Basic Linux Filesystems tutorial : ext2,ext3,ext4,JFS & XFS

The original Linux system used a simple filesystem that mimicked the functionality of the Unix filesystem. In this tutorial we will discuss basic file system used in Linux.

The ext Filesystem

The original filesystem introduced with the Linux operating system is called the extended filesystem (or just ext for short). It provides a basic Unix- like filesystem for Linux, using virtual directories to handle physical devices, and storing datain fixed-length blocks on the physical devices.

The ext filesystem uses a system called inodes to track information about the files stored in the virtual directory. The inode system creates a separate table on each physical device, called the inode table , to store the file information. Each stored file in the virtual directory has an entry in  the inode table. The extended part of the name comes from the additional data that it tracks on each file, which consists of:

• The file name
• The file size
• The owner of the file
• The group the file belongs to
• Access permissions for the file
• Pointers to each disk block that contains data from the file

Linux references each inode in the inode table using a unique number (called the inode number ), assigned by the filesystem as data files are created. The filesystem uses the inode number to identify the file rather than having to use the full file name and path.

The ext2 Filesystem

The original ext filesystem had quite a few limitations, such as limiting files to only 2GB in size. Not too long after Linux was first introduced, the ext filesystem was upgraded to create the second extended filesystem, called ext2 .

As you can guess, the ext2 filesystem is an expansion of the basic abilities of the ext filesystem, but maintains the same structure. The ext2  filesystem expands the inode table format to track additional information about each file on the system.

The ext2 inode table adds the created, modified, and last accessed time values for files to help system administrators track file access on the  system. The ext2 filesystem also increases the maximum file size allowed to 2TB (then in later versions of ext2, that was increased to 32TB) to help  accommodate large files commonly found in database servers.

In addition to expanding the inode table, the ext2 filesystem also changed the way in which files are stored in the data blocks. A common  problem with the ext filesystem was that as a file is written to the physical device, the blocks used to store the data tend to be scattered throughout the device (called fragmentation ). Fragmentation of data blocks can reduce the performance of the filesystem, as it takes longer to search the storage device to access all of the blocks for a specific file.

The ext2 filesystem helps reduce fragmentation by allocating disk blocks in groups when you save a file. By grouping the data blocks for a file, the filesystem doesn't have to search all over the physical device for the data blocks to read the file. The ext2 filesystem was the default filesystem used in Linux distributions for many years, but it, too, had its limitations. The inode table, while a  nice feature that allows the filesystem to track additional information about files, can cause problems that can be fatal to the system. Each time the filesystem stores or updates a file, it has to modify the inode table with the new information. The problem is that this isn't always a fluid action.

If something should happen to the computer system between the file being stored and the inode table being updated, the two would become out  of sync. The ext2 filesystem is notorious for easily becoming corrupted due to system crashes and power outages. Even if the file data is stored just  fine on the physical device, if the inode table entry wasn't completed, the ext2 filesystem wouldn't even know that the file existed!  It wasn't long before developers were exploring a different avenue of Linux filesystems. 

Journaling Filesystems

Journaling filesystems provide a new level of safety to the Linux system. Instead of writing data directly to the storage device and then updating the  inode table, journaling filesystems write file changes into a temporary file (called the journal ) first. After data is successfully written to the storage device and the inode table, the journal entry is deleted.

If the system should crash or suffer a power outage before the data can be written to the storage device, the journaling filesystem just reads through the journal file and processes any uncommitted data left over.

There are three different methods of journaling commonly used in Linux, each with different levels of protection. These are shown in  below Table.

Journaling Filesystem Methods

Method	Description
Data mode	Both inode and file data are journaled. Low risk of losing data, but poor performance.
Ordered mode	Only inode data written to the journal, but not removed until file data is successfully written. Good compromise between performance and safety.
Writeback mode	Only inode data written to the journal, no control over when the file data is written. Higher risk of losing data, but still better than not using journaling.

Limitation:

The data mode journaling method is by far the safest for protecting data, but it is also the slowest. All of the data written to a storage device must  be written twice, once to the journal, then again to the actual storage device. This can cause poor performance, especially for systems that do a lot  of data writing.  Over the years, a few different journaling filesystems have appeared in Linux. The following sections describe the popular Linux journaling  filesystems available.

The Extended Linux Journaling Filesystems

The same group that developed the ext and ext2 filesystems as part of the Linux project also created journaling versions of the filesystems. These journaling filesystems are compatible with the ext2 filesystem, and it's easy to convert back and forth between them. There are currently two  separate journaling filesystems based on the ext2 filesystem.

