Certifying Linux technicians is a developing trend. The Linux OS is growing up. This is pushing many computer engineers and IT professionals to prove their skills as programmers and systems administrators.
While not quite a common job requirement yet, some employers and high-level software developers are looking for Linux-certified employees. This is similar to the existing standard of expecting Microsoft (Nasdaq: MSFT) Webroot AntiSpyware 30-Day Free Trial. Click here. Latest News about Microsoft certified computer technicians and IT professionals.
"Originally, certification didn't have a strong base in Linux. Now that Linux has moved into business Over 800,000 High Quality Domains Available For Your Business. Click Here. mainstream, people are making that leap to prove themselves," Jim Lacy, president and CEO of the Linux Professional Institute, told LinuxInsider.
The trend today is for computer professionals to move away from proprietary software products in favor of developing their industry-wide skills, Lacy added.
Not a License
Linux certification programs do not qualify those who pass the rigorous examinations to meet any licensing standards. No license exists for an IT professional to practice computer engineering. The computer industry has not developed a licensing requirement like other skilled trades such as electricians, plumbers and communications professions.
In part, professional licensing does not fit the unusual workplace practices of the computing industry. Those who develop Linux products are in an especially unusual situation. Linux professionals were born from a distributed workforce tied to an online community.
"The IT industry needs certified technicians. Originally Linux training was a measure of suitability to work in the IT field to reduce help desk Latest News about help desk costs. It became a mindshare about how to advance skills in the industry," Eric Wenck, vice president of Prometric's IT testing segment, told LinuxInsider.
Dual Options
IT professionals looking to be Linux certified have two types of programs to consider. One certification track is vendor neutral, concentrating on core Linux programs and command line skills that apply to all Linux distributions. The other certification track is aimed at computer engineers specializing in a major Linux enterprise distribution such as Novell's (Nasdaq: NOVL) Latest News about Novell Suse Linux or Red Hat (NYSE: RHT) Latest News about Red Hat Linux.
Fuzzy Career Path
Linux certification is not at this time a hard and fast requirement for most IT professionals and others who work as Linux software developers. In fact, many Linux experts are not certified by any program but are still are well qualified based on their programming skills, explained Wenck.
"It is not a career prerequisite. It is not a de facto standard. Should it be? I don't know yet. Some elements within the IT industry are working towards that end," Wenck said.
Not having set standards for its professionals may be sending mixed signals about the computer field. The IT industry is not focused on licensing, and Linux certification -- or even Microsoft certified training -- is not yet a rite of passage.
"Barbers need licenses to cut hair. Programmers of hospital networks don't need any certification to maintain computers that have life-and-death implications on patients," Wenck quipped.
Established Programs
The Linux professional work force generally has four major programs for those engineers looking to prove or improve their skills. Sources familiar with the standards involved said there is considerable overlap in testing and content.
"There is a handful of certification programs out there for different aspects of Linux. There is the overall knowledge of using Linux -- and thereby an extension to Unix in general -- and then there is the certification for knowing about a certain brand of Linux," Sameer Verma, a professor of information systems at San Francisco State University, told LinuxInsider.
Certification programs generally test one of three skill levels, said Lacy. Entry-level measures knowledge based on one year to 18 months of experience. The second level measures two to three years of experience, and the enterprise professional level measures the most experienced skills.
Linux professionals should not confuse Linux training with Linux certification, according to Wenck. Training focuses on product knowledge, job skills, IT operations and project management. Certification measures different areas of actual Linux knowledge with tests, he said.
Program Highlights
CompTIA offers a vendor-neutral certification in Linux+ as one of several computer-related programs. Its tests measure a developer's knowledge of six to 12 months of practical Linux experience. Some major computer companies, such as Fujitsu Latest News about Fujitsu and Avaya (NYSE: AV) Latest News about Avaya, now require CompTIA Linux+ certification for their support staff.
