Table of Contents

Ottavinareale (and Andromeda)

Rules to access and dual quad core

www.industrialcomputersystems.com_images3_6013pt.jpg 8 core (no hyperthreading) 8 core (with hyperthreading)

ottavinareale and andromeda are machines used for both research and teaching. There are many users currently performing different kinds of experiments. We therefore set up an informal reservation mechanism, that works as follows.

Please read carefully the motd when you log in to ottavina. The message is automatically appended onto your login screen (in ASCII mode). If you miss the message, you can anytime read it using a simple command such as:

more /etc/motd

In case there is a message stating the machine is reserved at the time you login please logout immediately and try to login again only after the reservation period is gone.

Users not respecting the registrations will get an advice and, in case of multiple violations, will loose the access to the machine.

Whenever accessing the machine, any message redirected to your terminal by accounts marcod, aldinuc, torquati, pascucci, buono should be immediately taken into account (these accounts represent the “admin” accounts).

Clean up before logout

Attention When you logout, please don't leave any process running on the machine, nor busy resources (e.g. SysV sems). We suggest you to use a

kill -9 -1

to stop all your process running and logout immediately (the command kills abruptly all the processes of the user, including the ssh one).

How can I verify the current utilization of the machine ?

There are several classic Linux commands that can be used to figure out machine utilization:

Please look at the online manual of these commands for more details (e.g man top at the shell prompt)

How can I test reservations on the machine from outside

In order to check active reservations, as well any other message that would appear at the login, you can run from any shell (Linux, Posix, Windows with some SSH support installed) the command

ssh cat /etc/motd

This performs a remote login and executes the cat command only. To avoid having the passwd asked, please consider to install you ~/.ssh/ key (from the accessing machine) into your ~/.ssh/authorized_keys file. Be sure when you cut&paste the public key you don't leave extra carriage returns in the authorized_keys copy (the key must be on a single line) and that the auhorized_keys file has right permissions (rw for the user and r only for groups and other users).

Ottavinareale usage

The accounts assigned on ottavinareale may be used without reservation any time, provided when you log in there is no “Active reservation” message in the /etc/motd (the text (file) you see right before shell prompt on the terminal. The contents of the message may be seen any time with a cat /etc/motd command from the shell prompt, or with a ssh cat /etc/motd from any other (Unix/Linux/BSD) machine shell prompt). Code development, debugging and initial tuning may took place on the unreserved machine. The reservation mechanism is only recommended to be sure you'll take time with no other users on the machine for the final tests, those needed to generate the plots included in the final project report. Remember that I suggested you to prepare scripts to be able to run tests offline, in such a way you may also use nightime reservations.

Installed software

Usually, additional software available on ottavinareale is placed under


Have a look at the directory contents (directory and bin subdirectory) to see what additional software is available.

At the moment being, the following packages are available under /usr/local:

  1. mpich (version 1.1 and 1.2, including shmem version)
  2. FastFlow (version 1.1.0, not including distributed node extensions, nor gatherall collector policies)
  3. jdk 1.6 (different versions) and 1.7
  4. SkeTo (Skeleton library by Tokio Univ.)
  5. gcc 4.4 (providing tasks under OpenMP)
  6. cilk C (cilkc in /usr/bin/local)
  7. Skandium (1.0b2)
  8. SkePu (to be used for CPU only, ottavina has no GPU at the moment)

This pre-installed software may be used simply including proper directories in the $PATH, or passing them to gcc/c++ compiler with -I and -L/-l flags.

Access from outside Dept. of Computer Science

You can access the machine from anywhere on the Internet with a command such as


and you can move files to and from your home directory on ottavina with a

scp localfilename
scp .

In order to keep synchronized files on your local machine (e.g. the Linux laptop) with the remote machine, you can use an rsync command

rsync -avz DirWithoutTrailingSlash 

synchronizes files on the local directory with those in the DirWithourTralingSlash under your home directory under ottavinareale. Only differences are sent through the network, therefore the process is quite efficient (much more that scp-ing the whole directory, as an example). Please have a look at the rsync manual before using the command. Also take into account there is no primitive rsync under Windows (while it is normally present in both Linux and Mac OS X).

In case you want to execute programs with a graphic output, please consider using the -X option of ssh:

ssh -X

redirecting any X window to your local X server (therefore you should have an X server running on the local machine. This is normal when using Mac OS X or Linux, but it should be set up explicitly when using windows). Take into account that X redirection takes time. Responsiveness of the redirected application could be significantly impaired.