 

The ext3 Filesystem

The ext3 filesystem was added to the Linux kernel in 2001, and up until recently was the default filesystem used by just about all Linux distributions. It uses the same inode table structure as the ext2 filesystem, but adds a journal file to each storage device to journal the data written to the storage device.

By default, the ext3 filesystem uses the ordered mode method of journaling, only writing the inode information to the journal file, but not removing it until the data blocks have been successfully written to the storage device. You can change the journaling method used in the ext3 filesystem to either data or writeback modes with a simple command line option when creating the filesystem.

While the ext3 filesystem added basic journaling to the Linux filesystem, there were still a few things it lacked. For example, the ext3 filesystem doesn't provide any recovery from accidental deletion of files, there's no built-in data compressionavailable (although there is a patch that can be  installed separately that provides this feature), and the ext3 filesystem doesn't support encrypting files. For those reasons developers in the Linux project choose to continue work on improving the ext3 filesystem.

The ext4 Filesystem

The result of expanding the ext3 filesystem was (as you probably guessed) the ext4 filesystem. The ext4 filesystem was officially supported in the  Linux kernel in 2008, and is now the default filesystem used in most popular Linux distributions, such as Fedora and Ubuntu.

In addition to support compression and encryption, the ext4 filesystem also supports a feature called extents .Extents allocate space on a storage device in blocks, and only store the starting block location in the inode table. This helps save space in the inode table by not having to list all of the data blocks used to store data from the file.

The ext4 filesystem also incorporates block preallocation . If you want to reserve space on a storage device for a file that you know will grow in size, with the ext4 filesystem it's possible to allocate all of the expected blocks for the file, not just the blocks that physically exist. The ext4 filesystem fills in the reserved data blocks with zeroes, and knows not to allocate them for any other file.

The Reiser Filesystem

In 2001, Hans Reiser created the first journaling filesystem for Linux, called ReiserFS . The ReiserFS filesystem only supports writeback journaling mode, writing only the inode table data to the journal file. Because it writes only the inode table data to the journal, the ReiserFS filesystem is one of the fastest journaling filesystems in Linux.

Two interesting features incorporated into the ReiserFS filesystem are that you can resize an existing filesystem while it's still active, and that it uses a technique called tailpacking , which stuffs data from one file into empty space in a data block from another file. The active filesystem resizing feature is great if you have to expand an already created filesystem to accommodate more data.

The Journaled Filesystem(JFS)

Possibly one of the oldest journaling filesystems around, the Journaled File System (JFS) was developed by IBM in 1990 for its AIX flavor of Unix. However, it wasn't until its second version that it was ported to the Linux environment.

Note  :The official IBM name of the second version of the JFS filesystem is JFS2, but most Linux systems refer to it as just JFS.

The JFS filesystem uses the ordered journaling method, storing only the inode table data in the journal, but not removing it until the actual file data is written to the storage device. This method is a compromise between the speed of the ReiserFS and the integrity of the data mode journaling method.

The JFS filesystem uses extent-based file allocation, allocating a group of blocks for each file written to the storage device. This method provides for less fragmentation on the storage device. Outside of the IBM Linux offerings, the JFS filesystem isn't popularly used, but you may run into it in your Linux journey.

The XFS Filesystem

The XFS journaling filesystem is yet another filesystem originally created for a commercial Unix system that made its way into the Linux world. Silicon Graphics Incorporated (SGI) originally created XFS in 1994 for its commercial IRIX Unix system. It was released to the Linux environment for common use in 2002.

The XFS filesystem uses the writeback mode of journaling, which provides high performance but does introduce an amount of risk because the actual data isn't stored in the journal file. The XFS filesystem also allows online resizing of the filesystem, similar to the ReiserFS filesystem, except XFS filesystems can only be expanded and not shrunk.

Boot All The 5 Classic Ubuntu 14.04 Flavors From A Single Image, Via Ubuntu AIO

Hello Linux Geeksters. As you may know, Ubuntu AIO (all-in-one) DVD is an unofficial Ubuntu image that enables the users to use Ubuntu 14.04 in all its traditional flavors: Unity, GNOME, KDE, XFCE and LXDE, all from a single image.

In order to use Ubuntu AIO, you can either download the Ubuntu AIO Image and place it on an USB, or get all the five ISO images of the components (Ubuntu 14.04, Ubuntu GNOME 14.04, Kubuntu 14.04, Xubuntu 14.04 and Lubuntu 14.04) + the Ubuntu AIO component.

