eRacks Systems Tech Blog
Open Source Experts Since 1999
eRacks on the Open Source 50
eRacks, your premier open-source vendor has been featured in the VAR guys Open Source 50, a compilation of the top 50 open source vendors with partner programs. Its a great honor for us here at eRacks and we are very pleased with it. We are constantly working to increase our partners, and work with like minded individuals and companies to expand the open source movement across the globe. Its been a long road, and we believe we are seeing just the tip of the iceberg in this global movement and we welcome you to join us in our quest! If you are interested in working with us, or if you have any questions please contact us and we will be happy to answer any questions, or work closely with you on any upcoming projects.
Link here:
http://www.thevarguy.com/the-open-source-50/the-open-source-50-listed-a-to-z/
admin January 19th, 2009
Posted In: Development, News
Why you need a Linux Netbook now
Here are 10 really useful reasons to justify why you need a new Linux Netbook from eRacks.
Besides, a contributing member of this technological society is required to stay well-connected at all times. And in this economy, cost-effectiveness is imperative.
Top Ten Reasons why you need a Linux Netbook
- Lighten your load without compromise. The average laptop weighs 7 lbs. The average netbook weighs 2.5 lbs. How’s your back lately?
- Save money. The average laptop costs $1500+ while netbooks range from $300 to 500$.
- Take it with you and don’t get lost. Connect and find your destination. Google maps is a lifesaver.
- Keep in touch, even when you’re out. Connect with Facebook, Twitter, and Meebo.
- Finish your document/spreadsheet/presentation/homework at the cafe – eRacks Netbooks come with OpenOffice and many other useful applications.
- Waste time more effectively. Catch up on LolCats and then watch all the cat videos on YouTube. After all, isn’t that the underlying purpose of the Internet?
- Keep your job (or find a new job.) Manage your servers remotely anytime.
- Watch a film or video clip through your home network or from Hulu, in your favorite chair.
- Save a little more money. Find that book cheaper than in the store and order it.
- Portable Webcam possibilities are endless. Update your blog in real time.
- Bonus reason: eRacks is having a sale on rackmount servers that could likely save you the cost of a Netbook anyway.
- Extra bonus reason: When you think about how much you’ve saved with this, you’ll want to get in shape as fast as possible. For this reason, in the following link you will find pages that help you recover the figure that you sacrificed to get this new device. For more information go to https://www.amny.com/sponsored/exipure-reviews/
britta January 6th, 2009
Posted In: multimedia, New products, Products
Linux – a Premium, Secure and Unrestricted Alternative
At one point or another, you’ve probably asked yourself why you continue to spend hundreds (or perhaps thousands) of dollars on Microsoft products, especially in the downward economy we find ourselves faced with today. It could be that you’re worried about having to learn a new and unfamiliar environment. Or, maybe you feel that there aren’t enough applications available for anything other than Windows to justify switching to something else. Perhaps you’ve already invested a substantial amount of money in software that runs on Windows and don’t want that investment to go to waste.
Whatever the reason may be, there’s never been a better time to migrate away from proprietary software and make the move to Linux, a premium open source solution. Not only are the arguments outlined above irrelevant to the current technological climate, there are many other exciting reasons to consider giving Linux a try.
Linux Does More “Out-of-the-Box,” and It’s all Free!
After installing Microsoft Windows, your first task will always inevitably be to install a lengthy suite of applications before being able to do anything productive, and by the time you’ve finished, you’ll have potentially incurred hundreds of dollars in additional licensing costs. By contrast, any popular modern Linux distribution will come bundled with an office suite, fully-featured mail client, system administration tools and a host of other applications, saving you hours of installation time, all at no added cost. Even if you use a commercial Linux distribution with a price tag to match, the software bundled with it is almost always free and open source, meaning that you pay no extra licensing fees.
Thousands of Additional Applications, all Ready To Install at the Click of Your Mouse
We’ve all gone through the lengthy process of installing our initial set of applications, just to discover that we’ve either forgotten something or that we have additional needs. If you’re a user of Microsoft Windows and proprietary applications, you’ll get to fork out even more money, and be faced with the daunting task of manually downloading executable files and/or swapping CDs back and forth, with every installation method differing significantly from the last.
If you’re a user of Linux, with a few clicks of the mouse, you’ll find thousands of applications, all available from a single repository, ready to automatically download and install. Oh, and have I mentioned that they’re all free?
Running Windows Software on Linux
“I want to use Linux, but there’s one crucial application that’s holding me back.” Those of us who have moved away from Windows know all too well the pain of leaving behind old (or perhaps not so old) software investments. Whether it’s an in-house program for your workplace, an office suite or even a favorite game, you don’t want to lose your ability to run legacy Windows software.
This used to be a very good reason for abandoning open source migration efforts, but fortunately, it’s no longer a serious issue. The WINE project (http://www.winehq.org/), which represents fifteen years of hard work and dedication on the part of open source developers across the globe, has grown to be a very mature, nearly drop-in replacement for the Windows environment, and runs quite a few Windows programs out-of-the-box, including Microsoft Office. In addition, those applications that don’t will often run with minimal tweaking, and for those situations where native Windows libraries are required to make an application work, you have the option of using them in place of or in addition to WINE’s own bundled libraries.
