Tag Archives: Linux

A Slice Of Raspberry Pi



Image Couresty of The Raspberry Pi Foundation

The long-awaited U.S. release of Raspberry Pi hit snag this month when the folks behind the pint-sized PC (credit card-sized, actually) realized the units were manufactured with non-magnetic jacks. “No magnetics means no network connection,” a blog post stated on the Raspberry Pi site earlier this month.

Tech folks have been buzzing about this British non-profit start-up (The Raspberry Pi Foundation is a UK registered charity) since it announced it was taking pre-orders for its Raspberry Pi and demand outstripped supply within minutes. Originally designed to provide a cheap, versatile and powerful little PC for young people to learn programming with, Raspberry Pi has instead captured attention from the entire programming world – many of whom (myself included) are waitlisted for the $25 to $35 dollar machine (probably more like $50 after taxes/shipping).

The draw is threefold – it’s inexpensive, versatile and small. Essentially, it’s a little Linux machine on a RM11-based Broadbom BCM2835 200MHz ARM processor with up to 256MB of SDRAM, composite and HDMI outputs, USB and memory card slots. No case, no bells, whistles, etc. They have a pretty extensive FAQ – it will answer all of your technical inquiries and then some.

Sounds pretty cool – a neat little PC that programmers both novice and pro can push and pull in many directions. The Raspberry Pi team has already taken to testing this little wallet-sized computer to the max, like running Quake 3 on it with minimal issues.

Outside of the technical impressiveness and the attractively cheap price, it’s the goal of this project that deserves the most respect. From the Raspberry Pi team – “We want to see cheap, accessible, programmable computers everywhere; we actively encourage other companies to clone what we’re doing. We want to break the paradigm where without spending hundreds of pounds on a PC, families can’t use the internet. We want owning a truly personal computer to be normal for children. We think that 2012 is going to be a very exciting year.”

They’ve got the buzz. They’ve got the mission. Now, all they need is magnetic jacks. Stay tuned.


Ubuntu Linux Heads for Smartphones and Tablets



ZDNet is reporting that Canonical is intending to make the next release of Ubuntu, 12.04, a LTS (Long Term Support) release with intention of then expanding Ubuntu beyond desktops and laptops into smartphones, tablets and smart TVs, with a target of 2014 for an all-platform release.

Mark Shuttleworth, founder of Canonical, in an interview said, “This is a natural expansion of our idea as Ubuntu as Linux for human beings. As people have moved from desktop to new form factors for computing, it’s important for us to reach out to out community on these platforms. So, we’ll embrace the challenge of how to use Ubuntu on smartphones, tablets and smart-screens.” The full announcement is expected at the Ubuntu Developer Summit, which starts tomorrow and runs for a week in Orlando, Florida.

Having already been in discussions with partners for around 18 months, it seems that this is more than wishful thinking, but one can’t help feel that the whole Palm-HPWebOS debacle bodes badly for any company wanting to get in on the smartphone and tablet space. If HP can’t make it happen with a solid OS and Zen of Palm, what hope has Canonical? When quizzed about this, Shuttleworth said that he saw “Android as its primary competitor…..We’ve also already heard from people who are already shipping tablets that they want Ubuntu on the tablet.” And of course, “Ubuntu already has a developer and customer base.”

While there’s no doubt that the mobile space is still maturing and there’s plenty of change still to come,  I have a hard time seeing Ubuntu on anything but a small niche of tablets and an even smaller niche of smartphones. iOS and Android have their foothold and Microsoft will be a solid third if Windows Phone 7 continues to deliver and Windows 8 delivers as expected. A fourth player is going to have difficulty making inroads, especially one as relatively unknown as Canonical and Ubuntu.

Smart TVs are a more plausible destination as the internal software is of less concern to the consumer. Most people buying a TV are looking at the exterior brand such as Sony, Samsung or LG, and not what’s inside, although this may change if a “Powered by Roku” or “Google TV inside” campaign runs. Plenty of change to come in this space too.

I wish Ubuntu every success.


Check File Copies with Linux Scripts



OpenSuSE logoFor several years, I’ve had an original Buffalo LinkStation NAS as my main fileserver. Being on 24×7, it’s gone through several fans and at least one hard disk, but it’s now time to retire it in favour of a LinkStation Duo which will give me more space, RAID capabilities and faster transfer speeds.

Naturally, as my main fileserver, it’s backed up. However when I copy the files to the new Duo, how do I know that they’ve all copied correctly and none have been missed? There are hundreds of thousands of files and checking each one by hand would be pointless.