Linux Professional Institute offers a three-tiered rating program. The Institute is a non-profit organization that fosters standards in the professional use of Linux, open source and free software. LPI requires each certification candidate to pass two exams per level. Junior level administrators comprise Level 1 (LPIC1) is a prerequisite for taking the Level 2 (LPIC2) exams for the intermediate level rating. The top level is Level 3 (LPIC3).
Novell offers two Linux certification levels. One is Certified Linux Professional (CLP); the other is Certified Linux Engineer (CLE). This second certification level covers more advanced administrative skills.
A relatively new arrival to the certification scene is Canonical. Distro newcomer Ubuntu/Kubuntu has started dabbling in certification exams. That company has both professional and user level exams. Canonical uses LPI exams as a base and adds Ubuntu-specific questions of its own, said Lacy.
Extensive Red Hat Grades
Red Hat Linux Training offers certification in five categories. Red Hat Certified Technician (RHCT) is for technicians who set up new Red Hat Linux systems and configure them to networks. They must must pass a half-day lab exam.
Red Hat Certified Engineer (RHCE) is for advanced system See the HP Proliant DL380 G5 Server with Systems Insight Manager - Click here. administrators. This certification requires passing a day-long lab exam consisting of three elements. There is a written test, a server install and network services configuration lab and a diagnostics and troubleshooting lab.
Red Hat Certified Architect (RHCA) requires certification candidates to plan, design and manage an open source infrastructure in large, complex environments. Red Hat Certified Security Specialist (RHCSS) candidates must pass three examinations showing advanced skills in using Red Hat Enterprise Linux, SELinux and Red Hat Directory Server.
Certifying Costs
LPI exams cost about US$150 an exam. Red Hat exams cost a lot more -- $750 or so, according to Verma.
"Red Hat packages are a lot like MCSE (Microsoft Certified System Engineer) type exams. Five-day training and exam at a bundled cost of $2,500 to $3,000 or so," he said.
In general, Linux+ certification exams from CompTIA cost $232 for non-members and $186 for CompTIA members.
Get Training
Some computer engineers take the certification test based on their accumulated knowledge from years of experience in the field, noted Verma. Others prepare through a five-day crash course. Either way, their goal is to add legitimate credentials to their resumes or meet a job requirement.
Those looking to go through intense training in preparation for tests should brace themselves when it comes to costs. Training courses and self-study materials are not cheap. You can expect to pay up to $14,000 for many of the proven methods and materials.
"The crash course is not going to be helpful if you start from zero. In my experience, if you have been working as an admin for at least a year or two, your certification process will be relatively easy," said Verma. "Often, admins fall in the trap where they know of a small subset of commands for their work and tend to disregard other aspects of certification. So you may know a lot about cron jobs but very little about iptables for network security. A certification will aim to test on all aspects of a system."
Finding Resources
Linux training centers operate around the country. For a detailed list of training facilities, check out this Web site.
Another source for training options is to purchase self-study books. This Web site is a good starting point for sources of instructional DVDs.
One must-have method for preparing for Linux certification is practice tests. A good source of practice tests is available here.
Testing Sites
To find out more about specific testing programs, try visit these Web sites. Both organizations offer international testing facilities at 3,400 locations in 120 countries.
Prometric is an international technology firm that provides testing and certification programs. It offers several types of Linux certifications directly through its own test centers and through various partners worldwide.
Pearson VUE provides testing services for licensure, certification, academic admissions, regulatory and government testing service markets. It has offices and affiliated test centers in 162 countries.
Monday, January 7, 2008
Tuesday, July 31, 2007
linux supercomputer by NASA
NASA has selected an SGI Altix supercomputer to help it meet future high-performance computing requirements. The new system will be the first supercomputer to operate 2,048 processor cores and 4TB of memory under control of one Linux kernel, creating the world's largest single-kernel Linux system, NASA and SGI announced this week.