The users choose the Ubuntu flavor from the GRUB, but however, this does not work flawless. While Ubuntu, Kubuntu and Ubuntu GNOME are available only as 64 bit systems, while Xubuntu and Lubuntu are 32 bit systems.

Another drawback is the fact that Ubuntu AIO’s size is about 4.7 GB, so you will need an 8 GB USB stick to install it, from the Live Image.

As a reminder, Ubuntu 14.04 has been released on the 17th of April and is considered to be Canonical’s best release so far. Also, due to the fact that Ubuntu 13.04 and Ubuntu 12.10 have already reached EOL, while Ubuntu 13.10 has only a few months of support left, many users have migrated to Ubuntu 14.04.

Lubuntu is probably the lightest official flavor of Ubuntu and it’s based on LXDE. It’s been around for quite some time, and it is recommended for older systems.

Rubik's Cube

https://www.google.com/logos/2014/rubiks/rubiks.html
https://gstatic.com/logos/2014/rubiks/iframe/index.html

Supercharge your access to Android apps with 9 Cards

http://www.techrepublic.com/article/supercharge-your-access-to-android-apps-with-9-cards/

9 Cards is a unique home launcher that can help make you more efficient and productive in your interaction with Android. This isn't the standard home screen launcher (you can't select it as your default launcher). Instead, it runs as an app on top of your default home screen launcher to serve as an overlay and help you better organize your applications.

The truest beauty of 9 Cards is that, as you use the app, it adapts to your usage so you can locate your most used apps more easily. Here are some of the features you'll see with 9 Cards:

• Easy app organization
• Highly customizable
• Share your app collections
• Add apps to collections from 9 Cards curators
• Open with same gesture as Google Now
• Theme-able (you can even edit themes)

When you first install 9 Cards, things seem a bit odd. This is an app seemingly stuck between a home launcher and a full-screen dock. I like to think of it as a supercharged app drawer ready to take your Android experience to unheard levels of efficiency.

Let's install and start using 9 Cards.

Installation

9 Cards is free (though you can purchase an upgrade for $2.99 to get more features). As you've grown to expect, the installation for 9 Cards is simple. Just follow these steps:

1. Open the Google Play Store on your device
2. Search for 9 Cards
3. Locate and tap the 9 Cards entry by 47 Degrees LLC
4. Tap Install
5. Read the permissions listing
6. If you are okay with the permissions, tap Accept
7. Allow the installation to complete

As I mentioned earlier, this is not a replacement home screen launcher. You might expect, at this point, to tap your home button and be asked which launcher to use (as is the case when you install any new home screen launcher). With 9 Cards, you'll simply see an icon on your home screen. Tap that icon, and you're ready to go.

Usage

Upon first launch, you'll be walked through a lengthy instructional "wizard." During this process, you'll need to associate an account with 9 Cards. Your Gmail account will work fine. Select that account, and tap Continue. You'll then need to OK 9 Cards to have permission to access the Android Market. Swipe through that (gleaning as much information as you can), and you'll finally find yourself in the 9 Cards app (Figure A).

Figure A

9 Cards running on a Verizon-branded HTC M8.

What you see on the first page of 9 Cards is the Collections "cards" or tiles. Tap one of those, and you'll be taken to a listing of related apps (within that particular Collection). From there (Figure B), you can swipe to the right or left to view all of the other Collections.

Figure B

The Productivity Collection.

From within a Collection, you'll find installed apps and app recommendations. If you tap on a recommendation, it will open in the Google Play Store, where you can install it if desired. The more you use 9 Cards, the more intelligent it will get with its recommendations. This is an important feature of 9 Cards, as it makes finding apps that suit your needs a priority. You can also tap the plus sign [+] -- you may need to swipe all the way down, once in a Collection, to reach the Add New button -- to check out a listing of Recommendations (Figure C). You'll be pleasantly surprised at how many recommendations you'll get.

Figure C

App recommendations through 9 Cards.

You can also edit and rearrange the Collections tiles. To edit the tiles, tap the tiny overflow button in the top right corner of the tile you want to edit. This will bring up four icons (Share, Edit, Colors, and Delete). You can share a collection by tapping share, change the name of the collection by tapping edit, change the color of the tile by tapping Colors, and deleting the tile by tapping Delete.

To rearrange the tiles, long-press a tile and then drag it to the new location. This same method allows you to remove a Collection (long-press and then drag to Delete). New Collections can be added by swiping to the right and then tapping ADD NEW. You'll be prompted to select a Collection from the listing (Figure D).

Figure D

Listing of new Collections that you can add.

