Tux Love

iPhone into iSpy

Sun, 29 Aug 2010 18:15:10 +1300

The Electronic Frontier Foundation (EFF) are labelling Apple's latest patent application "traitorware" ...

While users were celebrating the new jailbreaking and unlocking exemptions, Apple was quietly preparing to apply for a patent on technology that, among other things, would allow Apple to identify and punish users who take advantage of those exemptions or otherwise tinker with their devices. This patent application does nothing short of providing a roadmap for how Apple can — and presumably will — spy on its customers and control the way its customers use Apple products.

Ostensibly designed to respond to the loss of a phone it will give them the ability to;

Take a picture of your face "without a flash, any noise, or any indication that a picture is being taken to prevent the current user from knowing he is being photographed".

Record your voice, whether or not you're even making a call.

Determine your individual heartbeat "signature"(!)

Monitor all internet activity and record "any communication packets that are served to the electronic device".

The EFF are calling it "downright creepy and invasive". "Spyware, and its new cousin traitorware, will hurt customers and companies alike — Apple should shelve this idea before it backfires on both it and its customers," they say.

The patent's here.

Time to upgrade : KDE 4.5

Tue, 24 Aug 2010 20:06:24 +1300

I've always been a sucker for the latest download, especially when it comes to KDE, so I was pleased to discover this multi-distro compendium of How to Install KDE 4.5 on MakeTechEasier. You'll find directions on how to upgrade Kubuntu, Mandriva, OpenSuse, Fedora, Slackware, Gentoo, PCLinuxOS and Linux Mint, so what are you waiting for?

And while the upgraded packages are downloading, check out this preview of what you'll find in this release.

Firefox : Awesome addons - GoogleSharing

Thu, 19 Aug 2010 21:40:22 +1300

Most people believe that Google is a search engine company. It's not. It's an advertising agency that just happens to own the world's most successful search engine, and every time you use that search engine, they learn a little more about you.

If you're like most internet users, Google knows more about you than you might be comfortable with. Whether you were logged in to a Google account or not, they know everything you've ever searched for, what search results you clicked on, what news you read, and every place you've ever gotten directions to. Most of the time, thanks to things like Google Analytics, they even know which websites you visited that you didn't reach through Google.

If you use Gmail, they know the content of every email you've ever sent or received, whether you've deleted it or not. They know who your friends are, where you live, where you work, and where you spend your free time. They know about your health, your love life, and your political leanings. These days they are even branching out into collecting your realtime GPS location and your DNS lookups. In short, not only do they know a lot about what you're doing, they also have significant insight into what you're thinking.

Back in April a hacker by the name of Moxie Marlinspike came out with a Firefox addon called GoogleSharing to throw a spanner in Google's works.

The addon watches for requests for Google services such as Search and transparently redirects them to a GoogleSharing proxy server. The server contains a pool of fictitious "identities" -- including cookies -- which are used in place of any personal data you might be unwittingly supplying. The altered request is forwarded to Google, and the response proxied back to you. It all happens swiftly and transparently.

There's a few other clever wrinkles. Pooling all traffic and constantly switching identities makes even the proxy server's traffic hard to analyze, and on top of that the proxy constantly injects false but plausible search requests through all the identities it uses.

The result is that you can transparently use Google search, images, maps, products, news, etc... without Google being able to track you by IP address, Cookie, or any other identifying HTTP headers. And only your Google traffic is redirected. Everything else from your browser goes directly to its destination.

In operation, it simply requires a click on the Status Bar ...

... to enable or disable it. Brilliant!

Hidden Linux : Die Flash Cookie, Die!

Tue, 10 Aug 2010 17:11:25 +1300

Flash cookies are nasty and pervasive. Most users aren't even aware they exist because they're tucked away in hidden files. (Full details here.) Browsers don't delete them because they're browser-independent, and even if you kill 'em the companies pushing them at you can respawn them. These "zombie cookies" -- so-called because they just keep coming back from the dead -- are currently the subject of a privacy lawsuit in the States.

All good horror film fans know that killing zombies isn't sufficient, you have to stop them coming back. And that's what we're about to do.

1: Find the zombies.
Open your file browser, go to the /home/your_user_name folder and switch on View Hidden Files. (In Konqueror and Dolphin you'll find this under the View menu item.) Scroll down and click on the .macromedia file. Under it you'll find a folder called Flash_Player and under that two more folders ...

