Convalesco

Έχω έναν φορητό υπολογιστή Fujitsu Siemens (AMILO). Τα specs δεν τα γνωρίζω καλά καλά, αλλά υπολογίζω 1.5 Ghz / 512 MB Ram / 40 GB HD. Το CDRom είναι χαλασμένο. Θέλει καρφίτσα, τσιμπιδάκι για να σφηνώσει έτσι ώστε να μην αναπηδά το CD. Το συγκεκριμένο laptop έχει δυνατότητα PXE boot. Συγκεκριμένα το PXE-2 της intel.

Οπότε αποφάσισα να χρησιμοποιήσω το Dnsmasq έτσι ώστε να κάνει boot σε Ubuntu το μηχάνημα μέσω δικτύου. Το πρώτο που πρέπει να κάνω είναι το setup του server.

Κάνω edit το dnsmasq.conf. Η διανομή του server είναι Gentoo GNU/Linux. Οι ρυθμίσεις στην ουσία είναι για Gentoo αλλά με ευκολία μπορούν να λειτουργήσουν σε όλες τις διανομές Linux.

# mkdir /mnt/tftp ; cd /mnt/tftp

# screen lftp -c “open http://archive.ubuntu.com/ubuntu/dists/hardy/main/installer-i386/current/images/netboot/; mirror”

#ln -s /mnt/tftp/pxelinux.cfg/default /mnt/tftp/pxelinux.cfg/000AE42EA642

# cat /etc/dnsmasq.conf
dhcp-boot=pxelinux.0,gentoo-server,192.168.3.45 #boot image, server και ip του server
enable-tftp # Λέμε στο dnsmasq να κάνει start τον tftp demon. Αλλιώς θέλουμε κάτι σαν το tftp-hpa.
tftp-root=/mnt/tftp #Θέτουμε το root directory του TFTP server

Αφού κάνουμε start το dnsmasq, χρησιμοποιούμε το netstat ή το lsof για να δούμε αν οι υπηρεσίες που μας ενδιαφέρουν λειτουργούν κανονικά:

egasus tftp # lsof -i|grep -i dns

# lsof -i|grep -i dns
dnsmasq 23683 nobody 5u IPv4 137982 UDP *:bootps
dnsmasq 23683 nobody 6u IPv4 137987 UDP *:domain
dnsmasq 23683 nobody 7u IPv4 137988 TCP *:domain (LISTEN)
dnsmasq 23683 nobody 8u IPv6 137989 UDP *:domain
dnsmasq 23683 nobody 9u IPv6 137990 TCP *:domain (LISTEN)
dnsmasq 23683 nobody 10u IPv4 137991 UDP *:tftp

ή

# netstat -lu|grep tftp
udp 0 0 *:tftp *:*

Στο παραπάνω παράδειγμα κάνω χρήση της εντολής “ln”. Το αρχείο default κάνει link στην MAC Address του client που θέλουμε να κάνει boot. Πως την βρίσκουμε; Κάνοντας ένα ping στο target και χρησιμοποιώντας την εντολή “arp -a” σαν root!
Προσοχή, στο ln -s, το mac address που βάζουμε ως link είναι χωρίς τα “:”. Κάπως έτσι:

pegasus ~ # ping -c 1 192.168.0.1
PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data.
64 bytes from 192.168.0.1: icmp_seq=1 ttl=64 time=0.451 ms

— 192.168.0.1 ping statistics —
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.451/0.451/0.451/0.000 ms
pegasus ~ # arp -a
router (192.168.0.1) at 00:1d:7e:b4:78:da [ether] on eth0
pegasus ~ # ln -s /mnt/tftp/pxelinux.cfg/default /mnt/tftp/pxelinux.cfg/001d7eb478da

Έπειτα ανοίγουμε τον υπολογιστή που θέλουμε να εγκαταστήσουμε το σύστημα και κάνουμε boot κι απλά ακολουθούμε τις οδηγίες στην οθόνη!

EDIT: Εάν για κάποιο λόγο κολλάει η εγκατάσταση στο “Release” και δεν σας βγάζει πληροφορίες για τα πακέτα που κατεβάζει, αλλάξτε το mirror! Το Ελληνικό δεν είναι ενημερωμένο συνήθως, καλύτερα δοκιμάστε το Ιταλικό “it.archives.ubuntu.com”.

In today’s society, where an individual is expected to produce and achieve a large number of things, time optimisation is crucial. The last one and a half month, I’m trying to get fit and lose pounds in order to start the Snowboarding season with no hassles. I’m at least 5 kilos above my optimal weight and this could cause me serious problems when snowboard falling.

Snowboard apart, it is a matter of self respect and esteem, taking care of your body.