The nice thing about Collections is that they bring together related apps in one place. This means you don't have to endlessly search through the Google Play Store to find something that you need (that you might not know about).

You may add a Collection and have no related apps installed on your device, which is fine. Just search through the recommendations, and you'll find plenty of apps for installation.

Configuration

With 9 Cards you can customize:

• Animations
• Moments
• Personalization
• Actions

You can also apply new themes or edit the current theme. One of the first configurations you'll want to make is defining your home and work Wi-Fi networks. This will help 9 Cards learn what you do at each location. To define these networks, do the following:

1. From the 9 Cards main window, tap the overflow menu
2. Tap Settings
3. Tap Moments
4. Tap Home (Figure E)
5. Select your home wireless network
6. Tap Work
7. Select your work wireless network
8. Tap the device Back button to return to Settings

Figure E

Defining your Home and Work networks for 9 Cards.

At this point, it's a matter of using 9 Cards to allow it to get to know your habits.

I've found 9 Cards to be an outstanding means of working productively with an Android device. By arranging your apps and helping you find new apps, you'll feel like you've become a machine of efficiency.

How Addicted Are You to Your Phone?

A revolutionary mobile app aimed at controlling smartphone addiction and helping you maintain a healthy digital lifestyle.

http://www.breakfree-app.com/

Are you Addicted?

How many times a day do you think you check your phone? Once every hour? Once every 30 minutes? You most likely are wrong. Study shows that an average adult checks his phone a whooping 110 times a day. That makes it once every 13 minutes. And for most people this peaks to once every 6 seconds in the evenings. So if you, like most people, are checking your phone when you could be spending time with a real human being, or doing something constructive, then BreakFree is for you. 

BreakFree is a revolutionary app that will help you maintain a controlled digital lifestyle. It monitors phone and app usage and tracks how addicted you are to your phone and apps. With visually appealing characters, graphs and stats, the app guides you on how you can control phone usage.

Send faxes with your Android device

http://www.techrepublic.com/article/pro-tip-send-faxes-with-your-android-device/#ftag=RSS56d97e7

As much as I think the fax technology should finally give up the ghost, it will probably last longer than I do. The fax is as ingrained into the world of business as the company meeting, middle-management, and khaki. But just because your company (and other companies) make use of ancient technology doesn't mean you can't work with that technology using your modern devices.

Thanks to a free app called FaxFile, you can now send either PDF or doc/docx files to any fax number in the US or Canada (and some international numbers). With FaxFile, you can fax to contact numbers or enter a fax phone number. There isn't a monthly subscription cost, but each fax will cost you fax credits (which are bought through an in-app purchase within the Google Play Store). Fifty credits is $2.49, and each fax to US and Canada costs 10 credits. That's pretty easy math and well worth the cost, considering how easy faxing becomes while on-the-go.

Let's install FaxFile and put it to use.

Installation

As you might expect, installing FaxFile is quite easy. Just follow these simple steps:

1. Open the Google Play Store on the device
2. Search for FaxFile
3. Locate and tap the entry by Actual Software Inc.
4. Tap Install
5. Read through the permissions listing
6. If you're okay with the permissions, tap Accept
7. Allow the installation to complete

Once it's installed, tap the launcher on the home screen (or from within the app drawer) and read through the intro.

Usage

FileFax works like so:

1. From the main window (Figure A), add at least one document
2. Tap Recipient Fax to manually enter the Fax number or tap the pick contact button and select the recipient from your contacts
3. Tap the continue button

Figure A

FaxFile running on A Verizon-branded HTC M8.

At this point, you may receive a message that the chosen contact is not labeled as a fax number. You are given two choices: 1) Return to setup or 2) Send the fax. If you tap Send the fax, you'll then be prompted to add your name and your Fax/Phone number (Figure B).

Figure B

Including your name with the fax.

To complete the fax process, you must now buy credits. In the next window (Figure C), tap Buy Credits and walk through the purchase. After this step, the Send button will be made available and you can tap it to send your fax.

Figure C

Time to purchase credits for sending faxes.

You can also buy credits by tapping the overflow menu button and selecting Buy Credits. From that same menu, you can access your Billing History, view the Status Screen, and look at International Rates.

If you happen to need a cover page, you can add one one by following these steps:

1. From the main window, tap the overflow menu button
2. Tap Add Cover Page
3. If prompted, tap Install for FaxCover (this is also free)
4. Walk through the process of installing FaxCover (if necessary)
5. Enter the desired information for the cover page (Figure D)
6. Tap Continue
7. Proof the cover page
8. If the page is good, tap Save

Figure D

Entering information for a cover page.