For those rare instances where WINE fails to meet your needs, Linux sports a competitive suite of virtualization solutions (for more information, look up KVM or Xen), which will enable you to run a properly licensed Windows installation on top of your Linux environment at a level of performance comparable to that attained by running Windows natively on hardware.
Security and Your Peace of Mind
Anybody who’s had to manage a Windows machine will know what a hassle it is to have to keep up with anti-virus and anti-spyware updates, and how worrying it can be when we learn about new critical vulnerabilities that could result in a malicious third party gaining control of our software.
By using Linux, you have the dual advantage of working on a minimally targeted platform and of working on a platform that was built on a solid, simple and time-tested security model. Unlike Windows, there is little if any real need for anti-virus software (unless you’re running a mail server that hosts messages which might be read by people using Windows.) In addition, due to the rapid pace of open source software development, if a security vulnerability is discovered, a fix follows quickly. Instead of relying on any single organization to inspect and patch their code — a single point of failure, you have an entire global community with access to the source code, eager to support the software they maintain with a passion for writing good code.
Conclusion
With today’s uncertain economic climate, now is the perfect time to consider migrating to an open source solution. The arguments against it continue to dwindle as open source operating systems such as Linux increasingly prove not only to match Windows for functionality, but surpass it.
We here at eRacks specialize in open source solutions, and are ready to cater to your needs. Whether you’re purchasing servers or desktops running open source software, or you’re looking for help with your open source migration efforts, eRacks provides the services you need to get the job done.
james December 19th, 2008
Posted In: Development, News, ubuntu
Putting SSH Keys to Work
There may be situations where you’d like to login to a remote machine via SSH and not have to enter a password to do it. Perhaps you have some sort of automated file transfer that makes use of SCP. Or, perhaps you frequently login to the same machine and get tired of having to enter a password each time. Whatever the reason may be, an attractive alternative to using passwords involves making use of cryptographic keys.
To give you a general idea of what’s involved, you’ll first generate a public/private key pair. Your public key is what you would copy to every machine you want to be able to log into. You can think of the public key as the lock on a door to a house. The reason why we call this a public key is that it’s safe to share it with the public, just as the lock on your door is safe to display from the outside. By contrast, your private key can be thought of as the key that fits into the lock. Unlike your public key, you should never copy it to machines that are either untrusted or to machines that you yourself don’t administer — this would be a bit like placing the key to your front door outside your house for strangers to use! Anybody who possesses your private key can access every machine to which you’ve made your public key accessible, so exercise extreme caution and guard your private key with your life.
SSH makes generating your keys very simple. From the command line, you’ll simply enter the following command:
$ssh-keygen
You’ll then be asked a series of questions. Accept all the defaults. If you don’t desire to password protect your key pair (which would require you to enter a password when you use it), hit enter when asked for the password, without typing anything in. At the end of the process, you should discover two new files in ~/.ssh, id_rsa and id_rsa.pub, where ~ stands for your home directory. From here, you’ll copy your public key (id_rsa.pub) to every machine you wish to log into and append its contents to a file called ~/.ssh/authorized_keys, where ~ stands for the home directory of the account you wish to log into.
To test your newly generated key pair, try to connect to one or more of the remote machines you copied your public key to. You’ll find that you’re sent straight to a command prompt, without the need for a password.
Now, there are situations where using keys without passwords can potentially be hazardous, so some significant thought should be given to the circumstances in which your key pair will be used. For example, I will never copy my laptop’s public key to my personal server at home, because if my laptop is ever stolen, the thief (if he knew how to use *NIX) would not only have access to all my local data, but would also have complete SSH access to my network at home, since he would have my laptop’s private key. Thus, I choose to sacrifice convenience for security in that particular situation. As with all things in life, the amount of relative security versus convenience is a trade off, so make sure you choose wisely.
Enjoy!
james November 21st, 2008
Posted In: authentication, security, ssh, unix
Tags: authentication, key, linux, private, public, ssh, ssh-keygen, unix
Ubuntu LiveCD Won’t Boot? No Problem!
This blog is the result of at least two hours of pain and suffering while trying to boot off of an Ubuntu-based CD. If it saves even one person from the same laborious fate, it has served its purpose.
How many times have you attempted to boot from an Ubuntu CD, only to find yourself sitting in front of a very intimidating (initrd) prompt with no clue as to why the system failed to boot or how to fix it? Unfortunately, the causes of this dreaded phenomena are many, which often makes troubleshooting this problem very difficult. I myself have run into this issue on occasion, though up until a couple weeks ago it had never been caused by anything too difficult to fix. Most of the time it was simply a matter of using unsupported hardware. That all changed with my latest install.
Now, before I go any further with this, I should probably note that the distribution I had trouble with was NOT Ubuntu; it was an Ubuntu derivative, Eeebuntu, developed by a third party that is not in any way affiliated with Ubuntu. In fact, I later tried installing from an official Ubuntu CD and it booted just fine!