Linux has lots of tools that tell me how much disk space is used, such as du, df and filelight, but they don’t always report back consistently between filesystems. Mostly for reasons of speed, they report the total size of the file blocks used to store a file and as block sizes can vary between filesystems, the total number of blocks used for a set of files will be different. For example, I have two folder sets that I know are identical and du -s on one reports 210245632 and on the other 209778684.

Fortunately, there’s an extra command line flag that will change the behaviour to take longer and sum the actual bytes. In this case, du -sb will return 214813009920 bytes on both filesystems. On the whole, I can be reasonably confident that if the total number of bytes used is the same between two filesystems, then all the files have copied correctly.

But what if the total number of bytes don’t match? How can I find the missing or truncated file? After thinking and tinkering, what I want is to get a list of files with each filesize from the old and new filesystems and then compare the two. And here’s how you do it (each section here goes on one line).

find /home/old_folder -type f -printf '%s %p\n' |
sed 's/\/home\/old_folder\///' | sort > old.txt
find /home/new_folder -type f -printf '%s %p\n' |
sed 's/\/home\/new_folder\///' | sort > new.txt
diff -wy --suppress-common-lines old.txt new.txt

If you aren’t used to Linux, this can look a bit scary, but it’s not really. The first two lines create the text files with all the files and the third line compares the two. The the first two lines are much the same in that they do the same commands but on different filesystems. There are three sections, find to list all the files, sed to chop the directory path off, and sort to get all the files in some sort of order. Here are some explanations.

find – finds files
/some/folder – where to start finding files
-type f – only interested in files (not directories or links)
-printf ‘%s %p\n’ – only print the filesize (%s) and the full pathname (%p) on each line (\n)

sed – processes text
‘s/x/y/’ – means replace x with y. In our instance, it’s replacing the leading folder path with nothing. It looks worse than it is because the slashes in the path need to be escaped by a preceeding backslash, so you get these \/s everywhere.

sort – sorts text
> file.txt – copy everything into a text file.

One of the clever things about Unix-like operating systems is that you can pass information from one command to another using a pipe. That’s represented by the | symbol, so the find command gets the information on files and files sizes, passes it to sed to tidy up which then in turn passes it on to sort before sending it to a file.

After running this set of commands on the old and new filesystems, all that needs done is to compare the files. Let’s look at the third and final command.

diff – compares files line-by-line
-w – ignore whitespace (spaces and tabs)
-y – compare files side-by-side
–suppress-common-lines – ignore lines that are the same
old.txt new.txt – the two files to compare

So what might the output of the diff be? If all the files copied correctly, you’d get absolutely nothing. Other possibilities are that the file partially copied or didn’t copy at all. Here’s what the output might be like.

598 i386/compdata/epson3.txt | 500 i386/compdata/epson3.txt
598 i386/compdata/onstream.txt <

The numbers at the beginning of the entry are the number of bytes, so the first line shows that the epson3.txt is only 500 bytes long in the new file but 598 in the old. The second line shows that onstream.txt is present in the old file but not in the new, as the arrow points to the old file.

To close the story, did I find that I had lost any files? Yes, I did. I discovered a couple of small files that hadn’t copied at all because of non-standard characters in their filenames. The filenames were acceptable to Windows but not Linux and I’d used my Linux PC to do the copying. Fortunately, the files were saved and all the scripting was worth it.

Read more on Linux at Geek News Central.


Five Backup Solutions to the Cloud for Your Computer



In this computer day and age, you want to make sure pictures, documents and more are backed up on a daily basis. Especially with hard drives that fail every day and notebooks that get stolen every day. Even if you get your stolen computer back, the thieves might have done damage like wiping the hard drive or dropping the machine altogether.

I back up my machines to different sources. I have 2 home backups and one cloud backup. The cloud backup can also be a great way to share pictures through an iPhone, Android or iPad application. Nonetheless, if my computer drive dies, if there is fire or water damage, if someone steals my computer, I don’t lose the data.

Advantages to Cloud Based Backup

  • Off-site data retention
  • access to data from multiple computers or mobile devices
  • software that will start backing up files when computer is idle
  • High encryption on backup
  • Cloud based service runs their own backups – Your data gets backed up by them, too!
  • Prices are low – There are some services that are free to a certain level.
So here are Five cloud backup solutions you can employ now:

MyPCBackup

My PC Backup
My PC Backup

MyPCBackup was ranked #1 by Top 10 Online Backups. With unlimited backup, you can make sure all your pictures, documents and more are safe. They have an option to sync multiple computers through a folder on the machine.  They also offer a money back option and full customer support.