After the cover page is saved, it will show up in the file listing for the fax as a .pdf document.

If you're looking for one of the easiest means of faxing word documents, PDFs, and images on the go, then look no further than FaxFile. For those who still cling to ancient faxing technology, this handy app can really simplify your modern on-the-go life.

Pro tip: How to work with Google Docs offline using Android

http://www.techrepublic.com/article/pro-tip-how-to-work-with-google-docs-offline-using-android/#ftag=RSS56d97e7

When you're a road warrior without a consistent, reliable connection for your device, how do you work with your Google Drive documents? Simple -- you install Google Docs and Google Sheets on your Android device and make them available offline. Of course, it's not quite that straightforward. Fear not, all of the instructions you need for this process are here. After going through this post, you should be working with documents, sans a network connection, like a champ.

What you'll need

Here are the requirements:

• An Android device (preferably updated to the latest release available)
• Google Docs and Google Sheets installed
• Your Android device associated with your Google Drive account

Installation

If you don't already have Docs and Sheets installed, here are the steps:

1. Open the Google Play Store on your Android device
2. Search for Google Docs
3. Locate and tap the official Google app
4. Tap Install
5. Read through the permissions listing
6. If you agree with the permissions listing, tap Accept
7. Allow the installation to complete

Repeat the above steps for Google Sheets.

Once you have everything installed, it's time to start working with a document offline.

Usage

Because of the cloud-nature of Google Drive, all of your documents are not automatically available offline. In fact, you have to manually configure each document you want to use offline -- so, this is best done on a per-document basis. Of course, you'll want to make sure to set those documents for offline use before you need them. Should you find yourself without a connection and needing one of those documents, you'll be out of luck.

With that said, here's how you configure a document for offline usage.

1. Open up the app to be used (either Sheets or Docs)
2. Locate the file to be used offline in the file listing (Figure A)
   Figure A
   

   

3. Tap the information icon (on the far right) associated with the file
4. In the resulting window (Figure B), switch Keep on this device to ON by tapping the slider
   Figure B
   

   

The file is now available for offline usage. In order to open the file to edit offline, do the following:

1. Tap the overflow menu in the upper left corner
2. From the resulting sidebar (Figure C), tap On device
   Figure C
   

   

3. From the listing of documents, tap the document to be edited
4. Edit away

If you need to remove a document for offline editing, do the following:

1. Go to the file listing in the app (either Sheets or Docs)
2. Tap the information button associated with the file
3. Tap the Keep on this device slider until it is in the OFF position

Naturally, you can edit any document while connected to either 4G (3G, etc) or Wi-Fi. But when you do not have that connection available, the only means to edit files is when they're stored on your device. After you've edited those offline documents, the moment the device is back online, the changes will sync with your Google Drive account (there's no need to manually re-sync).

Editing Google Documents offline is not a difficult task -- you just have to get use to making the necessary documents available for offline usage.

What do you think? Is this system a workable solution? Or does Google need to rethink how documents are managed when a device is offline?

Your Linkedin personal brand: 6 tips to build a strong one

http://www.techrepublic.com/article/your-linkedin-personal-brand-6-tips-to-build-a-strong-one/#.

LinkedIn is more than a place to dump your resume and split. Here are some tips to build your image on world's largest professional network. 

As a professional, people will search you.

"When someone is looking for you, there are a couple of places they go. First, they might start in LinkedIn directly... Or, they might search Google for your name -- which will likely also lead them to LinkedIn," said Hubspot founder and CTO Dharmesh Shah. "Either way, it's the de facto place people expect to find you."

That means making a little effort to make sure that your image is looking sharp on the largest social media platform for business professionals would be a wise move. Keep in mind that Linkedin is no longer about just finding a new job. It's also a place where colleagues and potential business partners and customers can look you up and connect with you.

"The most important thing to remember is that unlike other social-media sites where stupidity and silliness may be forgiven if not downright condoned, LinkedIn is all about your personal brand," said Canva's chief evangelist, and LinkedIn Influencer Guy Kawasaki.

So, save your cat pictures for Facebook, and leave the mayfair-filtered ham sandwiches on Instagram.

Here are some more tips on building and maintaining a strong personal brand on LinkedIn.

1. Have a complete profile

Each chance to fill out a piece of your professional image - where you went to school, where you've worked - offers the chance to show what you could do in the future, said Shah, who is also a LinkedIn Influencer. Completing your LinkedIn might sound obvious, but Gartner analyst Jennifer Polk said there are still plenty of professionals who haven't even uploaded a profile picture.

