinyl. The real way to listen to music ;)
PS. I bought this record last wednesday. It’s awesome to see new music appear on vinyl only ;)

So, let’s continue configuring that Raspberry Pi, right? First, I would like to observe some weird behaviour. Please note I have attached a monitor, keyboard and screen to the Raspberry Pi, so I am not using a serial console, as I did when I configured my BeagleBoard.

The Raspberry Pi supports my monitors resolution 1280×1024, while the BeagleBoard does not (at a refresh rate high enough to be accepted by the monitor…. details) Another difference is that it works “out-of-the-box” on the Raspberry Pi. Just plug the monitor in and power it on. It will find out what resolution to use by itself, while the BeagleBoard required it as a kernel parameter.

The BeagleBoard is advertised as a developer board, while the Raspberry Pi aims at being a teaching tool. Another difference between those boards is that the BeagleBoard has a mounted RS-232 connector, while the Raspberry Pi only has the UART to pins on the expansion header, which is 3.3 Volt level. Therefore some level converters are required to be able to use this thing. I have ordererd this one on DX.com. The name says TTL, but in the specs it says “VCC: 3V / 5V”, therefore I think this one will do the trick. But I guess I will have to verify the voltage, as the Raspberry is *not* 5V tolerant.

DX.com, the chinese webshop, selling all kinds of stuff. I have ordered stuff there before. Free shipping, it may take a while to get it, but it’s for free. Not all my orders there have been without problems, but their customer services are good. If there are any problems, they offer replacement of refund. No difficult questions asked.

Anyways, why did I even start talking about the monitor being connected stuff, well, it’s because I am unable to log in (as root, I haven’t created users yet) on tty2, tty5 and tty6. But it works on tty1, tty3 and tty4. Looking at /var/log/auth.log

Nov 17 10:15:54 rpi-server login: pam_unix(login:session): session opened for user root by LOGIN(uid=0)
Nov 17 10:15:54 rpi-server systemd-logind[98]: New session c1 of user root.
Nov 17 10:15:54 rpi-server login: ROOT LOGIN ON tty1
Nov 17 10:16:04 rpi-server login: pam_securetty(login:auth): access denied: tty ‘tty2’ is not secure !
Nov 17 10:16:12 rpi-server login: FAILED LOGIN 1 FROM tty2 FOR root, Authentication failure

So, we see a successful login and an unsuccessful one. They’re similar for the other tty’s mentioned. Asking this question go Google gives me securetty. /etc/securetty is a text file which lists the tty’s where root is allowed to login. The content of this file agrees with the observed behaviour.

Still the question remains, why was it preconfigured with this content in the /etc/securetty file? One can assume it has been made for testing purposed, forgot about it, and ended in the image. Or is there a Raspberry Pi specific reason for doing this? Anyhow. I was planning to use this Raspberry Pi headless, so it doesn’t matter at this moment. However I am thinking about using a second Pi as desktop machine.

Well… the mystery has been solved. Let’s continue configuring this thing. Setting it up as NFS server… I am not sure if I have described this before when I’ve set this up on my BeagleBoard. However, due the conversion of ArchLinux to systemd, it would be outdated anyways.

Anyhow, since I’ve typed quite a lot already, the NFS configuration will go to yet another post. I have written two posts and the only thing I’ve done yet is booted it up, set root password and hostname.

PS: I’ve found an interesting link:Small Linux PCs overview