Archive for settembre, 2010

Goodbye Debian!

posted by Viking
set 24

And I’m saying goodbye, not farewell!

By the way, I moved from Debian “Squeeze” ( 6.0 testing ) to CentOS 5.5 on Tomcat and, even with an older 2.6.18 kernel (compared to the newer 2.6.32 debian’s one) everything worked flawlessly: video, network card, audio.

I must admit that Tomcat is a little old, but the battery is still alive and it’s powerful enough for many of my daily task, like writing small programs, reading e-mails, surfing the web, doing some electronic projects, using office apps etc.

It is not that I don’t like Debian anymore. I was using a testing distribution and I had only minor issues, so I was quite happy with it.

Then Hyper-V came: a powerful virtualization service for Windows Server 2008 that is also able to run Linux as a guest OS. Great, but it only works with SLES or RHEL. You can obtain SLES for free but you will have only two month of updates without purchasing a subscripition with Novell. On the other hand, you can’t have RHEL for free, but you can have CentOS and upgrades for free, so I went for CentOS. I currently have a VM running CentOS with the Linux integrations services installed that works well.

I did a backup of all the data on Tomcat and installed CentOS on it. It works perfectly beside Windows XP on the another partition.

Recently, I have also installed CentOS on Nighthawk. I use it remotely via SSH or VNC.
I’m slowly getting accustomished to yum, even if sometimes I still type apt-get instead of yum… oh well.

However, my “goodbye” to Debian isn’t really true, because as of writing this post, this page is being served by apache running on a Debian 4.0 virtual machine according to the informations tophost gives me on the site’s control panel…

Bye

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Probably, this may works with other distributions, kernel versions and other systems, but I’m not going to do any further test.

Recently, a friend of mine asked me to install a new hard drive on his Sony Vaio laptop, because he ran out of free space on the original drive.

So after buying and installing a new 160GB drive, I began with the setup of Windows XP SP3. Anyway I left some free space for Linux.

Setting up Windows was quite easy, but setting up Linux, was a real nightmare.

I tried 4 differents x86 Ubuntu’s CDs (8.04 live, 8.10 live & alternate, 9.04 alternate). They all had the same problem: kernel hanged during startup. The strange thing about that was that by pressing a key (any key), kernel startup process moved forward of a single step, and, keypress after keypress, after 10 or more minutes, the OS was completely loaded!

I tried with OpenSuSE 11.1 live CD. There were less problems during startup, but the matter still remained the same: the OS required several keypresses to boot. After installing to disk, nothing changed.

Now, I’m not an expert, but thinking about that, I supposed there was a problem with interrupts or system clock or both, so after looking for solutions on Google, I found someone writing about the boot parameter “clocksource”.

To know clocksources available on my system, I wrote:

cat /sys/devices/system/clocksource/clocksource0/available_clocksource

on a terminal, and got:

tsc acpi_pm jiffies

Firstly I tried adding “clocksource=acpi_pm” in /boot/grub/menu.lst but, at the following boot, nothing changed.

Then I tried with “clocksource=jiffies“: that actually works!

The system boot up quite rapidly and without the need of any keypress.

Hope this article could help someone who is hitting a wall with his head trying to install Linux on this laptop.

Bye

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During the days of Saturday and Sunday, September 11 and 12 2010 respectively, on the Italian Air Force (Aeronautica Militare Italiana) base of Rivolto (UD), have taken place the celebrations for the 50th anniversary of the “313° gruppo addestramento acrobatico” (313th acrobatic training group), popularly known as “Pattuglia Acrobatica Nazionale” or PAN (national acrobatic team) and also known as “Frecce tricolori” (tricolor arrows).

Celebrations consisted of a two days long airshow. Actually, all the displays of saturday have been performed also on sunday. Indeed the Red Arrows was the only team missing on saturday.

