This Blog is intended to collect information of my various Intrests,pen my opinion on the information gathered and not intended to educate any one of the information posted,but are most welcome to share there view on them
Thursday, August 21, 2014
Friday, August 15, 2014
Monday, August 11, 2014
Thursday, August 7, 2014
Thursday, July 3, 2014
How to Remove Write Protection of any Flash Drives/Memory Cards
http://way2usefulinfo.blogspot.com/2014/07/how-to-remove-write-protection-of-any.html
In olden days we had lesser ways to store data, as technology advanced we got Floppy disk, Optical Disk and now flash drives, they are easily vulnerable as they can accessed by anyone, but flash drives had the feature to secure them from spammers
We can add Write protection so that no one can use it , the person who owns only can access it , this is good for security reasons, sometimes we need to remove those protection for some fair reasons, i will teach you the easy possible way which you can easily Remove write protection on any Flash Drives/ Memory cards
HOW TO REMOVE WRITE PROTECTION OF ANY FLASH DRIVES/ MEMORY CARDS
1) TRY LOW LEVEL FORMATTING
In olden days we had lesser ways to store data, as technology advanced we got Floppy disk, Optical Disk and now flash drives, they are easily vulnerable as they can accessed by anyone, but flash drives had the feature to secure them from spammers
We can add Write protection so that no one can use it , the person who owns only can access it , this is good for security reasons, sometimes we need to remove those protection for some fair reasons, i will teach you the easy possible way which you can easily Remove write protection on any Flash Drives/ Memory cards
HOW TO REMOVE WRITE PROTECTION OF ANY FLASH DRIVES/ MEMORY CARDS
1) TRY LOW LEVEL FORMATTING
- We cannot use the default windows method, so you need to download one special tool which is given here LOW LEVEL FORMATTING
- Format the Password protected Pen Drive with this Tool
- Now open the Run box ( Win+R) and type diskmgmt.msc in Box
- You can see your Pen Drive, Flash the Drive and allocate the Space
- There will be no error after you Allocated the Space to Flash Drive
2) Modify Registry Settings
- Before doing things on Registry, please do backup of Registry
- Open the Run box ( Win+R) and type regedit in the box
- Search for the Following Registry Key in the Window
Monday, June 23, 2014
Top 10 Cloud Computing Certifications
http://www.cio.com/slideshow/detail/129043#slide10
As the cloud becomes more critical to IT departments and businesses worldwide, it can be difficult to gauge whether you have the right skills or knowledge in a competitive job market. If you're looking for a way to get an extra edge -- whether you're job hunting, angling for a promotion, or just want tangible, third-party proof of your skills -- cloud certification is a great option. Certifications measure your knowledge and skills against industry- and vendor-specific benchmarks to prove to employers that you have the right mix of cloud skills, knowledge, and expertise. Here 10 ten cloud computing certifications you should consider.
As the cloud becomes more critical to IT departments and businesses worldwide, it can be difficult to gauge whether you have the right skills or knowledge in a competitive job market. If you're looking for a way to get an extra edge -- whether you're job hunting, angling for a promotion, or just want tangible, third-party proof of your skills -- cloud certification is a great option. Certifications measure your knowledge and skills against industry- and vendor-specific benchmarks to prove to employers that you have the right mix of cloud skills, knowledge, and expertise. Here 10 ten cloud computing certifications you should consider.
1. CCSK -- Cloud Security Alliance
What it's all about: This is the mother of all cloud computing security certifications. The Certificate of Cloud Security Knowledge certification is vendor-neutral, and certifies competency in key cloud security areas. The test is based on the Cloud Security Alliance Security Guidance for Critical Areas of Focus in Cloud Computing V3, English language version, and the ENISA report "Cloud Computing: Benefits, Risks and Recommendations for Information Security."
How to prepare: The best way to prepare is to study the CSA Security Guidance for Critical Areas of Focus in Cloud Computing v3, and the ENISA report "Cloud Computing: Benefits, Risks, and Recommendations for Information Security."