"Completing the LinkedIn profile is one of those things that requires one-time effort - but provides gains on an ongoing basis. There are not that many things in life like that - take advantage of them," Shah said.

2. Treat LinkedIn like more than just a resume

Though the initial step in creating a LinkedIn is to enter resume-style information, that doesn't mean users can post a CV and walk away. Polk said to treat it more like a synopsis of who you are and what you do. Also, because the platform is relationship-driven, she said it's important to remember that other professionals use it scope you out. "It's an individual one-to-one system for vetting people you're doing business with," Polk said.

3. Watch your opinions

Think about what you post on LinkedIn in terms of what would be safe and appropriate to say in a workplace, or to an employer. "Obviously, folks should avoid expressing beliefs such as women should not have equal rights--don't laugh, I've seen this done," Kawasaki said. "The general mindset that's necessary is, 'Don't say or do anything that you wouldn't do in a job interview for a job that you want.' Every post and every comment is like a job-interview question on LinkedIn." When you post, be professional.

4. Be active

"You wouldn't not answer your desk phone," Polk said. Keeping up with and responding to things like InMail, comments, or requests show that you've actively engaged with your LinkedIn profile, and well as the wider community.

5. Add value, not ridiculousness

You can now post updates on LinkedIn, similar to Twitter and Facebook, but be wise about doing it. According to Kawasaki, adding value to LinkedIn comes in three forms: information, analysis, and assistance. This is a good trio to keep in mind when deciding what to post. "If you want to act stupid, do it somewhere else. Instead, you should always be adding value to people's feeds to build a good personal brand on LinkedIn," he said.

Shah said by sharing useful content, you're making sure people understand your areas of interest and expertise. And if you're looking for a source for content to share, he suggested following LinkedIn's Influencers.

6. Don't indiscriminately amass followers

Speaking of followers, Shah thinks that one of the biggest mistakes users make on LinkedIn is trying to rack up as many connections as possible. "What it does is makes both an individual's social graph and the overall network as a whole noisy and thereby less useful," he said. Shah connects with people with whom he has worked, or at least who are in his circle of associates- they're actual intersections. "Your connections are a reflection of you," he said.

How to find a reliable network speed test

http://www.cnet.com/how-to/how-to-find-a-reliable-network-speed-test/?ttag=fbwl


SpeedOf.me and TestMy.net  and SpeedCheck.org

Your ISP may be delivering slower download and upload speeds than it promised when you signed up, but wide variations in test results could leave you scratching your head.

SpeedOf.me's HTML5-based network speed test recorded the fastest download rate of dozens of tests run at different testing sites.Screenshot by Dennis O'Reilly/CNET

Are you getting all the network bandwidth you're paying for? Good luck trying to find out.

As Rani Molla reported recently in the Wall Street Journal, some ISPs are delivering download speeds up to 41 percent slower than they advertise. The figures were compiled by speed-test service Ookla, which owns Speedtest.net.

According to Ookla's figures, the folks in Idaho Falls, Idaho, realize only half the download speed their ISPs claim to provide. Internet users in London, Ky.; Huntington, W. Va.; and Odessa, Texas, don't fare much better: all receive information over their network at speeds far below what their ISPs promise.

The slowest download speed test result from DSLReports.com was a fraction of the rate promised by my ISP.Screenshot by Dennis O'Reilly/CNET

Rerunning the DSLReports.com download speed test generated a result more than 10 times faster than earlier tests.Screenshot by Dennis O'Reilly/CNET

When I tested more than a half-dozen network speed calculators, the results varied by a factor greater than 10: the lowest reported download speed was a snail's-pace 783Kbps usingDSLReport.com's Flash-based test. Another test using the same service resulted in a download speed reading of 11.237Mbps.

The highest download speed test result I recorded was 13.06Mbps using the HTML5-based test at SpeedOf.me (shown at the top of this post). However, the same test generated a download speed of 4.87Mbps on the connection two days later.

(For the record, my ISP promises download speeds up to 12Mbps. I ran the tests in both Firefoxand Google Chrome on a Windows 8.1 laptop; many of the services also test phone network speeds, but I didn't run any of them.)

A subsequent download speed test at SpeedOf.me recorded a much slower rate than a test conducted days earlier.Screenshot by Dennis O'Reilly/CNET

Conversely, the results of the upload tests at the various services were consistently at or just under 2Mbps. The exceptions were upload-test results at DSLReports.com, whose testing was so inconsistent I ended up discarding all of the service's results.