Mac users won’t be able to use this program, which is a major downfall to this program. The “1 PC, 1 Mac” per household ratio is growing. There is also no mobile application so you can view your backup files.

Carbonite Online Backup

Carbonite Online Backup
Carbonite Online Backup

One of the more popular online backup systems is Carbonite, this unlimited backup lets you view your files from any computer, or through an iPhone, Blackberry or Android application.  Carbonite also has accidental deletion option, which means if you delete a file that was backed up, you have 30 days to restore it.

Carbonite also works on PC and Mac systems. Therefore, you could backup all your items from the old computer, switch the program to Mac and download the files. There is full customer support if needed.

Mozy Online Backup

Mozy Online Backup
Mozy Online Backup

Mozy online backup is also a PC or Mac backup. You can access your data from an iPhone and Android (no Blackberry) application. They also offer on-site backup, which means you can set up a USB hard drive and Mozy will backup to that as well. Full support and they also offer the ability to restore a file up to 30 days after deleted.

Mozy does not offer unlimited backup, though. $5.99 /month  for 50 GB and $9.99 for 125 GB. For a standard computer, you might not fill that spot – unless you take tons of pictures or create video like myself.

DropBox

Dropbox
Dropbox

You might not think of Dropbox as a online backup. However, with their open API, there are a lot of things that Dropbox can become. You can use it to sync with other computers, so it’s a great collaborative tool.

Keep in mind, it doesn’t tout itself as an online backup. You do get some great options, like short-term backup recovery.

They do have a free service for the first 2 GB, then pricing options after.

iBackup

iBackup
iBackup

iBackup is a backup for not only PCs and Macs, but also Servers. You can also back up your MySQL, Linux box Exchange, Oracle and iPhone. Therefore, it’s a full corporate backup solution. It gets pricey fast, but if you need 1.5 Terabytes of data that has to be backed up, this is a great solution.

They also have a “30 version” backup – If you change a document 29 times, then realize you need to start from the beginning, you can go into your account and pull up the first version. That can help if someone messes up a document and you don’t realize it right away.

There are  other online backup options, too. This includes items like PogoPlug or Drobo, where the files are stored at your home site. Elephantdrive, Livedrive, KeepIT are some other online backup tools.

Since it’s your data, you should research each program and see if it’s right for you. But if you have important data and need to back it up, then these options might help you with that solution.

There are also some great software solutions if you want to backup your computer to another computer. If you are on a Mac, then Time Machine is a feature you can set. Everything from backing up folders to making a full image of your computer to restore at a moments notice.

Most important – Back it up now, because you never know if you’ll get a chance to back it up later.


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Show Notes:
Firefox Release Schedule!
AT&T and Verizon told to Share!
iPad O’Scope.
BitTorrent grows up.
Microsoft and Toyota.
Robot gets Shot?
F35 Ejection Seat Test.
Computer Screen Chapstick.
UK Seizing Domains!
China says no more Time Travel?
Tethering stealing?
Fed Gov’t Shutdown?
Want Bonus get Social.
Chrome to add Malware detection.
Google Travel only if Feds can Monitor?
Samsung 1 Million to Schools.
64 Bug Fixes on Patch Tuesday!
Signal Phone Boosters to get Regulated.
Hacker says he was working with Feds.
Windows Phone 7 Update Cautions.
81 Billion Light Year Explosion.
Space Shuttle Images.
ISS Gateway to Mars.
Jailbreak it?
Vulkano TV Streamer.
Websites for iPad.
MPAA loves to Sue and little else.
Seizing Domains to Continue.
Verizon keeping iPhone users connected.
2 Million iPad 2’s.
Facebook Open Source Servers.
Sushi Blocks.
Topener!
Mini Coffee Machine.
New Fire Extinguisher.
Dish + Blockbuster = Store Fronts.
March Madness digital results!
YouTube Organizing!
ESPN Goes Live!
Vortexbox!
Vending Box
HitPad customized news.
Gmail Updates.
GoFlex Sim Review.
100 Atari Games for Ios
Homeland Security Updated via Facebook?
Time Warner off to Court.
WHS 2011 Available.
Pandora spying on you?
LinkedIn and Android.
Skype Linux Update.
Bing iPad App.
Nook Apps?
Verizon 2yr contracts only!