If you click the expanders (those + signs) you'll find dozens of directories you didn't know you had, each containing a *.sol file. Those are the actual cookies.

2: Back 'em up
I'm always wary of just deleting stuff like this as some of it might be important. So instead of wiping it, let's just rename the folder. Right-click .macromedia and give it another name. .macromedia-ZOMBIES will do.

3: Create a link to zombie hell
Right-click in an empty area of your file browser, choose Create New and select Basic Link to File or Directory. Under File Name enter .macromedia and under File Path enter /dev/null .

/dev/null is Linux's black hole. Anything sent there is immediately discarded, but a report is sent back that the write operation was successful. That means that from now on anything writing to .macromedia gets told, "Yep, that was okay" when in fact it was nuked.

Right-clicking on the .macromedia file (it now looks like a file and not a folder) should make this clear. Choose Properties and you'll see where the file now really points. The command line makes it even clearer. Type ls -la and you'll find a line like this:

Now use Flash for a day or two. If you don't notice any effect, you can delete the .macromedia-ZOMBIES folder.

Footnote: Players of Flash games will be affected by this as most games store high scores and levels in Flash cookie files. You may prefer something more selective. Try the Better Privacy add-on for Firefox.

PenDriveLinux : Bootable Linux on a USB Stick

Wed, 04 Aug 2010 21:59:48 +1300

If you've ever been tempted to give Linux a whirl but have been put off at the thought of installing it, it's time to take a look at PenDriveLinux.

Sure you can run most Linux distributions from a live CD or DVD, but it's not quite the same. For a start CD/DVD drives are a whole lot slower than regular hard drives meaning that you get a somewhat more sluggish experience, but their main drawback is they're not writeable. Obviously putting it on a USB stick is the answer, but how do you get it on there?

PenDriveLinux have a number of solutions ranging from their Universal USB Installer to the Linux Live USB Creator (both for Windows) through to the well-known UNetbootin (available for both Windows and Linux). If you have large USB stick you can create a multiple-boot Linux stick with MultiBoot USB.

The great thing about PDL is that they're a one-stop shop for USB installations with straightforward instructions for a huge range of distributions and a comprehensive Help section with tools, compatibility tests, cheatcodes, common BIOS USB options and directions on restoring your USB stick if everything goes pear-shaped. It' well worth checking out!

Return to Propeller Head Dept.

Wed, 28 Jul 2010 21:20:54 +1300

It's been a while, but here's a fresh collection of Linux, computer and programming wit and wisdom. Who says geeks don't have a sense of humour?

General

The Internet‭? ‬Is that thing still around‭?
- ‬Homer Simpson

If the automobile had followed the same development cycle as the computer,‭ ‬a Rolls-Royce would today cost‭ ‬$100,‭ ‬get a million miles per gallon,‭ ‬and explode once a year,‭ ‬killing everyone inside.‭
- ‬Robert X.‭ ‬Cringely

Never trust a computer you can‭’‬t throw out a window.‭
- ‬Steve Wozniak

A computer lets you make more mistakes faster than any invention in human history ‭- ‬with the possible exceptions of handguns and tequila.‭
- ‬Mitch Radcliffe

Fix a computer for a friend or family member,‎ ‏and you‭’‬ll be tech support for life.‭
‎ - ‏Danny Allen

Any significant boost in technology is indistinguishable from a rigged demo.

Most computer problems occur between the keyboard and the chair.

For Linux Fans

Q:‭ ‬What's the difference between a Windows PC and a Trampoline‭ ?
‬A:‭ ‬You take your boots OFF to jump on a trampoline.

Computers are like air conditioners‭ ‬- they stop working properly if you open Windows.‭

The box said that I needed Windows‭ ‬7‭ ‬or better‭ ‬...‭ ‬so I installed Linux.

The only people who have anything to fear from free software are those whose products are worth even less.‎
- David Emery

UNIX is basically a simple operating system,‭ ‬but you have to be a genius to understand the simplicity.
‎ - ‏Dennis Ritchie‭

Q: What's the difference between Microsoft and‭ '‬Jurassic Park‭'?
A: In one,‭ ‬a mad businessman makes a lot of money with prehistoric brutes that should be extinct. The other is a film.