However, every day, something happens and I have to postpone the gym. This schedule wont get me anywhere near where I want to be. Hence I need to fined the strength and say no to friends and parents when I have to and press myself to go the gym even when I’m feeling tired.

I had my first Tennis lesson the other day. It was quite interesting. I think I’m quite good at hitting the ball forth-hand but back-hand is not difficult either. I guess, it’s totally different when you try to hit the ball on the move. Especially the back-hand is a move I must get used to it. We didn’t practise enough to the service yet. It seems to be the toughest move.

I like Tennis very much, the problem is that in our first lessons, the lessons are technical. It’s natural I guess, how can you catch the ball on the fly when you can’t catch it steady? So, the practise comes to an end and I’m feeling not tired, at all.

I need something that will make me sweat! This wont happen in the gym either though. I go to the gym only because I have to, I dislike it as a default exercise. I think I will rejoin the doJo. I like Tae Kwon Do, although our sensei, likes to do much more physical exercise in practise, I like it. The practise length is about two hours. The first forty minutes are all exercises and running along with the last twenty, for relaxing the muscles.

Now, related to snowboarding, Tae Kwon Do is a very good exercise because it tries to make your body flexible. Flexibility is crucial to avoid injuries in snowboard. You don’t have a clue about what position will you have to take, the next time you fall.

The problem actually is that once, I was falling all day long on the track going slowly. Now, I go much faster, I try to master ground tricks on the run, I do some low jumps. I rarely fall and I’m able to do every track I’ve seen, but when I fall, it hurts! Last year I had a very bad crash. The stance didn’t help much and after riding the most tedious track on Falakro mountain, I just stood up on the snowboard at full speed, straining my knees, which is a silly mistake for an average snowboarder. The crash that I had when the nose of the board stuck at full speed and my forehead hit the ground, was memorable! A few people stopped and asked me if I remembered the day, the place. I felt dizzy and stopped snowboarding. It was the first time I stopped because of a crash. I searched for the doctor and he said that I might have lost the entire season with a second crash like that, so it was better to get some rest and a nice cup of tea.

So, in order to get fit once again, I need some serious exercise. In order to do some serious exercise, which means Tae Kwon Do, three times per week, I need a strict schedule. In order to make that strict schedule actually useful I need to optimise my time at work and home. I have a two or three hobbies, 1 language to learn and a very much time-spending job to do. I’m still struggling to find the proper way to put these things together without issues. But fitness is of great importance for my temper, my appearance and my endurance at work. I notice that I get tired very easily lately. It’s not the sleep, I sleep very much compared to last year, when I was serving the army. It’s a matter of physical exercise converging to zero.

Me and my friends like snowboarding. So considering all the hype and my hobby, which is the www and operating systems such as Linux and MacOSX, I decided to make a website that will deal with snowboard. I created the website boarders.gr using a CMS. The visitors are not much, of course I didn’t publish the website to popular websites which I had easy access, because I know the admin, or even my blog which has a small amount of regulars. So I decided to use Sandvox, then I downloaded Rapidweaver and then I tried to create something using iWeb. The problem is that I don’t want to give money to the MobileMe thing. I tried the trial version and didn’t convince me at all. I own the domain name already and I have some free space on dreamhost. So iWeb is tricky if used without MobileMe. However, which one is the best for what I want to do? I tried them all!

Rapidweaver is a great tool for an average user which knows at least how a website looks like from a structured perspective. It’s a solid piece of software, with no bugs or just a few (I have not found any) and a decent community. The developers seem to be much user friendly and you probably get a quick reply. It’s quite for personal website building, it uses Haloscan to manage user blog comments and has many themes for a single package. All these come at a high, in my personal opinion, price of 79 $.

Sandvox is the easier, most user friendly application for web development. It lacks of some features and the look and feel of Rapidweaver. It’s much more easy to understand at a glance, compared to RW, because it has the standard preview editing mode. So you actually create, delete, edit on the website. It has enough themes to suit the average user needs. It’s blog RSS support was broken at 1.3 version. Now Sandvox is at 1.5 version and seems to have get over these bugs. However… It’s very buggy. I’d say that it was not ready for an official yet. I’ve been using Sandvox since it was a ‘beta’. Then I bought it. I still use it for personal websites that I quickly like to setup on my linux server, but even for a blog engine or a small personal website, I prefer wordpress by far. However, it fails many times when you switch themes and it fails to handle images correctly when you remote them and add them again. Same goes for pagelets. It’s not stable, period. I’ve lost 4 hours of work because I forgot to save and it crashed. I know that it says in the website that it has auto-save features in preview mode, but that’s nonsense. I just lost everything.