More on CSA Guidance
More on ENISA
More on ENISA
2. Cloud U -- Rackspace
What it's all about: According to Rackspace, Cloud U is a vendor-neutral curriculum designed for IT professionals and business leaders that covers and certifies knowledge of the fundamentals of Cloud Computing. Cloud U content is available to any professional at any time, but if you want a formal recognition of your knowledge about Cloud Computing, you should complete the courses and requirements for a certificate.
How to prepare: Study each Cloud U lesson whitepaper, and then successfully complete each of 10 Cloud U lesson quizzes based on the whitepaper's content. Successfully complete a 50-question final exam drawn from materials covered in the 10 Cloud U lessons.
More on Cloud U
3. CompTIA Cloud Essentials -- Comp TIA
What it's all about: According to CompTIA, the Cloud Essentials Certification covers the basic fundamentals of cloud computing and shows that individuals understand cloud computing from both a business and a technical perspective. In addition, the certification covers migration to the cloud and governance of cloud computing environments.
How to prepare: CompTIA offers study and training materials, and -- while it's not required -- CompTIA recommends that individuals taking the exam have at least six months experience working in an IT services environment.
More on CompTIA Cloud Essentials
4. Cloud Certified Professional -- CloudSchool.com
What it's all about: CloudSchool.com offers a number of vendor-neutral cloud certifications, each based on a one-day course module and aimed at competency in specific areas of cloud computing. There are certificates for Cloud Architects, Cloud Technology Professionals, Cloud Governance, and Cloud security, among others.
How to prepare: Cloud School offers self-study kits as well as on-site and remote workshops and study sessions and instructor-led workshops to help prepare applicants for the exams.
More on CloudSchool.com
5 & 6. IBM Certified Cloud Solution Architect v1 and v3 - IBM
What it's all about: IBM has two cloud-specific certification: IBM Certified Solution Architect v1 and v3. These solutions architects will demonstrate the design, plan, architecture and management capabilities for IBM's cloud computing infrastructure once they've completed the certification requirements. According to IBM, these certifications, "Provide a reliable, valid and fair method of assessing skills and knowledge; provide IBM a method of building and validating the skills of individuals and organizations; and to develop a loyal community of highly skilled certified professionals."
How to prepare: You should have a working knowledge of cloud fundamentals and a basic knowledge of IBM cloud computing essentials. You will be required to take a test to confirm that knowledge for each version of the certification exam.
More on IBM Certifications
7. Google Certified Deployment Specialist -- Google
What it's all about: This is Google's technical certification; the applications giant also has a Google Certified Sales Specialist. This certification covers the fundamental skills, knowledge and technical expertise required to deploy Google Apps for Business and Education, according to Google.
How to prepare: Google recommends gaining practical experience by participating in at least three Google Apps for Business deployments, and having at least 3 to 6 years of hands-on IT experience. You'll also complete hands-on, online, self-paced training and, finally, take an exam.
8. Salesforce.com Certified Professional -- Salesforce.com
What it's all about: Salesforce.com offers several certification tracks, including Salesforce Administrator, Force.com Developer, Implementation Expert, and Architect.
How to prepare: According to Salesforce.com, the certification tests real-world knowledge as much as book learning, and each certification track offers a variety of ways to prepare for the exams. There are individualized programs available for everyone available on the company's web site.
9. VMware Certified Professional - VMware
What it's all about: The virtualization pioneer offers six cloud-specific certifications, from beginner to advanced. These tracks certify knowledge and expertise in a variety of cloud and virtualization-related technologies and methodologies. Offerings include the VMware Certified Associate -- Cloud, VMware Certified Professional -- Cloud, and VMware Certified Advanced Professional, among others.
How to prepare: Study and preparation materials are available through VMware, and real-world experience with cloud and virtualization are also highly recommended.
More on VMware Certified Professional
10. Red Hat Certificate of Expertise in Infrastructure-as-a-Service -- Red Hat
What it's all about: This is one of the newest cloud certifications available. The Red Hat Certificate measures professionals' ability to design, build, deploy and manage private clouds based on the Red Hat Enterprise Linux OpenStack platform.
How to prepare: Red Hat says the best way to prepare for the exam is hands-on, real-world experience. The exam is also a live, real- world test of skills and competency, requiring candidates to perform tasks on a live system.