Spotted on IRC:
‎<‏timer‭> M‬y penis has a Linux distribution on it.‭
<‬defz‭> M‬inix‭?

Programmers' Corner

Endless Loop:‎ ‏n.,‭ ‬see Loop,‭ ‬Endless.‭
‬Loop,‭ ‬Endless:‭ ‬n.,‭ ‬see Endless Loop.

Hacking is like sex.‎ ‏You get in,‭ ‬you get out,‭ ‬and hope that you didn't leave something that can be traced back‭ ‬to you.

Programmers are tools for converting caffeine into code.

In Ruby,‭ ‬symbols are represented with‭ ‬a prepended colon,‭ ‬eg.:flag.‭ ‬So some guy turned up in a T-shirt that said‭ "‬:sex‭" ‬which everyone at Railscamp knew meant‭ "‬Sex symbol‭"‬.‭ ‬He wore it until someone pointed out that to non-Rubyists it said‭ "‬Colon sex.‭"

If Java had true garbage collection,‭ ‬most programs would delete themselves upon execution.‭
- ‬Robert Sewell

Saying that Java‭ ‬is nice because it works on all OSes is like saying that anal sex is nice because it works on all genders.‭
- ‬Alanna

The first‭ ‬90%‭ ‬of the code accounts for the first‭ ‬90%‭ ‬of the development time. The remaining‭ ‬10%‭ ‬of the code accounts for the other‭ ‬90%‭ ‬of the development time.‭
- ‬Tom Cargill

Always code as if the guy who ends up maintaining your code will be a violent psychopath who knows where you live.‭
- ‬Martin Golding‭

The three most dangerous things in the world are a programmer with a soldering iron,‭ ‬a hardware type with a program patch and a user with an idea.‭
- ‬Rick Cook‭

C makes it easy to shoot yourself in the foot.‭ ‬C++‭ ‬makes it harder,‭ ‬but when you do,‭ ‬it blows away your whole leg.‭
- ‬Bjarne Stroustrup‭

BASIC programmers never die,‎ ‏they just GOSUB and don't RETURN.‭

Real programmers are surprised when the odometers in their cars don't turn from‎ ‏99,999‎ ‏to‭ ‬99,99A.

Any sufficiently advanced bug is indistinguishable from a feature.

Science is to computer science as hydrodynamics is to plumbing.‎

If at first you don't succeed,‎ ‏you must be a programmer.‭

Real programmers don't comment their code.‭ ‬It was hard to write,‭ ‬it should be hard to understand.

The ‬3‭ ‬Biggest Software Lies:‭
‬-‭ ‬The program's fully tested and bug-free.‭
‬-‭ ‬We're working on the documentation.‭
‬-‭ ‬Of course we can modify it!

The software isn't finished until the last user's dead.

Real geeks only

There are‭ ‬10‭ ‬kinds of people in the world ...‭ ‬those that can read binary and those that can't.

To err is human ...‭ ‬to really foul up requires the root password.

A picture is worth‭ ‬128K words.

The gates in my computer are AND,‭ ‬OR and NOT‭; ‬they are not Bill.

Q:‭ ‬What's tiny and yellow and very,‭ ‬very,‭ ‬dangerous‭?
A:‭ ‬A canary with the super-user password.

Q:‭ ‬What did Linux say to the Windows partition‭?
‬A:‭ ‬Go fsck yourself‭!

Be it ever so humble, there's no place like‭ ~

Q: Why do programmers always get Christmas and Halloween mixed up‭?
A: Because DEC‭ ‬25‭ = ‬OCT‭ ‬31

This is wonderfully subtle. If you get it, you're definitely a geek!

sudo chown‭ ‬-R us‭ ‬./allyourbase

‎And where would we be with XKCD?

Hidden Linux : agt-get secrets

Thu, 22 Jul 2010 15:32:44 +1300

apt-get is the package handling utility behind Debian-based Linux systems such as Ubuntu, Mint and Mepis. You may be using it ‘by proxy’ via GUI-based package managers such as Synaptic, but hardened Linux users tend to prefer the command line - especially as the latter has a couple of neat tricks up its sleeve.

(Not that if you’re not a super-user you’ll need to prefix the following commands with sudo - well, all but the last one ...)