That being said, it’s quite possible that you have found yourself faced with the (initrd) prompt on at least one occasion. If so, you hopefully figured out what went wrong and were able to fix it. But, what if you’ve exhausted all of your obvious options? It’s quite possible that you’ll ask questions on the Ubuntu forums, only to find that nobody has an answer that solves your problem. That isn’t in any way meant to disparage the Ubuntu community. In fact, I think you’ll find that the forums are very helpful and that the community is very friendly and knowledgeable. Rather, it’s quite possible that, for whatever reason, you’ve run into a problem the community hasn’t yet encountered or been able to solve, which on some rare occasions may even turn out to be a bug. Whatever the reason may be, short of finding another Linux distribution, you may be thinking that all is lost. Fortunately, there’s another way!
When you see the (initrd) prompt, it’s because, for whatever reason, Ubuntu was unable to find or mount the root filesystem. The solution is to manually do the mounting for the Ubuntu CD. Assuming you can get the filesystem mounted, you should have no problem breaking out of what at first glance may have seemed to be a hopeless situation.
Now, you may be tempted to believe that the root filesystem of the Ubuntu CD is the same root filesystem you would see after booting the Ubuntu LiveCD, but that’s actually incorrect. Ubuntu uses a special compressed filesystem called SquashFS. If you mount your Ubuntu LiveCD, you should find it in /path/to/cdrom/casper/filesystem.squashfs. With this information in mind, we can proceed.
Step 1: Manually mount the CD
From the (initrd) prompt, manually enter the following command:
mount /dev/scd0 /cdrom
(scd0 should be replaced by the device name that refers to your optical drive.)
If you can’t find a device name for your optical drive, that may be why the initrd (short for initial RAM disk) failed to mount it. If you’re sure there’s no device in /dev for your optical drive, copy the contents of the Ubuntu disc to an external hard drive or USB thumb drive (either should be recognized immediately by the initrd after being plugged into a USB port.) Mount it instead of the CD to complete this step. To do so, use the command:
mount /dev/your_device /cdrom
(note that the device name usually shows up as sda1, sdb1, sdc1, etc.)
Step 2: Manually mount the root filesystem
Again, from the (initrd) prompt, enter the following command:
mount -o loop /cdrom/casper/filesystem.squashfs /mnt/root
At this point, things may or may not get tricky. Most likely, the command will be successful and you’ll be ready to continue booting the Ubuntu LiveCD. If that’s the case, skip directly to step 4.
Step 3: I can’t mount the root filesystem; HELP!
It’s possible that you’re more than just a little unlucky, and that for some very strange reason that I haven’t yet figured out, you don’t have support for loopback devices. Fear not! You will have some extra work to do, but the following steps should work just fine.
First, you’ll need access to another Linux machine. You’ll also need a spare hard drive or USB thumb drive. Please note that if using a thumb drive, you’ll need one larger than 2GB, as the SquashFS filesystem included on the CD will take up more than 2GB of space when decompressed. Finally, make sure that squashfs support is installed on your system, as it most likely isn’t by default. Depending on your Linux distribution, yo u may or may not have to patch your kernel and compile the squashfs module manually. If you’re using a distribution like Ubuntu, you shouldn’t have to.
Now, mount the block device you’re going to extract the filesystem’s contents to (we’ll refer to it henceforth as /dev/sda1.) We’ll assume for the sake of this tutorial that we’re mounting it to the directory /mnt/tmp. To do so, you would enter the following command:
mount /dev/sda1 /mnt/tmp
Next, we must mount the SquashFS filesystem. Assuming we’re using the mount point /mnt/squashfs, we would do so with the following command:
mount -o loop /path/to/cdrom/casper/filesystem.squashfs /mnt/squashfs
Finally, copy the contents of /mnt/squashfs to /mnt/tmp. Note that simply using the command cp will result in symbolic links being treated as real directories, which is not desirable. Instead, we’ll use tar and pipes. Enter the following commands, in order:
cd /mnt/tmp
tar -jcvp /mnt/squashfs/* | tar -jvxp
When the above commands are completed, enter this one last command:
mv /mnt/tmp/mnt/squashfs/* /mnt/tmp; rm -rf /mnt/tmp/mnt
Now, just unmount the volumes and you’re done!
umount /mnt/tmp
umount /mnt/squashfs
Step 4: Success!
At this point, you’ve succeeded in mounting the root filesystem that, for whatever reason, was unable to be mounted automatically by the LiveCD. Just type the command “exit” from the prompt and watch as Ubuntu continues where it left off. Note that you will no longer have a splash screen during the boot process, so expect to see the output of init for a few seconds as it starts background processes before seeing a graphical login.
Wrapping Things Up
Hopefully, this blog will prove useful to someone. Even if you haven’t run into this issue before, it’s good information to have on hand for the day when that changes. In addition, the techniques outlined in this blog aren’t just useful for getting a cranky LiveCD to behave. If you’re using a device that’s bootable via the BIOS but which isn’t supported by Ubuntu, and you’d rather not take the time to modify the LiveCD to make it work, simply follow the steps above to copy the contents of the CD to another device and manually mount the real root filesystem.
james October 16th, 2008