Raspberry Pi Guide

[Yorus]

Great as always Cobito.

Later on the PC I will see it in more detail, but I see very interesting things. I will comment more later.

[deeiivid]

Hello, your guide is very good, I have read it (without the videos) and I have found it amazing.

It will be very useful to me, because since raspberry is based on debian I will be able to use many of the things you say, especially the whole topic of SSH will be very useful to me, which I only knew about for iphone issues and stuff like that.

It is a pride to have you in the photo, regards and congratulations!

[Yorus]

Well, now I'm expanding more, since the 7" Chinese tablet doesn't give much more of itself. I also haven't seen the videos because I'm still using 3G.

The only thing I've done so far is installing Raspbian, although through the RaspbianInstaller which is very simple, setting up the network with a fixed IP, SSH and transmission-daemon. Apart from fixing a few things, I will install Apache+PHP just as you put it but to use TinYCMS which is very light and doesn't use MySQL.

Another thing I'm still not clear about is how I'll share the data with other devices, whether I'll use NFS or SAMBA, since initially it will share data with the desktop (Linux) and with the Western Digital player that supports NFS and SAMBA (or Windows, that is), but I've never tried NFS, so we'll see.

I liked the electronic control part, because I hadn't stopped to see how it worked but it seems very simple. I have in mind to do something with Arduino, although they are just ideas, and it could be useful for me to use the Raspberry as a control center, since it will always be on.

I'm served with the multimedia issue, so I won't test it there, besides my version is the 256Mb one.

Everything is very interesting, sir

[cobito]

@Yorus:

A parte de corregir algunas cosas instalaré Apache+PHP tal y como pones pero para usar TinYCMS que es muy ligero y no usa MySQL.

No conocía Tinycms. Yo he instalado Drupal y la verdad es que tiene un tiempo de respuesta un poco lento. Un día de estos probaré ese a ver qué tal va. Supongo que por el simple hecho de no tirar de MySQL el rendimiento ya debe ser muy superior.

@Yorus:

Otra cosa que aún no tengo clara es como haré para compartir los datos con otros dispositivos, si usaré NFS o SAMBA, ya que en un principio compartirá datos con el sobremesa (Linux) y con el reproductor Western Digital que soporta NFS y SAMBA (o Windows, vamos), pero nunca he probado NFS, así que veremos.

Pues yo todavía no he configurado ningún sismtema de intercambio de archivos local ya que de momento lo gestiono todo por SSH que también admite el intercambio de archivos. Según lei hace poco, NFS se merienda en rendimiento a Samba, FTP o SSH. De hecho SSH desde ya os puedo decir que es bastante lento (tasas de algo más de 2 mbytes/s).

@Yorus:

Me ha gustado la parte de control electrónico, porque no me había parado a ver como iba pero parece muy sencillo. Tengo en mente hacer algo con Arduino, aunque solo son ideas, y me podría ser útil usar el Raspberry como centro de control, ya que va a estar siempre encendido.

La única precaución que debes tener (ahora me doy cuenta de que no he puesto en la guía) es que los pines GPIO no son buffered, lo que significa que no están protegidos de ninguna forma. Eso se traduce en que cualquier error en las conexión: una sobretensión, un cortocircuito, etc, podría petar todo el SoC.

[Yorus]

@cobito:

Well, I still haven't set up any local file sharing system since I currently manage everything via SSH, which also supports file sharing. According to what I read recently, NFS eats into the performance of Samba, FTP, or SSH. In fact, SSH is already quite slow (rates of just over 2 mbytes/s).

Now I've just set up NFS on the desktop and I can already see it from the media player, I didn't expect it to be that simple. The issue is summarized more or less in:

apt-get install nfs-common nfs-kernel-server gedit /etc/exports /etc/init.d/nfs-kernel-server restart  

In exports, what we do is add a line like this:

/media/datos/share 192.168.1.10(rw,no_root_squash) 

where we put the directory to share and with whom we want to share it, as well as whether it can be read, written, etc... And every time we make a change, we restart the service.

This in Mint, but I don't think the package names will change much in Debian/Raspbian.

[deeiivid]

PD: Cobito! very good the thing with the little monkey :ugly: I did not leave him alone until the end xD

[deeiivid]

I am testing SSH control on the server over the internet (I am not where the server is now)
and the graphic performance is TERRIBLE, it goes much, much slower than using VNC and I do not understand why…

I clarify that I am running the ssh client from OSX, which being UNIX-based and with Xquartz (X11 manager) should work well, right?

[cobito]

@deeiivid:

I'm testing SSH control on the server over the internet (I'm not where the server is now)
and the graphic performance is TERRIBLE, it goes much much slower than using VNC and I don't understand why…

To clarify, I'm running the ssh client from OSX, which being UNIX-based and with Xquartz (X11 manager) should work well, right?

With the Raspi, the performance of launching graphical applications over SSH is better than launching them locally from the desktop environment. And if they are not applications with heavy libraries like QT, there are no big differences between accessing from the local network or from the Internet.

If you can, try from a PC with Linux to rule out server configuration or other problems.

[deeiivid]

@cobito:

With the Raspi, the performance of launching graphical applications over SSH is better than launching them locally from the desktop environment. And if they are not applications with heavy libraries like QT, there are no big differences between accessing them from the local network or from the Internet.

If you can, try it from a PC with Linux to rule out server configuration or other problems.

I've tried it with the file manager of lxde and also with transmission and it was crazy... I'm going to run knoppix and see how it goes...