The basics

apt-get
update

Resynchronise installed packages with their sources. (Always do this before an upgrade.)

apt-get
upgrade

Install the newest version of all packages installed on the system.

apt-get
dist-upgrade

Upgrade to the latest version of your distribution.

apt-get
install xxx yyy zzz

Install programs xxx, yyy and zzz along with all their dependencies.

apt-get
remove xxx yyy zzz

Remove programs xxx, yyy and zzz.

apt-get
purge xxx yyy zzz

Remove programs xxx, yyy and zzz and delete any configuration files that they used.

apt-get
check

Update the package cache and check for any broken dependencies.

apt-get
clean

Clean out retrieved package files.

apt-get
autoclean

Clean out retrieved package files, but only those that are no longer needed.

apt-get
autoremove

Remove any packages that were installed to satisfy dependencies but are no longer required.

Advanced stuff
So much for the basics, what about those neat tricks I mentioned? Well, did you know you can use apt-get to get a package’s source code?

apt-get
source xxx

Retrieve source files for package xxx.

Or its build dependencies?

apt-get
build-dep xxx

Get all the dependencies needed to build package xxx.

Or that you could get it to fetch and build the package for you?

apt-get
source xxx -b

Fetch the source code then compile it. (The -b switch means ”build it„.)

The result with be a .deb package which you can install using the Debian package manager command:

dpkg -i xxx.deb

Really advanced stuff

apt-get
moo

Try it! :)

Ouch!

Sun, 18 Jul 2010 10:00:34 +1300

Just how bad is Windows' latest effort to capture the cellphone market? According to InfoWorld:

"Windows Phone 7 is a waste of time and money. It's a platform that no carrier, device maker, developer, or user should bother with. Microsoft should kill it before it ships and admit that it's out of the mobile game for good. It is supposed to ship around Christmas 2010, but anyone who gets one will prefer a lump of coal. I really mean that."

More here: Windows Phone 7: Don't bother with this disaster

Telecom pinged (yet again)

Tue, 13 Jul 2010 21:41:56 +1300

What do you think when you see a Telecom ad? Personally, I think of a certain brand of beer because -- whatever Telecom are pushing -- my reaction is an ironical, "Yeah, right!"

Look at the company's history. Since 2003 they've been they've been warned or fined eight times for breaching the Fair Trading Act. The latest FTA case, for a 2008 "Broadband at Dial-Up prices" campaign, was settled a few weeks ago with the company crediting more than 1,300 customers who'd been misled and forking out $75,000 so Consumer New Zealand could establish "a price comparison website across all providers." (Kudos to Consumer, but don't we already have one of those in the superlative New Zealand Connections site?)

To cap it all, a few days ago Telecom Wholesale was forced to compensate Vodafone and Orcon to the tune of $1.6 million for breaching its own separation undertakings "not to discriminate between or against its wholesale customers". Add to that last October's High Court ruling that between 2001 and 2004 "Telecom used and/or took advantage of its dominant position/market power ... for the purposes of deterring potential or existing competitors in the wholesale market ..." and you have a picture company that's more like a serial offender. They just can't seem to stick to the straight and narrow and stop telling porkies.

So what do you think when you see a new Telecom campaign? "Oh goody, I must get some of that" or "Oh yeah, where's the catch?"

Sloooow OOo? This could be the answer!

Tue, 29 Jun 2010 18:02:15 +1300

One of the residual issues from my troubled Kubuntu 10.4 upgrade was a puzzling OpenOffice.org problem. Last week I finally got a chance to investigate it. The solution may surprise you!

(If you can't be bothered with the dissertation and just want to try the solution, click here.)

The problem
Package developers like tinkering with other people's code. I'm not sure why, especially when suites like OpenOffice.org come tried and tested for all flavours of operating system direct from the home website. In the case of 10.4, OOo was still at version 3.1 when I'd been using 3.2 for months.

The Ubuntu version started speedily enough, but every time I clicked to open a file it would freeze for 20 seconds. Every time.

I checked running processes, I checked top, I checked memory usage -- nothing out of the ordinary. Just 20 seconds lock-up for each and every File / Open. Damned annoying!

So I ditched it, downloaded version 3.2.1 from OpenOffice.org and tried that. The file opening problem vanished, to be replaced by sluggish start up. Hit go, up pops the splash screen and -- yes, 20 seconds later -- the program opens. Once running however, everything was fine. It was just that initial startup.

I've never suffered with sluggish OOo before and, as I said, last week I finally got round to a thorough investigation.