I ran the tests at DSLReports.com about a dozen times: three times the download results were under 1Mbps, five times they were between 1Mbps and 4Mbps, twice they were around 8Mbps, and three times the download speed the test reported topped 10Mbps.

Does the type of speed test make a difference?

Many experts claim HTML5-based speed tests are more accurate than tests that use Java and Adobe Flash. Others point out that multithread tests such as those used by Ookla (Speedtest.net and branded by many ISPs) don't represent real-world network traffic as well as single-thread tests.

The most consistent test results were recorded at Speakeasy's Flash-based Speed Test and atTestMy.net's HTML5-based tester. Of course, the services' tests may be consistently wrong. After running several tests over a span of days, all of Speed Test's download results were within a few kilobits of 11.5Mbps. TestMy.net's download scores in both its single- and multithread tests exhibited a bit more range than those of Speakeasy's Speed Test, but they averaged about 11.2Mbps.

The results of the HTML5-based speed tests conducted at Bandwidth Place ranged from 5Mbps to 11Mbps, those at Toast.net exhibited a similar range, and the Flash-based tests at ZDNet's Broadband Speed Test recorded speeds from 5.8Mbps to 11.4Mbps.

Not surprisingly, the highest consistent speeds were reported when I ran the tests offered by my ISP, AT&T. The company's speed tests are provided by Ookla, as are the tests at many other network providers. (Note that the Java-based network tester at the FCC's Broadband.gov runs on the Measurement Labs platform, which doesn't support the Safari, Google Chrome, or Opera browsers. The FCC's test also requires that you supply your street address.)

With only one exception, all the download tests I ran at theAT&T Internet Speed Test and at Ookla's Speedtest.net indicated speeds of 11.5Mbps or greater. One of the dozen-or-so tests recorded a download speed of 10.4Mbps, and several of Ookla's Flash-based test results exceeded 12.5Mbps for downloads.

After conducting more than 100 network speed tests from many different providers over the course of several days, I'm confident my ISP is delivering speeds approximating -- and perhaps exceeding -- those it promised when I signed up for the service. Whether any of the speed tests I tried truly represent real-world network traffic is debatable.

HTML5-based speed tests such as those offered by SpeedOf.me and TestMy.net seem to have an advantage in that they require no additional software. If you suspect you're paying for more bandwidth than you're actually getting, you needn't trust your ISP's test results to make your case -- especially if you happen to live in one of your service's dead zones. Hello, Pocatello!

SpeedCheck.org

The internet speed test is your go-to tool that will help you through the process of measuring and troubleshooting your internet speed. The speed test can tell you the exact speeds that you’re getting at a particular time, which is the first step in telling what issues may be affecting your internet. Performing speed tests is easy with Speedcheck, and the records of each test you perform will be conveniently stored so you can review them all later.

Life In 4K (ULTRA HD)

4K VIDEOS

https://www.youtube.com/playlist?list=PLD33E5618740295DF

ULTRA HD VIDEOS

https://www.youtube.com/watch?v=xDMP3i36naA&list=PLbpi6ZahtOH6qU1WZzpcYz6hPhPRMByo8

The Best Book "Learning Nagios 4"

"The Best Book to Learn Nagios 4"

http://www.packtpub.com/learning-nagios-4/book

 

This book will introduce Nagios to readers who are interested in monitoring their systems. All the concepts in the book are explained in a simplified manner, presented in an easy-to-understand language with lots of tips, tricks, and illustrations.

This book is great for system administrators interested in using Nagios to monitor their systems. It will also help professionals who have already worked with earlier versions of Nagios to understand the new features of Nagios 4 and provides usable solutions to real-life problems related to Nagios administration. To effectively use this book, system administration knowledge is required. If you want to create your own plug-ins, knowledge of scripting languages like Perl, shell and Python is expected.

The following topics covered in this Book

·  Install and configure Nagios to administer your network and system

·  Deploy agents and plug-ins, and monitor assets with advanced features of Nagios

·  Notify users of current and future incidents to protect the availability, performance, and security of monitored assets

·  Configure and work your way around the Nagios web interface

·  Pass service and host check results over the network using NSCA

·  Set up a working and usable distributed monitoring system using NSClient++

·  Develop custom plug-ins responsible for performing checks and analyzing results

·  Use the web interface to manage scheduled downtimes for hosts and services

·  Implement adaptive monitoring to modify various check-related parameters

·  Make use of SSH and NRPE to perform remote checks

·  Use SNMP to retrieve information from a device, set options, and also cover means for a device to notify other machines about a failure.