Because of the downturn in the economic course that led to cuts in funding for defense, solo displays were quite few and limited only to Italian aircrafts:

  • Alenia Aermacchi MB-339CD, the “Charlie-Delta”, that stands for “Completamente Digitale” (completely digital) in reference to its glass cockpit. The display was performed by an aircraft and a pilot both from the “Reparto Sperimentale Volo” or RSV (experimental flight department) located in Pratica di Mare (Rome);
  • Alenia/Embraer AMX “Ghibli”, also from the RSV. I believe it was an ACOL, “Aggiornamento Capacità Operative e Logistiche” (operational and logistic capabilities upgrade), but I’m not sure;
  • Panavia (PA-200) Tornado IDS, the InterDiction and Strike version, always from the RSV;
  • Alenia Aermacchi M-346 “Master”, preproduction series vehicle, from Alenia Aermacchi;
  • Eurofighter EF-2000 “Typhoon”, always from the RSV.

No helicopter displays were performed, excluding the straight flight with the flag of an Agusta-Bell AB-212.

The static display was also limited to italian aircrafts only. Aircrafts were the same of the solo displays with the addition of a McDonnell Douglas AV-8B+ “Harrier II” Plus of the Marina Militare Italiana (Italian Navy), and a pair of General Dynamics F-16A ADF “Fighting Falcon”s from the 37° Stormo (37th Fighter Wing) located in Birgi (Trapani).
Static display also consisted of a Breda-Nardi NH-500, an Agusta HH-3F “Pelican” and a NHIndustries NH-90 helicopters.
The Selenia Spada SAM system was also shown on the static display as well as the historical jets of the various Italian acrobatic teams that are usually present on the base.

There were 8 acrobatic team (7 on Saturday):

  1. Bialo-Czerwone Iskry (“White-and-Red Sparks”) Polish team flying the PZL TS-11 “Iskra” (Polish for “spark”);
  2. Krila Oluje (“Wings of Storm”) Croatian team flying the Pilatus PC-9;
  3. Royal Jordanian Falcons team flying the Extra 300S;
  4. Patrulla Aguila Spanish team flying the CASA C-101 “Aviojet”;
  5. Patrouille Suisse team flying the Northrop F-5E “Tiger II”;
  6. Patrouille de France team flying the Dassault-Dornier Alpha Jet;
  7. (only on Sunday) Red Arrows British team flying the BAe Hawk T1A;
  8. Frecce Tricolori team flying the Aermacchi MB-339A/PAN.

Of course it was a great show, but being a “veteran” (I was there also for the 45th and 40th anniversary), means that I’ve made a comparison between the three airshows and the result are not excellents.
The 40th and 45th anniversary were both better. There were a lot of aircrafts from other countries, both flying and on static display.
The only news, at least for me, this years, were the Bialo-Czerwone Iskry and the Krila Oluje teams, because I’ve already seen everything else. If it’s true that many people haven’t already seen so many (or even any) military aircraft, it’s also true that many people follow this kind of shows by years.
Last year I was in Zeltweg for the AirPower 09 and It was really terrific! Troups deployment and hostages rescue demonstrations, “Blackhawk”s demonstrating their heavy lift capabilities, “Typhoon”s simulating a QRA mission with an “Hercules”, warbirds, historical airliners… the AirPower 09 really redefined my standards (beside, of course, of commercial air shows, like those of Le Bourget or Farnborough).

Another issue of the show was the time the show started. At 11 o’clock am (or 0900z if you prefer, and remember the daylight saving time) it’s too late! It’s awful to take pictures at 6 o’clock pm (1600z), almost at sunset, with a runway heading of about 240 degrees.

Nevertheless, considering the downturn in the economic course, I cannot complain too much. I hope anyway that the show for the 55th will be far better that this.

Bye

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set 8

This is a post taken from an old unused blog of mine. Many things have changed, but this article could be useful for distributions that still use the “classical” ( /dev/sda1 or /dev/hda1 ) way to refer to mass storage devices.