Driven by 1,024 Dual-Core Intel Itanium 2 processors, the new system will generate 13.1 TFLOPs (Teraflops, or trillions of calculations per second) of compute power. Based hundreds of computer "blades" that each sport a pair of dual-core processors, the system provides an extremely high density of compute power per square foot, enabling NASA to pack more computing power into its supercomputing center. NASA also acquired an ultra-dense 240TB SGI InfiniteStorage 10000 system to efficiently handle the massive data storage requirements.
At 13.1 TFLOPS, the new Ames supercomputer would rank 64th on the latest list of the world's Top 500 supercomputers. The vast majority of high-performance supercomputers now run Linux, but most of them do this by running multiple instances of Linux over a cluster of computers.
NASA's new SGI Altix system is expected to be installed in August at the the NASA Advanced Supercomputing facility at the Ames Research Center at Moffett Field, Calif. The 2,048 processor-powered supercomputer operating under Linux can accelerate scientific research by making all of the system's processors and memory available to solve a single problem or several problems at once.
The Altix system uses a single instance of Linux, which runs in SMP (symmetric multiprocessing) mode up to 2,048 processors as though they were multiple cores on a single PC motherboard, according to Jill Matzke, Product Manager for SGI's Altix line. However, the latest production Linux kernel, version 2.6.22.1, supports a maximum of 1,024 simultaneous processors in SMP mode, she said.
Each blade computer contains two dual-core processors
Based on NASA's 2,048 processor requirement, SGI therefore is developing necessary modifications to support the 2,048 processors. The company has submitted these to the development community for inclusion in future kernel releases, Matzke said.
SGI's "NUMAlink interconnect" lets a single Linux kernel share up to 2,048 processors
"Supercomputers play a critical role in many NASA missions, including new space vehicle design, global climate studies and astrophysics research," said Piyush Mehrotra, who leads the NASA applications group that is steering the technology upgrade effort. "We look forward to evaluating SGI's latest HPC offerings as part of our long-term technology refresh effort."
The SGI Altix architecture accommodates the broad range of projects being pursued by NASA scientists, whose work demands both cluster and shared-memory computing architectures. NASA supports scientists and engineers throughout the U.S. who work on projects such as designing spacecraft, improving weather and hurricane models, and understanding the behavior of the sun. Many NASA projects require large, complex calculations and sophisticated mathematical models that can be efficiently handled only by a supercomputer, NASA said.
"NASA scientists already rely on SGI Altix systems for a range of research, from designing safer, more advanced spacecraft to understanding the long-term effects of climate change," said Robert "Bo" Ewald, SGI's CEO, in a statement. "These researchers pursue work that is essential not only to the United States, but to the world at large. SGI looks forward to continuing to work with NASA as it seeks leading-edge HPC compute and data management solutions to meet its evolving needs."
Driven by 1,024 Dual-Core Intel Itanium 2 processors, the new system will generate 13.1 TFLOPs (Teraflops, or trillions of calculations per second) of compute power. Based hundreds of computer "blades" that each sport a pair of dual-core processors, the system provides an extremely high density of compute power per square foot, enabling NASA to pack more computing power into its supercomputing center. NASA also acquired an ultra-dense 240TB SGI InfiniteStorage 10000 system to efficiently handle the massive data storage requirements.
At 13.1 TFLOPS, the new Ames supercomputer would rank 64th on the latest list of the world's Top 500 supercomputers. The vast majority of high-performance supercomputers now run Linux, but most of them do this by running multiple instances of Linux over a cluster of computers.
NASA's new SGI Altix system is expected to be installed in August at the the NASA Advanced Supercomputing facility at the Ames Research Center at Moffett Field, Calif. The 2,048 processor-powered supercomputer operating under Linux can accelerate scientific research by making all of the system's processors and memory available to solve a single problem or several problems at once.
The Altix system uses a single instance of Linux, which runs in SMP (symmetric multiprocessing) mode up to 2,048 processors as though they were multiple cores on a single PC motherboard, according to Jill Matzke, Product Manager for SGI's Altix line. However, the latest production Linux kernel, version 2.6.22.1, supports a maximum of 1,024 simultaneous processors in SMP mode, she said.