Network Switches and Data Transfer Speeds



I recently upgraded my home network from 100 Mb/s to 1 Gb/s by replacing the switches. The main house switch is an unmanaged 1U rack-mounted switch, with a second desktop switch. Out of pure interest, I took the opportunity to do a little bit of speed testing to see how much of a difference upgrading the switches made in terms of actual data transfer speeds.

A few basics to avoid confusion  – b/s is bits per second and B/s is bytes per second. All of the reported figures will be in MB, so converting b/s to B/s:
Fast Ethernet = 100 Mb/s = 12.5 MB/s
Gigabit Ethernet = 1 Gb/s = 125 MB/s

100 Mb/s and 1 Gb/s refer to the speed of the underlying technology but data transfers at these rates are never achieved because of protocol overheads and such. As a baseline, if I write a large file (8 GB) to my PC’s local disk, I get a data transfer of between 50-55 MB/s.

On my network, I have two Buffalo Linkstation NAS devices, one with a Fast Ethernet interface and one with a Gigabit Ethernet interface. 2 GB’s worth of data would be written to each of these devices with different Ethernet switches in place to see what actual data transfer speeds would be achieved. The following Linux command was used five times in each situation and the result averaged.

time dd if=/dev/zero of=testfile bs=16k count=16384
Switch Model Data Rate to Fast NAS Data Rate to Gigabit NAS
1U Rack
Dynamode SW240010-R(Fast) 6.2 MB/s 8.6 MB/s
TP-Link TL-SG1016 (Gigabit) 6.4 Mb/s 21.4 MB/s
Desktop
D-Link DES-1008D (Fast) 6.2 MB/s 8.6 MB/s
Netgear GS605 (Gigabit) 6.5 MB/s 21.1 MB/s

I also carried out two further tests:

  1. With Gigabit Ethernet only, I wrote to both NAS devices at the same time. The data transfer speeds were unaffected.
  2. I connected the two Gigabit Ethernet switches in series and wrote to the NAS. Transfer speeds were reduced by 1 MB/s on the Gigabit NAS to 20 MB/s. The change on the Fast Ethernet NAS was minimal.

There are several things that can be deduced from the information shown in the table above and the other tests.

  1. Actual data transfer rates are considerably less than the theoretical maximums.
  2. There’s no performance difference between rack-mounted and desktop switches.
  3. The write speed of the NAS can be a limiting factor.
  4. Gigabit Ethernet switches give large improvements with Gigabit Ethernet devices.
  5. Gigabit Ethernet switches give small improvements even with Fast Ethernet devices.
  6. Keep the number of switches in the network path to a minimum.

 


The Best Ever SuSE Linux – v11.4



OpenSuSE 11.4 was released back on 11 March so this weekend I took the plunge and upgraded my main PC from 11.3 to 11.4. And less than two hours later, I had the best ever SuSE running on my PC.  Here’s how I got on…

SuSE offer two methods of upgrading, the first being an on-line update and the second being the more traditional iso image download, burn and boot. I chose the latter as the guidance on SuSE’s website suggested that this would be more reliable. It also means that if the upgrade does fail and I needed to carry out a complete install from scratch, I already had the media to hand. Before booting from the DVD to upgrade, I backed up all the user files from the home partition and made copies of the important files – fstab, hosts, passwd, groups, auto.nas and so on.

Booting from the DVD, the installer goes through the usual licensing screen before analysing the existing system. As I had 11.3 previously installed, the installer gave me the option to upgrade, which I choose. After more analysis, it gives a summary of the changes required before asking permission to proceed – which I gave.

About 35 minutes and 250-odd packages later, the PC rebooted, loaded Linux and displayed the login screen. I entered my username and password, and the screen faded to the X desktop, with all my icons and widgets still there. Sweet!

Even more surprisingly, all the 3D window effects worked out of the box. That’s never happened before – normally you have to download drivers from nVidia or ATi before all the graphic goodness works smoothly. To be fair 11.3 was a “nearly” release. While the applications and tools worked, the 3D effects were a bit hit or miss. Sometimes they worked, sometimes they didn’t. But 11.4 hits it on the head.

The 3D eye candy is very slick. I run a 3 x 2 virtual desktop and the scrolling between the desktops is super-smooth, making it feel like one giant desktop. Windows glide in and out as they open and close. But by far my favourite effect is when you have overlapping windows and you want to bring one to the foreground. The upper window slides down the screen and then slips behind the lower window, bringing it to the front. Think of taking off the top sheet from a pile of paper and putting it to the back. So cool.

I’ve taken a couple of screenshots but (a) it’s really hard to catch the window closing when pressing the PrtScn button and (b) there’s no sense of the animation.