The iWeb platform is not bug free, but it’s in the 2.0 version and seems to be pretty stable. I worked a lot with iWork Pages and I was able to use iWeb promptly because of the similarities. The image editing is the same, the themes are much more beautiful than Rapidweavers or Sandvox’s. The interesting thing with iWeb, except it’s superior looks, is that it let’s you place image everywhere and it acts like a Pages documents. you can do whatever you have in mind. I find iWeb to be much more flexible in this area, compared to the other two.

The problem with iWeb is that, you need MobileMe in order to work for you flawlessly. The 79$ per year subscription is a bit too much for me. I already pay for webhosting at DreamHost and I own the domain name already. Plus, what if my users ask me a forum? From what I know I don’t have PHP or MySQL support and if I do, I can’t image what would be the price for it. It’s a bit of an insult to Apple users the MobileMe policy.

I still have to decide what to do, I would love to be able to use iWeb, but the MobileMe trial is about to expire and I will cancel the subscription because I consider the price high, plus the fact that it’s not extensible at all. Same goes of course for sandvox and rapidweaver but there, I will be able to create a link and put a php-forum on DreamHost like www.mywebsite.com/forum.

Anyway, if you are looking for a website builder at this point: You can buy the MobileMe bundle and use iWeb or use Rapidweaver if you already pay for web hosting. Rapidweaver is not cheap but it’s mature and it will not blow in your face like Sandvox.

Οι Martin Vuagnoux και Sylvain Pasini απόδειξαν, με μια πρακτική εφαρμογή, πως μπορούμε να κάνουμε μια επίθεση στα ηλεκτρομαγνητικά κύματα που εκπέμπουν τα καινούρια πληκτρολόγια του εμπορίου. Τα περισσότερα USB πληκτρολόγια, που είναι αυτά τελευταίας τεχνολογίας, έχουν αυτό το “πρόβλημα”¹.

Το παραπάνω πείραμα δεν είναι κάτι καινούριο στον κόσμο της τεχνολογίας. Η ιδέα είναι πολύ παλιά, όμως, ακόμη και τώρα, θυμίζει κάτι από Mission Impossible

1. Κάτι παρόμοιο, γίνεται και με την ακτινοβολία από τις κάρτες RFID για κλοπή στοιχείων [↩]

When I was a fanatic GNU/Linux user, using a Gentoo desktop all day long for every single task, I was addicted at readings like BoF and affiliate journals or jokes. Talking to many people, who in the hearing of “Linux” reacted with admiration over me, I was confident that I’m way above the average computer user level.

The most stupid thing I can remember is, working via secure shell and shutting down the service. I can’t remember if I shut down the demon after a new configuration of the ssh server, locking myself and everyone else outside(!) of the server, or was it an iptables rule that I didn’t test? Can’t remember right now.

A couple of days ago a friend asked me to move his server to my office, because he needed a 24/7 static ip, stable internet connection. So I said okay. Once we began to install the HP server, running Win2K server, a VPN network and other applications, we connected everything, the USB UPS, the Ethernet cable and the server was accessible from the office LAN, but not the internet. I insisted to my friend that I can manage to make this thing work. I took a quick look to the hardware configuration, the ethernet cable was there, the USB UPS was connected, everything looked fine.

I lost like 5 hours to make the damn thing work with the current configuration. Switched 2 ADSL+2 routers, I spend 100 € and then I called my friend and told him to call the technician who configured the machine initially, Stelios. He is one of the leading members of DWN and one of the few people I know in my town that are far better than with UNIX machines. I know many tech people here, because the city is small and at the office I call support for hardware or software level (Windows) issues often. I know many pro technician that call me and ask me my help in the rare occasions that they need a UNIX server. Anyway, I called Stelios with the attitude of the knowledgeable guy, talking to him about the router’s problem with the PPTP protocol, the Firewall configuration and other fancy words. Deep inside I wanted to let him know that “Hey Dude, I’m capable! I can do UNIX and this Windows shit are easy for me!!!“. After yelling overconfident for 5 minutes straight, he asked me about the network configuration, because the computer had 2 NIC’s. I said, yes, the iLog and the regular NIC. He said “No there is another, PCI Ethernet which I installed”. I took a careful look at the computer and the following conversation took place:

Me: “No man, there’s just a USB PCI card that we plugged the USB UPS and nothing else, I’m sure, I’m looking at it”

Stelios: “No, I can’t be wrong. I configured that computer myself and there’s an ethernet NIC on the PCI interface, so it has to be there!”

Me: “No there’s just a USB plug nothing more, I’m telling you that the UPS is plugged on it!”

Stelios: “Excuse me, the UPS is plugged on a PCI USB card???”

Me: “Yes”

Stelios: “Who did the set up the computer, did you?”