Each blade computer contains two dual-core processors
Based on NASA's 2,048 processor requirement, SGI therefore is developing necessary modifications to support the 2,048 processors. The company has submitted these to the development community for inclusion in future kernel releases, Matzke said.
SGI's "NUMAlink interconnect" lets a single Linux kernel share up to 2,048 processors
"Supercomputers play a critical role in many NASA missions, including new space vehicle design, global climate studies and astrophysics research," said Piyush Mehrotra, who leads the NASA applications group that is steering the technology upgrade effort. "We look forward to evaluating SGI's latest HPC offerings as part of our long-term technology refresh effort."
The SGI Altix architecture accommodates the broad range of projects being pursued by NASA scientists, whose work demands both cluster and shared-memory computing architectures. NASA supports scientists and engineers throughout the U.S. who work on projects such as designing spacecraft, improving weather and hurricane models, and understanding the behavior of the sun. Many NASA projects require large, complex calculations and sophisticated mathematical models that can be efficiently handled only by a supercomputer, NASA said.
"NASA scientists already rely on SGI Altix systems for a range of research, from designing safer, more advanced spacecraft to understanding the long-term effects of climate change," said Robert "Bo" Ewald, SGI's CEO, in a statement. "These researchers pursue work that is essential not only to the United States, but to the world at large. SGI looks forward to continuing to work with NASA as it seeks leading-edge HPC compute and data management solutions to meet its evolving needs."
Friday, July 20, 2007
How to Reset forgotten Root passwords in Linux
1.0 Introduction
Suppose you have just taken over as a new system administrator from another person just before they left and they forgot to give you the root password. Now, let's say you have to install the latest version of PHP on the system so that the sales department's website works the way its supposed to. You have to get the website up yesterday, since you are losing money every minute it doesn't work. Or maybe you simply need to add another user to the system.
The above scenarios are just two possible cases when you might need to reset the root password on a system; there are hundreds of other possible cases when you might need to do this, but I am not going to list all of them. Most of us know what to do when something like this happens on a Windows machine, but not a lot of us know how to recover lost passwords from Linux machines. This document attempts to rectify this situation by telling you about the different options available to recover passwords from YOUR machines. (Don't use this to break into other people's systems as that would be stupid and will get you into big trouble if you are caught.)
1.1 Disclaimer
Use the information in this document at your own risk. I disavow any potential liability for the contents of this document. Use of the concepts, examples, and/or other content of this document is entirely at your own risk.
The information in this document should only be used to recover passwords from machines to which you have legal access. If you use this information to break into other people's systems, then I am not responsible for it and you deserve your fate when you are caught. So don't blame me.
You are strongly advised to make a backup of your system before performing any of the actions listed in this document.
1.2 Credits
In this version, I have the pleasure of acknowledging the following people without whose input this would have never seen the light of the day:
* The community at http://www.justlinux.com, for the really helpful debate about this topic in one of their threads.
* The creators and maintainers of the various Linux documentation sites using which I gathered this information.
* Matt Hoskins and Kevin Walsh, for getting me interested in Linux in the first place.
* My friends and family, for bearing with me when I was compiling this document.
1.3 Before you start
Before you attempt to change or replace the password of any machine, make sure you get permission from the management authorizing it, 'cause otherwise it can be mistaken as an attempt to hack into the machine, which is not good.
Secondly, create a backup of all important data before you do anything else, so if anything goes wrong you'll still have a copy of your data. If you didn't, and something went wrong, don't blame me. I tested most of this stuff on my system and it worked, but you are responsible for your system, not me, so don't blame me if something did go wrong.
2.1 Various Options available
There are various methods available for resetting a root password. In this section, I will list all the major ones, and we will go over each in detail later in the document. I will also go over some steps to prevent some other person from doing this and hacking your machine.
