I'm on Holiday

Today is my birthday, if someone want to send me a present, don't be afraid :P.

Finally I'm on holiday, (Friday was my last working day). If someone is asking where I am, the right answer is:

Somewhere in the "Milky Way".

See you on 13rd of August.

The sea through ...

The sea through ...
Originally uploaded by gutter.

Shadows on sand

Shadows on sand
Originally uploaded by gutter.

Boats

Boats
Originally uploaded by gutter.

Boats in front of "Scala dei Turchi"

Boats in front of "Scala dei Turchi"
Originally uploaded by gutter.

Scala dei Turchi

Scala dei Turchi
Originally uploaded by gutter.

The Glider: A Universal Hacker Emblem

Eric S. Raymond proposed a new emblem that should represent the entire hacker community.
The emblem was proposed in the October 2003, but I discovered it this morning 0_o.

The symbol represents a "glider", a particular pattern existing in the simulation "The game of life".

BTW, I think that this is not a bad idea :).

A modern hacker #2

A modern hacker #2
Originally uploaded by gutter.

A modern hacker #1

A modern hacker #1
Originally uploaded by gutter.

My GPG KEY ID

This is my GPG key :)

GPG KEY ID: 2E7779A0

Please use it.

Casera Cola spot

Tracy Chapman videos

Fast Car



Crossroads



Subcity (Live Taormina)

How to generate network load diagrams

Yesterday, someone asked me how I generated the network load diagrams used in the post "SSHFS performance test".

My original idea was to search for a ready to use software, but surfing the web I didn't found anything simple to install a quick to use. So i decided to write some bash lines to generate raw data and OpenOffice (oocalc) to draw the diagrams.

This is the script used to generate raw data:

#!/bin/bash

###################################
#
# Wed Jul 11 11:38:54 CEST 2007
#
# This script is used to generate
# network traffic statistics
#
# Author: Davide Restivo (xgutter@yahoo.it)
#
# Released under GPLv2
#
####################################

E_BAD_ARGS=65

# The default interface
INTF="eth0"

# Default output filename
TMP_FILE=`tempfile`
FILE_OUT="netmon-`basename $TMP_FILE`.out"

# Default delay measurement
TICK="1"

# Usage
function usage () {
echo "Please invoke this script with zero or three arguments."
echo ""
echo "Example:"
echo " $0 "
echo ""
echo "where:"
echo " defaults to eth0"
echo " is automatically generated"
echo " is equal to 1 second"
}

# Let's check command line arguments
if [ $# -eq 0 ]
then
:
elif [ $# -eq 3 ]
then
# Setting parameters
INTF=$1
FILE_OUT=$2
TICK=$3
else
usage
exit $E_BAD_ARGS
fi

################
##### MAIN #####
################
echo "Seconds - Byte sent - Byte received" >> $FILE_OUT

SECONDS_COUNTER="0"
while true;
do
INITIAL_BYTE_SENT=`ifconfig eth0 |grep bytes|cut -d":" -f3|cut -d" " -f1`
INITIAL_BYTE_RECEIVED=`ifconfig eth0 |grep bytes|cut -d":" -f2|cut -d" " -f1`

sleep $TICK

BYTE_SENT=$((`ifconfig eth0 |grep bytes|cut -d":" -f3|cut -d" " -f1` - $INITIAL_BYTE_SENT ))
BYTE_RECEIVED=$((`ifconfig eth0 |grep bytes|cut -d":" -f2|cut -d" " -f1` - $INITIAL_BYTE_RECEIVED ))

TEMP_SECONDS_COUNTER=$(($SECONDS_COUNTER + $TICK))
SECONDS_COUNTER=$TEMP_SECONDS_COUNTER
echo "$SECONDS_COUNTER $BYTE_SENT $BYTE_RECEIVED" >> $FILE_OUT
done

Antico proverbio cinese

Il saggio cinese dice:

Le case restano, i culi cascano...

Apache 2.0.59 (Commodore C64) 0_o

Today, while I'm reading some IT news, I've found a funny one ;).