The Clues
The first clue came from unplugging the network lead. No network = instant start. Ah-ha!

There are tons of references to networked printers causing slow OOo, and yes, I run a networked printer. But none of the suggested solutions -- such as setting the default printer to fax or PDF -- made any difference, and none explained the reason why this should affect start-up.

So I kicked off Wireshark and watched the network traffic. That was when I spotted what was happening.

My PC's name is "asok" (I'm a Dilbert fan). Every time I started OOo, a DNS request was sent seeking the IP address of "asok.(none)" -- which doesn't exist. So the request would time out, another would be sent, that too would time out ... until eventually the seeker gave up trying and the start-up continued.

Now "asok" is associated to IP address 192.168.1.100 in my /etc/hosts file...

192.168.1.100  
asok

...so adding another name resolution in the form of ...

192.168.1.100  
asok   asok.(none)

... made my problem vanish. Yay!

But why is OOo seeking "asok.(none)" in the first place?

The Reasons
Having nailed the problem -- and therefore my precise search terms -- it was easy to find and explanation. Here is it, from a 2003 forum post by Lars Oppermann, a StarOffice (OOo's predecessor) Software Engineer:


For each user, OOo keeps a set of configuration files. Those files may
only be accessed by one instance of OOo at a given time.
One user can only run one single instance of OOo on a single given host
- but in a networked environment with transparently mounted
home-directories, two sessions on different hosts could be started
accessing the same configuration (oh the horror!).




In order to prevent this kind of simultaneous access, OOo will create a
lock-file in the root of the configuration direcory (e.g.
$HOME/OpenOffice1.1/.lock) in which it saves the starting-time,
username and hostname for the instance that has locked the
configuration. Now, if another instance is started on another host, it
sees the lockfile and warns the user.




The reason why we keep the hostname, is that in case of abnormal
termination and stale lockfile we can notice that the lockfile was
created on the same host we are running on. If that is the case, we can
take over the lockfile and don't need to display a warning, since only
one instance per user/host can run; any additional instance on the same
host would connect to the socket of the first instance and just hand
over it's commandline.

In short, it's all to do with preventing simultaneous access to the same user configuration files on a network. My guess -- though I haven't confirmed this -- is that if I'd selected the "single user" option in OOo's setup, this wouldn't have happened.

The solution
Well that's investigation and the reason. How can you try a DIY fix with resorting sniffing network traffic? After all, my solution won't work for your machine -- unless you happen to have a PC called "asok" on address 192.168.1.100 -- so here's a simple way to determine exactly what should be in your /etc/hosts...

1. Start OOo.
2. When it's running, drop into a console session and type


cd ~/.openoffice.org/3

and list all the contents of this folder ls -la You'll get something like this...


total 20

drwx------  4 geoff geoff 4096 2010-06-23 17:04 .

drwxr-xr-x  3 geoff geoff 4096 2010-01-09 11:33 ..

-rw-r--r--  1 geoff geoff 132 2010-06-23 17:04 .lock

drwxr-xr-x 18 geoff geoff 4096 2010-01-10 17:25 user

drwxr-xr-x  8 geoff geoff 4096 2009-09-21 21:09 user_backup

3. The .lock file is the one we're after. Print out its contents with cat .lock Here's mine...


[Lockdata]

User=geoff

Host=asok.(none)

Stamp=4BF3169071E73BF7D70...

Time=Wed Jun 28 17:04:48 2010

IPCServer=true

4. And there you have it; the host name that OOo searches for on start-up. Tack it to the end of the appropriate line in /etc/hosts, and you're away!

192.168.1.100  
asok

Before

192.168.1.100  
asok   asok.(none)

After

So, did that work for you? Leave me a comment and let me know.

A footnote for Windows users: You'll typically find OOo's .lock file in the folder

C:\Documents and Settings\USER NAME\Application
Data\OpenOffice.org\3

Spam Warning: Canadian Health&Care Mall

Sun, 20 Jun 2010 09:21:33 +1300

Compromised Gmail accounts are being used to disseminate spam about Canadian Health&Care Mall, a bogus site offering cheap drugs online.

The email I received consisted of "Subject: sarah carter" and a single URL in the message area. Suspicious, I didn't click on the link but copied it to my browser, anonymized myself by activating Tor, and only then hit Enter. The original link -- www.mach3fr.com/default.php -- actually took me to www.pharmacymedshealthsite.net, home of a notorious spammer.