The various methods are:
* Boot into single-user mode (easiest, least risky)
* Boot using a boot disk and edit the password file
* Mount the drive on another computer and edit the password file
2.1.1 Reseting passwords by booting into single-user mode
This is the easiest and the fastest method to reset passwords. The steps are a little different depending on if you are using GRUB or LILO as a bootmanager.
Booting into single-user mode from LILO
Follow these steps to reset the password when using LILO:
* Reboot the system. When you see the LILO: prompt (see Fig. 1 below), type in linux single and press 'Enter'. This will log you in as root in single-user mode. If your system requires you to enter your root password to log in, then try linux init=/bin/bash instead.
* Once the system finishes booting, you will be logged in as root in single-user mode. Use passwd and choose a new password for root.
* Type reboot to reboot the system and then you can login with the new password you just selected.
Lilo Boot Menu
Figure 1. Lilo Boot Menu
If you have a new version of LILO which gives you a menu selection of the various kernels available press Tab to get the LILO: prompt and then proceed as shown above.
Booting into single user mode from GRUB
Follow these steps to reset the password when using GRUB:
* Reboot the system, and when you are at the selection prompt (See Fig. 2 below), highlight the line for Linux and press 'e'. You may only have 2 seconds to do this, so be quick.
* This will take you to another screen where you should select the entry that begins with 'kernel' and press 'e' again.
* Append ' single' to the end of that line (without the quotes). Make sure that there is a space between what's there and 'single'. If your system requires you to enter your root password to log into single-user mode, then append init=/bin/bash after 'single'. Hit 'Enter' to save the changes.
* Press 'b' to boot into Single User Mode.
* Once the system finishes booting, you will be logged in as root. Use passwd and choose a new password for root.
* Type reboot to reboot the system, and you can login with the new password you just selected.
GRUB boot screen
Fig. 2: GRUB Boot Screen
2.1.2 Reseting passwords by using a boot disk and editing the password file
This method is a little bit more complicated than the previous one and has a very high chance of success (assuming your filesystem is not encrypted and you didn't forget the password to decrypt it if it is). As before, get permission before you do this.
To start, you need a Linux boot disk or a rescue disk. (If you didn't create one when prompted during the installation then let this be a lesson for you.) You can use your installation CD as a rescue disk; most distros have an option to allow you to boot into rescue mode. With my Redhat Linux CD, I have to enter linux rescue to start the rescue mode. But this might be a bit different in each distro. You can also use a live linux CD like Knoppix or Gnoppix for system recovery. (Click here for a list of all the live Linux CD's). In this tutorial I will use Knoppix as my rescue CD but the process is almost the same for any rescue CD you might use.
[ You can also download one of the many single-floppy Linux distributions (e.g., Tom's RootBoot ), and use it to bring up the machine as described. This is, of course, much faster than downloading and burning a rescue CD, especially on a slow connection. - Ben ]
Follow these steps to reset the password using Knoppix:
* Reboot the system and configure it to boot from the Knoppix CD (instructions available here)
* At the Knoppix Boot Prompt (See Fig. 3 below) enter: knoppix lang=us to start boot Knoppix using the english locale. If you understand German, feel free to just hit 'Enter' to boot into Knoppix.
* Once the system finishes booting, press + + (The Control, Alt and F1 key together) to switch to a virtual terminal.
* Type mkdir mountplace to create a directory called 'mountplace'. This is where we will mount the filesystem.
* Type mount /dev/hdaX mountplace, where /dev/hdaX is your root partition. More information on Linux partitions is available here.
* Change to the "/etc" directory on your root partition by typing cd mountplace/etc.
* Use your favorite text editor and open the 'shadow' file for editing. I use 'vi', so I type vi shadow (If you have a really old system, you won't have a shadow file, in which case you need to edit the 'passwd' file.)