IT Centre Police Head Quarter

Delhi Traffic Police
https://play.google.com/store/apps/details?id=com.coralsoftech.ucbpms.delhitrafficpolice

This Delhi Traffic Police Application aims at increasing public engagements and providing them with easy access to information about traffic situation in Delhi.

The vision is to enable public to avail information about traffic and to utilize e- services provided by Delhi Traffic Police in future. Currently the services provided included:-

+ Information about traffic alerts and advisories.

+ Fare and distance calculator while using auto-rickshaw, taxi and radio cab

+ Lodging complaints against autos, taxi in case of harassment, overcharging and misbehave.

+ Locating nearest pit for vehicles towed away by Traffic police when parked illegally.

+ Direct calls to emergency numbers in case of exigency.

+ FAQ about Delhi Traffic Police and the provided services.

Delhi Police Lost Report

https://play.google.com/store/apps/details?id=com.pcsolutions.delhipolice.lr

This mobile application facilitates hassle free lodging of report with Delhi Police for article/document lost in Delhi

The complainant has to provide the following details :

+ Complainant's Name, Father's/Mother's Name, Address, Mobile No, Email ID,Place of Loss in Delhi, Date of Loss, Time of loss (optional)

+ Lost Article(s) with Description (upto 10)

+ Brief of complaint.

+ On lodging of Lost Report (after clicking register button), complainant will get LR no. and other details prompt of lodging the report with Delhi Police with option of View/Download and Save/Exit.

+ In case saved, complainant can retrieve it in future by clicking the retrieve button.

+ On prompt complainant will also get link to generate and view the report.

Any agency or an individual has an option to verify the authenticity of the report, by entering the LR no by visiting the website of Delhi Police i.e. http://delhipolice.nic.in

To Access this application, users should have proper data / WiFi connection to

How to use Google Maps offline mode on iOS, Android

http://www.cnet.com/how-to/how-to-use-google-maps-offline-on-ios-android/?ttag=fbwl

When Google revamped the look of Google Maps for iOS and Android, users were upset about the lack of traditional features. Some users were so upset, the option of reverting to a much older versionof the app was the answer.

With Google's announcement today, Google Maps is finally starting to gain some of the beloved features that were once left out. One such feature is proper Offline Mode. While there was a method forcaching offline maps in prior versions of Google Maps, it was less than intuitive.

The new version streamlines the process of not only saving a section for offline use, but for accessing said sections later when you're without a connection.

The process is identical on both iOS and Android.

• First, you'll need to install the update. The iOS version is now at 3.0, while Android is at 8.0. Android users who aren't seeing the update right away should keep checking back. Google likes to slowly release Android updates.

Screenshot by Jason Cipriani/CNET

• Once you have the updated version, launch the app and tap on the profile icon located next to the search bar. Then scroll to the bottom of the page.

Screenshot by Jason Cipriani/CNET

• There'll you'll find a new section dedicated solely to offline maps. You have two methods for saving a section for offline use. The first is here in the settings, or by typing "OK Maps" into the search bar at any time when viewing a map.

Screenshot by Jason Cipriani/CNET

• After activating the save dialogue, you're able to zoom in and out of an area and save it to your device. If the area is too large, you'll be asked you zoom in, name the area, and save it.

Keep in mind any saved maps will only remain on your device for 30 days. Presumably, after that the app will purge a saved map to clear up space on your device.

Technologies to Refer

VSIFax
Subversion
Information Risk Management (IRM)
Java Legacy Security
WMS - Direct Fulfillment (DF)
Openmake
Jenkins
Application Architecture (AA)
Tivoli Storage Manager (TSM)
Labor Management - Store Labor
Teradata
Content Segment - Grid
Documentum
Symantec CSP
ClearCase
OSE - Datacenter Unix Engineering Server
Appl_Log
Puppet
Cassandra
Hadoop
MQ
RDC Canada
Statistical Analysis Software (SAS)
Spacewalk
SAP SCORE
Warehouse Management System (WMS)
FlexPLM
Tivoli Workload Scheduler (TWS)
SAP SCORE BW
Labor Management WMS
Netflow Collectors

Say the Time

Manage your time better than ever before. Say the Time will keep you on schedule by automatically announcing the date, time or both at specified intervals using a pleasant male or female voice. Keep track of important time commitments with fully-customizable appointment reminders. Manage ideas and information with colorful virtual sticky notes. Transform your boring taskbar time display into a colorful clock that can display both the date and the time. View the time in different parts of the world.

http://www.saythetime.com/

https://www.youtube.com/watch?v=eKN3VXQ4Vb8