The website actually looks professional and reassuring with FAQs, contact addresses, and testimonials, but Spam Trackers, (amongst several others), have done a detailed analysis. I'll leave you to explore their findings -- including fake licenses, fake doctors, fake registrations and even fake buildings! (You gotta love Google Street View!)


Here's their "Head Office" at 186 Brock Street, Kingston, Ontario ...		... which is really the Hotel Dieu Hospital, which occupies the entire block.

Needless to say, avoid, avoid, avoid! And if you have a Gmail account, it might be time to change your password.

Anonymous Surfing

Wed, 16 Jun 2010 09:20:01 +1300

Safeguarding online privacy and security is becoming more and more important, both for individuals and organisations, and one of the best and simplest ways of doing so is to use Tor. In short, Tor allows you to use the net anonymously, whether you're browsing or publishing information, using instant messaging or Internet Relay Chat.

"Tor's hidden services let users publish web sites and other services without needing to reveal the location of the site. Individuals also use Tor for socially sensitive communication: chat rooms and web forums for rape and abuse survivors, or people with illnesses.

Journalists use Tor to communicate more safely with whistleblowers and dissidents. Non-governmental organizations (NGOs) use Tor to allow their workers to connect to their home website while they're in a foreign country, without notifying everybody nearby that they're working with that organization."

Tor is reccomended by the Electronic Frontier Foundation (EFF) and groups such as Indymedia. It's also free and open source.

Installation
A typical installation bundle consists of three packages:

Vidalia - a configuration and monitoring GUI to allow you to control Tor.
Polipo - a caching web proxy that increases the browsing performance of Tor
Torbutton - a Firefox extension that allows you to flick anonymous browsing on and off at a button click.

You find all downloads on the download page. There are versions for Linux, Mac (both OS X and PowerPC) and Windows, with the latter coming in two flavours. There's a regular Installation Bundle, an 8.5MB package containing all the necessary goodies and automatic setups, and a 15MB Browser Bundle that requires no installation, making it ideal for USB drives. It unpacks to a Desktop folder named "Tor Browser" that you can then copy anywhere or even run in situ. Just open it and click on Start Tor Browser.exe. The package contains a portable version of Firefox that won't interfere with your installed version.

(You'll find full installation details on the Documentation page.)

Windows installation adds the Vidalia control to your Taskbar...

...allowing you to control and configure Tor

Testing
To activate/deactivate, simply click the Tor control on Firefox's status bar...

... then check the changes on What Is My IP. Note that when you change from Disabled to Enabled or vice versa, Torbutton blocks the refreshing of tabs by clicking the Reload (F5). You need to click in the URL bar and hit Enter.

Important!
Tor's a great place to start, but simply installing it will not magically make you anonymous for ever more. Check out these warnings. You may need to change some of your browsing habits and/or tweak your software!

How long will your digital data last?

Thu, 10 Jun 2010 10:47:25 +1300

How long will your digital archives last? It's a question I attempted to answer back in our April print issue, and I came up with the following table, drawn from a number of sources...

Media	Usable life (years)
CD (factory pressed)	25
CD-R (cyanine and azo dyes	8-10
CD-R (phthalocyanine dye, gold metal layer)	100
CD-R (phthalocyanine dye, silver metal layer)	25
CD-RW, DVD-RW, DVD+RW	8-10
DVD (factory pressed)	25
DVD-R, DVD+R	20
Flash drive	10
Tape - Analogue	20
Tape - Digital	10-15

Estimated storage life for media stored under ideal conditions.

It seems I was a little optimistic. According to the French National Centre for Scientific Research discs "designed to last for centuries, actually rarely lasted longer than 5 to 10 years." In the most severe cases "the data on some discs lasted just one year."

It seems that buying name-brand discs is no guarantee. "Disc production varies. In the same brand we find discs produced by different manufacturers which means their quality and how long they last for is not necessarily the same."

So what are we to do? The best advice is to be vigilent:"Every two or three years ... copy your archive onto fresh discs. And after that, because these new discs will last a bit longer, you will have to re-copy them after five or six years."

And spread your archives around: "You must have your information in two places at least -- on a hard-disc, for example, and on another hard-disc or on a recordable DVD or CD."