Having some spare time, I decided do some jobs on Mirage.
Apart from Solaris 9 that is unused by months on the Samsung 20GB IDE drive, I decided to reinstall Debian 4.0 on the Fujitsu 18GB SCSI drive that was initially placed inside the Sun 599 box.
Version 4.0 is the last one that allow installing a working dektop environment. Version 5.0 with the “new” 2.6.26 kernel doesn’t correctly start X.org, while Debian 4.0 works flawlessly.
Just to try something new, I decided to go for XFCE as default desktop environment instead of Gnome.
Installation was perfect, but at the first reboot, the system halted on the message:

Begin: mounting root file system

Obviously, there are some problems in mouting /, /boot, /usr and other filesystems…
Pressing

[STOP]+[A]

take me to the OpenBoot prompt where using

reset-all

I restart the system, this time giving more attention to the kernel messages.
During boot, kernel finds the Samsung IDE drive, the two 9GB IBM SCSI drives inside the Sun 599, the Plextor SCSI CD drive and, finally, the Fujitsu SCSI drive.
Ok, so, if the two IBM drives are /dev/sda and /dev/sdb respectively and the Plextor CD drive is /dev/sdc, then the Fujitsu drive must be /dev/sdd.

Obviously the system hangs on the same message, as before.
Once started BusyBox, the emergency shell

mkdir temp

followed by

mount /dev/sdd1 /temp

Some warnings, but it mount the file system. With

ls /temp

I can read the files in /boot

 An immediate check to the silo.conf file shows me

root=/dev/sdc4

So, in a moment

vi /temp/silo.conf

the “wrong” parameter is modified.

At the next boot… the system hangs always on the same message.

Uhm… probably (ehm, that means, “for sure”) I mounted the file system read-only from BusyBox.
Looking at the file, I actually haven’t modified it.

At the next boot, at the SILO prompt I type

help

and SILO tells me that I can define a root device using

root=/dev/$device

So I try

linux root=/dev/sdd4

and finally boot goes on, even if it stops for another less important reason.

The next question is easy to solve. It simply try to mount /dev/sdc4 as /.

mkdir temp
mount /dev/sdd4 /temp
vi /temp/etc/fstab

Just the time of changing every reference of /dev/sdc to /dev/sdd and rebooting and…
Voilà! Everything goes right and within a minute I’m able to login in gdm.

Okay… and now there is a problem bigger than a house.
The CD-ROM drive IS NOT /dev/sdc.

And so, what?

What the Hell is “stealing” a SCSI drive designation?

… SUSPENCE …

 

The “thief” is a 128MB USB flash drive, to which the kernel assigns the designation /dev/sda.
Obiviously, removing that drive means that the system hangs on finding the root file system…
Changing silo.conf and /etc/fstab to use the original /dev/sdc  make the system bootable without the USB drive inserted, but of course with the drive inserted the system is unable to boot.

The title of this article came from a message the Debian installer wrtites at the end of the process:
“The Silo bootloader results installed. The system should now be bootable.”

[UPDATE - PROBLEM SOLVED]

After asking some friends and doing some search I’ve found many interesting things (like how useful udev can be)… that haven’t helped me figuring out how to solve this problem.
The BIG idea come from a friend’s laptop on which I recently installed OpenSUSE 11.1. This Linux distribution uniquely identify a disk using an id. To access a mass storage device, instead of using the classical

/dev/sdxn

where x is the letter used to identify the physical disk device and n is the number identifying the partition, uses

/dev/disk/by-id/scsi-SFUJITSU_MAN3184MC_JADDAJADDAJADDA-partn

where JADDAJADDAJADDA is the device serial number and n is always the partition number.
This way to identify the various devices has been introduced in kernel 2.6 and newer.

Modifying silo.conf and /etc/fstab accordingly Mirage is now bootable even with more USB devices attached.
A minor “collateral damage” is that the system disk can be designated in various different ways depending on the number of external disks connected, but until now this has caused no problems.

Bye

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