Ubuntu Linux in Computer Labs
The computer labs generally offer Mac OS, Windows and Ubuntu Linux on
the desktop computers. For selecting an operating system, the user must
reboot the corresponding computer, and select the preferred OS from a
menu. In the computerlab in Askja, (The Natural Sciences House) users
can only choose between Windows and Ubuntu Linux. The user can turn the
computer off and then turn it on again and then wait approximately 30
seconds for the menu.
0. Windows (Default)
1. Ubuntu Linux LTSP terminal.
2. Ubuntu Linux Full OS.
Both options 1 and 2 are diskless versions of the OS. Option 2 gives
much better performance and user experience and runs all applications on
the users computer. Option 1. gives a much broader selection of
software, but runs all applications on the server, which may degrade
performance if many users are using the server.
Currently the version is Ubuntu 10.04 also named Lucid Lynx. There is a
wealth of languages and desktop environments to choose from.
Before the users log in, they can choose the desktop environment by
selecting session type. Most popular are KDE and Gnome. Interface
language can also be selected before login. There are about a hundred to
choose from.
Computing Services provides each user with a personal username and
password. This gives access to a wide range of services. All normal
access, including printing, networking and of course access to the
university computing cluster by the hostname jotunn.rhi.hi.is .
A personal diskspace belongs to the username. The diskspace is hosted on
a a shared storage, that each user acesses either through the CIFS
protocol commonly known as Samba. This is also known as a Windows share.
Users can also access their personal diskspace through NFS. When
mounting a diskspace manually using a Windows Share, the hostname is
heima.rhi.hi.is .
When a user logs into the computer lab, he or she is automatically
logged into the personal diskspace and it looks like a local diskspace,
but in fact it is hosted remotely on a fileserver.
The user information is stored in an LDAP directory server, that serves
the whole campus. So if a user changes the password at one place, the
change takes immediate effect on the whole campus.
The username also has a corresponding email address, with a
corresponding email account. The login for the email is
https://postur.hi.is/ . Mail can also be fetched using a mail client. We
recommend Mozilla Thunderbird. For manully setting up the mail, the user
needs to know that the hostnames are smtp.hi.is and imap.hi.is .
One of the services is a homepage at http://notendur.hi.is/annaj/
for the username annaj. The content of this homepage is located in
a folder named .public_html . The most popular method to put content
into this folder, is by mounting it as a Samba drive and then moving
files into the folder. Guru users prefer to use the command line to do
the same thing.
cp skra.txt ~/.public_html
All internet access is open, but a firewall protects known ports from
attacks. The hostname of the LTSP server is bestla.rhi.hi.is . When
running Ubuntu Linux LTSP terminal, everything is in fact running on
that server and the net traffic is more constrained by the servers
sophisticated firewall.
For uploading and downloading data, the user can use SSH anywhere in the
world. Preferably the University computing cluster can be used. The
hostname is jotunn.rhi.hi.is . If a user has a folder with files named
2011-a-course , and this user can write to a shared drive
at /home/svaedi then the guru user would issue a command like so:
scp -r 2011-a-course/ annaj@jotunn.rhi.hi.is:/home/svaedi/
Also available for users, is the multiuser server Katla with hostname
katla.rhi.hi.is . Users can login there and check mail using mutt,
(mostly used by gurus), print, edit documents in a shell etc.
The print command to print the postscript file skyrsla.ps on printer in
Askja computerlab is:
lpr -P nfprint00 skyrsla.ps
or
lp -d nfprint00 skyrsla.ps