[cobito]

@deeiivid:

I've tried it with lxde's file manager and also with transmission and it was a mess… I'm going to run knoppix and see how it goes...

It's strange. Anyway, in the case of transmission, it's best that you run the daemon (or the graphical client) on the server and from your PC you run the remote client because if you run a graphical program over ssh and close the session, the program closes too.

[deeiivid]

@cobito:

It's strange. Anyway, in the case of transmission, the most advisable thing is that on the server you run the daemon (or the graphical client) and from your PC you run the remote client because if you run a graphical program via ssh and close the session, the program closes as well.

Yes, yes, I have Transmission with the daemon, I've only tried it to see the performance…
By the way, is there any way to "kill" the X?
By default in my case they turn on with the computer... I would like to change that.

Edit: solved. But now I find that it doesn't start programs like Transmission by default when I turn it on... it's not a very serious problem but okay.

[deeiivid]

I have a little problem. I don't know what I did but now I can't start X services remotely lakdsjaslkdjsld

This is what I get when I start:
_
Kromann-Hackintosh:~ kromann$ ssh kromann@192.168.1.24 -X
kromann@192.168.1.24's password:
Welcome to Ubuntu 12.10 (GNU/Linux 3.5.0-25-generic i686)

• Documentation: Official Ubuntu Documentation

Last login: Sun Feb 24 23:57:42 2013 from 192.168.1.69
/usr/bin/xauth: timeout in locking authority file /home/kromann/.Xauthority
kromann@kromann-server:~$
_

And if I try to start an X service:
_kromann@kromann-server:~$ sudo pcmanfm
[sudo] password for kromann:
X11 connection rejected because of wrong authentication.
Can't open viewer:
kromann@kromann-server:~$
_

It's only with X services... I don't know how to fix it.

Edit: I've already fixed it, here I explain everything in case you have the same problem.

[Yorus]

Thanks for sharing, the truth is that I have never tried to run anything from the X remotely and it all sounded like Chinese to me.

[cobito]

Running graphical applications with SSH is not usually very practical for me except when it comes to the file manager. Having all the mounted drives at hand and being able to copy, paste, delete... at cruising speed from anywhere is a pleasure.

For everything else: remote clients.

[Yorus]

Today your guide has been very useful for me, since the installation steps I have followed vary greatly from what I did the first time. In my case, I downloaded a file that I decompressed directly onto the SD card and when I started the Raspberry, it did a classic Debian Netinst style installation downloading almost everything from the internet and leaving me with a typical root user and a normal user at the end.

Now I have followed your guide and the only different step is that I have flashed the image onto the SD card through Linux.

By the way, I like the change on your page, the new fonts look great.

[cobito]

Well, here's another one with data corruption on the SD. I was updating the system when messages started appearing about problems with the file system. I rebooted but it wouldn't start up again. I put the card in a PC, ran an fsck and it had a lot of messed up i-nodes. I'll see if I can recover it and if not, format it.

I read somewhere that doing an overvolt fixes the problem. This is a real pain because now you have to go messing around with things that could fry the raspi. You have to be careful with backups. I hope I haven't lost my MySQL databases.

[Yorus]

I put a Panasonic SD class 6 4Gb in it and we'll see how long it lasts, because it has been on for several days but it is not working. I hope we don't have to fiddle with it much so that it doesn't cause more problems with the SD card.

[Yorus]

I already have the transmission running at full capacity, but I have a question about how to access the data from another computer. I couldn't set up NFS because of some package that I can't remember that isn't available. I did set up SAMBA, although that only works for the local network.

What I need is to be able to access it even if it's through SSH using the file browser (nemo, nautilus or whatever it is) and many times I find that I can't do certain things because the user is not root. How do you usually do it? Do you give permissions to the normal user in those folders including the one of the web server? Or on the contrary do you create a real root user? Sometimes I get confused with this, and it's also not clear to me if it's better to give permissions to the external disk through fstab or giving permissions to the folder in which it is mounted, since I get confused when touching things and in the end I don't know which one makes it work well.

[cobito]

Section 7.2 of the guide explains how to start an FTP server whose root directory is the root of the Raspi, so in principle you could access all your storage devices in /media.

Section 10.1.3 explains how to manage files remotely using Dolphin (the KDE file manager) via SSH.

The owner of your downloaded files should be 'pi' so using the technique in section 10.1.3 you will be able to do whatever you want with them.

If you want to be able to manage files and folders whose owner is 'root','mysql' or any other different from 'pi' you will have to change the password of 'root' using the commands;
sudo -s
passwd root

Once you have done that, you can use the procedure in section 10.1.3 again using 'root' as the username and the password you have set.

I have not tried it, but I am sure that the file managers of other desktop environments also allow remote file management via SSH.

Another possibility is to follow the procedure in 10.1.2. The only drawback is that you will only be able to manage as 'pi' since for some reason it is not possible to launch X applications like 'root' from SSH.

[Yorus]

It's curious, yesterday from the PC that is inside the local network I couldn't create files/folders inside the transmission downloads folder with SSH (but with Samba), but right now through the internet I can. I don't know what would happen, but in both PCs I use the same Linux and they are configured almost the same way. Where I don't have permissions is in /var/www, although I imagine it's about giving them and that's it, but I don't know if it's convenient or it's better to do the operations as root activating it as you said. By the way and for those who are interested, from Cinnamon (file browser Nemo) you would access with a simple sftp://pi@x.x.x.x/.