How to: Install Linux without a CD-Rom

Fri, 04 Jun 2010 06:08:36 +1300

I recently came across a puzzling problem: how to install Ubuntu Server 10.4 on the beast you see below.

It's a Norhtec MicroClient PC, fanless, about the size of a cigarette packet, that runs from a CF card (that large slot you see on the front). The idea was to bung a USB drive in one of the other slots and use it as a simple home backup server. We're not looking at blinding performance here, just something ticking over quietly in a cupboard doing differential backups.

The problem is this: while you can begin the installation from a USB drive, part way in it demands a CD-Rom, at which point you enter a deadly bind which I'll summarise here:

Load CD-Rom drivers? None found. Fail.
Load CD-Rom drivers? Manually select them? None found. Fail.
Load CD-Rom drivers? Manually select them? Nothing in the selection list. Fail.

Every time the result was the same ...

One alternative is to mount the CF card on a CD-Rom-equipped machine and install it from there -- but that's not satisfactory because of hardware differences between the two machines. Another is to do a network installation or internet installation, both of which, frankly, involve a lot of mucking around, to say nothing of requiring a pre-exsting a network.

There must be a simple answer, I thought. And there is!

I searched high and low until I finally came across this, a brief how-to on the Acer Aspire Revo User forum. The answer, it turns out, is blindingly obvious: start with two copies of the installation image, boot with the first, then mount a second on a virtual CD-Rom and continue from there. Here's the process, step-by-step. You'll need a USB stick of at least 2GB.

1. Download Ubuntu and burn the image to the USB drive as usual. (Excellent details on how to do so at Step 2, here.)

2. Add a second copy of the .iso file. In this case I copied ubuntu-10.04-server-i386.iso to the USB.

3. Boot and install as usual in the targe machine until you reach the "Load CD-Rom drivers?" step. Choose No then, at "Manually select?" choose Yes.

4. Hit Ctrl+Del+F2 to take you into fresh virtual console and do the following ...

5. Identify your USB drive:

ls -l /dev/sd*

(Let's say we're using /dev/sdx.)

6. Create a new folder called ISO:

mkdir /iso

7. Mount the drive on it:

mount -t vfat
/dev/sdx  /iso

8. Now here's the cunning bit. Create a link from the second copy of the installation image to the target machine's CD-Rom device:

ln -sf
/iso/ubuntu-10.4-server-i386.iso  /dev/sr0

9. That's it! Hit Ctrl+Del+F1 to return to the installation screen. Where it asks you for the "Device for accessing the CD-Rom" enter:

/dev/sr0

... and you're away. Installation proceeds from what the system thinks is a CD-Rom but is actually a virtual drive linked to the USB. Oh the joys of Linux, where everything is a file!

One further point. A bit later on in the installation, at the partitioning stage, you'll be given the option of unmounting /dev/sdx. Pick No!

Hidden Linux : Example commands - dd (Part II)

Sun, 30 May 2010 21:37:07 +1300

Last time I covered the basic use of dd, Linux's "Convert and copy a file" command. Here are a few more things you can do with it, some trivial, some useful.

File Conversion
Convert a file to uppercase:

dd if=filename of=filename
conv=ucase

Convert a file to lowercase:

dd if=filename of=filename
conv=lcase

(Incidentally, if you leave out of= output gets written to "standard output" -- which defaults to the screen.)

File rescue
If a video or sound clip won't play because of bad blocks, copy it, telling dd to ignore the corrupt stuff

dd if=badfile.wav
of=fixedfile.wav conv=noerror

Wipe all the free space on a partition
(ie: Deleted files you don't want recovered)

dd if=/dev/urandom
of=~/trash.file

This will create a file called trash.file on your home partition and fill it with random characters. Eventually dd wil stop with the message No room left on device meaning all free space has been consumed. Then simply delete trash.file with:

rm trash.file

Note that dd only overwrites, it doesn't provide a cryptographic deletion. For that you're better off with srm and sfill. (See here.)

Look at your disk
If you have the program hexdump installed (it's available in most standard repositories), you can check out the contents of your hard drive.

Look at the first sector on your hard drive:

dd if=/dev/sda count=1 |
hexdump -C

dd defaults to a byte count (bs=) of 512, so this will show the first 512 bytes on your disk. (The first 446 are the MBR, the remainder are the partition table.)