* Scroll down to the line containing the root user's information, which looks something like:
root:dsfDSDF!s:12581:0:99999:7:::
* Delete everything between the first and second colons, so that the line looks like:
root::12581:0:99999:7:::
* Save the file and exit your editor.
* Type cd to return to your home directory.
* Type umount mountplace to unmount the partition.
* Type reboot to reboot your system, and remove the Knoppix CD from the drive.
* Now you can log into your system as root with no password. Make sure you change the password immediately.
Knoppix boot screen
Fig. 3: Knoppix Boot Screen
2.1.2 Reseting passwords by mounting on another system and editing the password file
This option is a bit more work than any of the earlier options but is almost sure to work (except when the filesystem is encrypted).
Follow these steps to reset the password:
* Shut down the machine after backing up all important data.
* Open the casing, unplug the hard drive, and take it to another machine. (This system should be running Linux, since Windows can't read the Linux partition formats.)
* Connect the hard disk as a slave drive and boot the new system.
* Once the system finishes booting, mount the slave drive's root partition as shown above and edit the password file.
3.1 How to Prevent someone else from reseting your root password
If you are an even slightly security-consious sysadmin, the previous sections must have set off alarms while you were reading them. Is it really that easy to hack Linux? Yes and No. It all it comes down to the following: Physical Access is Root Access. Meaning, if you give someone physical access to a system, then you are giving them a very good chance of getting root access on your box. This is true for Windows, Linux, or any other OS out there.
But... you say that you need to give some people physical access to the server? There are some precautions you can take to slow down attackers and stop the noob's. In this section I will talk about various ways you can make your computer more secure against these types of attacks. So lets get started.
3.1.1 Password protecting GRUB and LILO
First, edit the /etc/inittab file and insert the following line, right after the "initdefault" line: ~~:S:wait:/sbin/sulogin. This will require a password to boot into single-user mode by making init run 'sulogin' before dropping the machine to a root shell. 'sulogin' requires the user to input the root password before continuing.
Unfortunately, the above step won't protect us against people who know what they are doing and pass init=/bin/bash to the kernel at the LILO prompt. To prevent unauthorized access I would suggest that you password protect LILO/GRUB by following these steps:
How to Protect LILO:
* Open a shell prompt and log in as root
* Open /etc/lilo.conf in your favorite text editor
* Add the following line before the first image stanza: password= , where is your password.
* Run /sbin/lilo -v to let the changes take effect
* Type chmod 600 /etc/lilo.conf to give only root access to read and edit the file since all passwords are in plain text
* Relax a bit, as your system is a little bit more secure
How to password-protect GRUB
* Open a shell prompt and log in as root
* Type /sbin/grub-md5-crypt and press enter
* Enter the password you chose for GRUB when prompted. This will return an MD5 hash of your password
* Open /boot/grub/grub.conf in your favorite text editor
* Add password -md5 below the timeout in the main section (Replace with the hash you got in the previous step)
* Save and exit
* The next time you reboot, the GRUB menu will not let you access the editor or command interface without first pressing [p] followed by the GRUB password.
3.1.2 Password-protecting the BIOS
There are two primary reasons for password-protecting the BIOS of a computer:
* Prevent Changes To BIOS Settings: if an intruder has access to the BIOS, they can set it to boot off of a diskette or CD-ROM.
* Prevent Booting the System: Some BIOSes allow you to password protect the boot process itself. When activated, an attacker would be forced to enter a password for the BIOS to launch the boot loader.
Because the methods for setting a BIOS password vary between computer manufacturers, you should consult the manual for your computer. If you forget the BIOS password, it can often be reset either with jumpers on the motherboard or by disconnecting the CMOS battery. However, you should check the manual for your computer or motherboard before attempting this procedure.
4.1 Conclusion
By now I have hopefully saved you a lot of trouble by telling you how to recover your root password and make it harder for others to get the password. If you think this document helped you, or you have some comments or questions about this please feel free to Contact Me and let me know. However I must warn you that I am a somewhat lazy person who might take a little while before replying to your emails.
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