Me (n an overconfident and self approving mood): “Yes, I did”

Stelios: “Can you please unplug the USB from the Ethernet port now?”

Me: “What are you talking about?”

Stelios: “I don’t know how you did it, but I’m 99% positive that you plugged the USB UPS on the Ethernet card, because that computer 2 USB ports in the front + the fact that I had plugged the UPS to the keyboard’s USB originally.”

Me (Feeling like a total idiot while accepting the truth, the port was a f*cking ETHERNET!!!): “Oh my God!!!”

Stelios: “You got the point, how the f*ck did you do that? It’s probably the most stupid thing I’ve ever heard by phone”

Me (With the ego crashed down and a will to continue the conversation converging exponentially to 0): “Hmm, yes, well probably I didn’t take a careful look at it, I just plugged the USB PCI and…”

Stelios: “Yeah yeah, okay. There you go, you should be all set now. The 2nd Ethernet has just a few ports open to offer services via Internet. The Firewall is specifically configured to do that on that NIC. So you should just plug an ethernet cable from that NIC to the router and you should be fine.”

Me: “Okay, thank you”

Stelios: “You’re welcome, see you.”

The phone call ended a bit brutally. I made so many changes to the WindowsNT server’s firewall that Stelios had to come to the office and fix the damn thing by himself. I was on a business trip so, I was not there to face him. This is by far the most stupid thing I’ve ever did with a computer related configuration. After using almost daily, 3 operating systems (MacOSX, Linux & Windows), after configuration the MS-DOS applications that most paid tech savvy people who passed from my office failed (DeFacto, Bar Code printer and now I’m dealing with a professional DataCorp bar code printer that - for now - doesn’t work as it should), after being an operator in Grnet’s #Linuxhelp and helping some (few probably) people with basic Gentoo / Linux configurations, after posting solutions in many, many forums, I did something unimaginably stupid just like that.

So, it’s better to hold our horses when why try to prove that we know, time will tell.

If you are really good at something and if you are not, hey it’s not a big deal, just think that you have enough to be happy with

Λοιπόν, αν θέλετε να σπάσετε το iPod Toucuh 2.1 διαβάστε εδώ το post του Παναγιώτη, κι εδώ το post από το iClariffied!!!

ps. Το QuckPwn κάνει το jailbreak πάρα πολύ εύκολο για όλους τους χρήστες!

Αφού κάνετε όλα τα παραπάνω βάλτε και Ελληνικά στο iPod Touch! Τρομερό επίτευγμα από τα παιδιά του myphone.gr!

Σήμερα πήγα στην ΔΕΗ Δράμας, για μια αλλαγή επωνυμίας. Παραλίγο να μαλώσω με τον υπάλληλο που με εξυπηρετούσε. Μου ζήτησε ένα χαρτί που να αποδεικνύει ότι μπορώ να υπογράψω για την εταιρία, στης οποία το όνομα θα έρχεται ο καινούριος λογαριασμός της ΔΕΗ.

Τέλος πάντων, του έδωσα το καταστατικό της εταιρίας, μια φωτοτυπία, την οποία αφού κοίταξε για δύο λεπτά αρνήθηκε να δεχτεί:

“Θέλω μια υπεύθυνη δήλωση ότι μπορείς να υπογράψεις για την εταιρία.” - Του εξήγησα το προφανές, ότι είμαι ένας από τους δύο μετόχους κι ότι φυσικά και μπορούσα να υπογράψω. Όχι μου ζήτησε μια βεβαίωση από τα ΚΕΠ την οποία θα υπογράψω εγώ στην οποία θα δηλώνω ότι μπορώ να υπογράψω για την εταιρία. Αφού τον ξαναρώτησα γιατί ακριβώς δεν γίνεται η “δουλειά” με το καταστατικό, παραλίγο ν μαλώσουμε… Με άρχισε στα γνωστά σε πολλούς: “Ακούς τι σου λέω εγώ τώρα…” κτλ. Λόγο της ηλικίας του, ο άνθρωπος είναι έτοιμος για σύνταξη, δεν επέμενα και πολύ παραπάνω. Άλλωστε κι αύριο μέρα είναι, θα πάω στα ΚΕΠ…

Δεν μπορώ να καταλάβω από σκατά προέρχεται αυτός ο αρνητισμός που σου βγάζουν αυτοί οι άνθρωποι του δημοσίου. Δεν μπορώ να καταλάβω γιατί είναι τόσο αρνητικοί. Αν ήταν ένας υπάλληλος, θα έλεγα “δεν πειράζει” αλλά στην ΔΕΗ, είναι 2 ή 3 που είναι αρνητικοί με τους αγνώστους από το καλημέρα…

έλεος..