Someone noticed, that an important e-shop is running its core business application on very old computers.

An extract from netcraft could clarify how old are these machines:

unknown Apache 2.0.59 (Oric Dragon32) 89.107.41.30
unknown Apache 2.0.59 (ZX Spectrum 48k (Rubber Keys)) 89.107.41.3
unknown Apache 2.0.59 (Commodore C64) 89.107.41.30
unknown Apache 2.0.59 (CBM PET) 89.107.41.30
unknown Apache 2.0.59 (MSX Toshiba HX-10) 89.107.41.30
unknown Apache 2.0.59 (Commodore C64) 89.107.41.30
unknown Apache 2.0.59 (ZX Spectrum 48k (Rubber Keys)) 89.107.41.30
unknown Apache 2.0.59 (CRAY) 89.107.41.30
unknown Apache 2.0.59 (ZX Spectrum 48k (Rubber Keys)) 89.107.41.30
unknown Apache 2.0.59 (MSX Toshiba HX-10) 89.107.41.30

One guy of ebuyer crew explains that some HTTP strings was modified in order to prevent some low level lamer attacks.

The mistery was unveiled ;)

SSHFS performance test

Some days ago, I made some tests on SSHFS.

Let's talk, for a moment, about SSHFS.

From SSHFS home page:

This is a filesystem client based on the SSH File Transfer Protocol. Since most SSH servers already support this protocol it is very easy to set up: i.e. on the server side there's nothing to do. On the client side mounting the filesystem is as easy as logging into the server with ssh.

The idea of sshfs was taken from the SSHFS filesystem distributed with LUFS, which I found very useful. There were some limitations of that codebase, so I rewrote it. Features of this implementation are:

* Based on FUSE (the best userspace filesystem framework for linux ;-)
* Multithreading: more than one request can be on it's way to the server
* Allowing large reads (max 64k)
* Caching directory contents

Basically, SSHFS is a FUSE (File System in User Space) module.

In order to install it on gentoo GNU/Linux:

# emerge -av sys-fs/sshfs-fuse

Let's mount a remote directory:

# sshfs user1@192.168.177.172:/home/user1 temp_dir

If you would umount the remote dir, you should use the command:

fusermount -u temp_dir

Uhm, amazing simple ;), but what about network performances?

The following diagrams figure out network performances:

The tests had performed on a 100MBit network with very low traffic.

"The Enterprise Incident" (TOS), data astrale 5027.3

Sarebbe illogico assumere che tutte le condizioni rimangano stabili.
-- Spock, "The Enterprise Incident" (TOS), data astrale 5027.3

Summer fruit

Summer fruit
Originally uploaded by gutter.

Gnam gnam :D

Sunday morning and just a little of relax ;)

I don't remember how much time ago I spent all the morning at home (and near home) with my sister here in my little town missed in Sicily.

If someone want to know where exactly is, I can provide latitude and longitude, so you can search it in "Google Maps".

This morning I'm trying to improve myself ;) what does it mean is very simple but not very clear :D.

I've got only a regret about this weekend.
I didn't make any photos. Yesterday I wanted to take some photos to the sea but I forgot my camera.

Doh!

This afternoon probably I will go around to take some photo ;).

I will show you how can be beautiful a little agricultural town without any technological involvement ;).

Some funny images

You can find other funny stuff at http://fun.drno.de/.

Difference between chattr and chmod

what's the difference between chattr and chmod?
SomeLamer: man chattr > 1; man chmod > 2; diff -u 1 2 | less
-- Seen on #linux on irc

Corporate organization chart

Thanks to rossy.

A week summary

Let's try to summarize this week.

Uhm, let's forfeit :S

Do Androids Dream of Electric Sheep?

Yesterday, I bought this book.



This is the Italian translation of the famous Philip Dick's novel "Do Androids Dream of Electric Sheep?".

I never read this novel, but I know that this book inspired the film "Blade Runner" (directed by Ridley Scott).

If someone is interested I could lend it (after I finished reading) ;).