To finish off the installation, I added the ubiquitous Packman repository to load up all the unofficial multimedia goodies, such as DVD playing and video encoders.

Although it’s only been a few days, I’ve not encountered any problems at all with 11.4 and I’ve discovered that several of 11.3’s bugs have been fixed. Most of the major packages have been updated and OpenOffice.org has been replaced by LibreOffice (which is a whole sorry story in itself). Everything seems to be working fine.

If you want to try SuSE without messing with your current setup, there are live DVDs available for download. I run the KDE desktop rather than Gnome.

While it may be a little premature, I think this is the best SuSE ever.


OpenSuSE Linux 11.4 Released



The latest version of OpenSuSE Linux, 11.4, has just been released and it’s chock full of new features. The replacement for OpenOffice.org, LibreOffice, gets its first major outing, KDE gets bumped to 4.6 and Gnome comes in at 2.32.

There’s a also a pile of updates to applications, including Empathy, RhythmBox, Amarok, Totem, Evince and Shotwell. For developers, GTK 3 is included so Gnome applications can be upgraded to the new framework.

I’m running 11.3 so I’ll be downloading from the mirrors tonight and upgrading over the weekend. I’m looking forward to the new eye candy provided by the KDE Plasma Desktop Workspaces. Ok, so I’m shallow.

If you want to try OpenSuSE, there’s a live version as well, in both KDE and Gnome flavours. Give it a whirl.


Goodbye Ubuntu, Welcome Back SuSE



Some of you may recall that early last summer, I left my long-term Linux partner OpenSuSE for Canonical’s Ubuntu – the post is here. I thought it was going to be forever but I’m afraid it hasn’t worked out and SuSE has taken me back.

The original problem was that I couldn’t get SuSE 11.2 to install on new hardware and while Ubuntu 10.04 happily installed onto the new motherboard and harddrives, it’s been the legacy hardware that has been the root of the problem. Specifically, applications that wanted to access my SCSI scanner had to run as root, I completely failed to pull DV video from a video camera over Firewire and I couldn’t configure, never mind watch, my TV card. Scouring the newsgroups, I wasn’t alone. Perhaps naively, I thought that these problems would be fixed with Ubuntu 10.10 but alas, they persisted.

During the Christmas holidays I’d finally had enough – I can’t remember what finally caused me to snap but I downloaded OpenSuSE 11.3, burnt the DVD and rebooted. This time I didn’t encounter any of the previous problems from 11.2 and the installation went smoothly. It was like coming home – everything worked. Scanner – check, DV – check, TV – check.  And although returning to KDE desktop from Gnome, I have decided to keep some of the Gnome-based apps in preference to the KDE equivalents. gPodder is now my default podcatcher and Amarok has been replaced by RhythmBox.

It’s interesting times for OpenSuSE. In November, parent company Novell was sold to Attachmate but allegedly it’s business as usual. Version 11.4 will be out in a few weeks too.

There’s no doubt that some parts of Ubuntu were very seductive, such as package management, but I’m sorry Ubuntu…you’ve been dumped.


Amarok & KDE Crash Reporting – FAIL



Sigh. I love Linux but there are times when you realise it’s never going to take over the world…

I was working with Amarok, but the program crashed completely every time it hit a certain file in my audio library. This wasn’t a big deal but being a helpful soul, when I was presented with the option to send crash information back to the coders, I clicked on “Ok.”  And this is where it all went wrong.

First of all, after showing the stack trace (whatever that is), the crash handling dialog tells me that it’s not much use without the debug symbols, but the package to do that isn’t installed.  Did I want to install the necessary package?  So I said, “Yes,” still being a helpful soul.

Next, an error pops up saying that it can’t find the package and could I add a repository via the package manager?  Of course, the error message doesn’t tell me either the package that’s needed or the name of the repository needed. Being an ever-helpful soul, I figured out by myself that I need to enable the debug repository in the package manager, after which the crash handler was able to load the package and add the debug symbols. Hurrah!

So I hit  “Next” and I get presented with a username and password dialog for the KDE bug database. Apparently I can only log crashes if I’ve registered with the bug database. At this point I gave up being a helpful soul and closed the dialog.

So, for Amarok and KDE developers, here’s a clue. If you want feedback from your users on what’s going wrong with your applications, don’t make it so hard to give the information. Having agreed to give the feedback, that should be it, job done. I should not have to install a package, configure a repository and get a username for some website I’m never going to visit.

Even Dr Watson wasn’t this stupid.