More on Red Hat Certificate of Expertise
Monday, June 9, 2014
Wednesday, June 4, 2014
Google Transparency Report :- Saferemail
If you’re sending confidential information by mail, you wouldn’t put it in a postcard. Find out how secure your email is in a new section of our Transparency Report:
http://www.google.com/transparencyreport/saferemail/

http://www.google.com/transparencyreport/saferemail/

Saturday, May 24, 2014
Google picks up incredible visual translation app Word Lens and makes it free
Word Lens Translator
https://play.google.com/store/apps/details?id=com.questvisual.wordlens.demo
https://itunes.apple.com/us/app/word-lens/id383463868
https://play.google.com/store/apps/details?id=com.questvisual.wordlens.demo
https://itunes.apple.com/us/app/word-lens/id383463868
Description
Instantly translate printed words with your phone’s camera!
Word Lens gives you translation on the go:
- NO NETWORK required - results appear immediately on your video screen when you need it, anywhere in the world.
- Easy to use, like the regular camera
- Look up translations by typing them in, or clicking on a word.
- NO NETWORK required - results appear immediately on your video screen when you need it, anywhere in the world.
- Easy to use, like the regular camera
- Look up translations by typing them in, or clicking on a word.
Available language pairs:
+ English ⇆ Russian
+ English ⇆ Spanish
+ English ⇆ French
+ English ⇆ Italian
+ English ⇆ German
+ English ⇆ Portuguese
+ English ⇆ Russian
+ English ⇆ Spanish
+ English ⇆ French
+ English ⇆ Italian
+ English ⇆ German
+ English ⇆ Portuguese
Notes for getting the best quality out of your translations:
- Best used on clearly printed text (e.g. signs, menus)
- DOES NOT recognize handwriting or stylized fonts
- It's not perfect, but you can get the general meaning!
- Keep text in focus by holding it at least one hand-length away and tap-to-focus if autofocus is struggling.
- Turn on the flashlight (if available on your device)
- Zoom in (if available on your device)
- Best used on clearly printed text (e.g. signs, menus)
- DOES NOT recognize handwriting or stylized fonts
- It's not perfect, but you can get the general meaning!
- Keep text in focus by holding it at least one hand-length away and tap-to-focus if autofocus is struggling.
- Turn on the flashlight (if available on your device)
- Zoom in (if available on your device)
Some features are device dependent. Not all device cameras can zoom, nor do all devices have a flashlight.
Friday, May 23, 2014
The top 10 programming skills that will get you hired
SQL
Most businesses and websites have databases that work behind the scenes and many of those databases rely on SQL. Structured Query Language is what is referred to as a specialized programming language in that it was designed for editing and querying data residing in relational database management systems.
Java
Java's write-once-and-run-anywhere mantra says it all. This cross-platform, object-oriented programming language has become one of the most sought-after programming skills in the developer world. It's been around since 1995 and is still one of the most popular languages from a developer and an employer perspective.
HTML
HTML is one of the fundamental technologies that the Web is built upon. When combined with JavaScript and CSS, you can use HTML to create impressive Web pages and apps with interactive features like geolocation capabilities, better forms, video and canvas capabilities, and Web storage. Add CSS and jQuery to the mix, and you've got one of the hottest design paradigms right now: Responsive design. These features will help developers and businesses better engage with their customers.
JavaScript
JavaScript, like HTML is a part of the fabric of the Web. It's been around forever, but it has recently shown resurgence with the jQuery libraries. It's used in pretty much every Web browser to make Web pages more interactive among other things.
C++
C++, developed by Bjarne Strousup in 1983, is an enhancement of the programming language C. The addition of object-oriented programming has given this high-level language some low-level capabilities, making it a good multi-purpose language capable of building standalone applications as well as reusable code.
C#
Object-oriented C# (pronounced "C Sharp") was developed by Microsoft as a multi-paradigm programming language that is fully compatible with Microsoft's .Net schema. Although it's used mainly on Windows, C# is designed as a cross-platform language.
XML
Extensible Markup Language, or XML, is a markup language used to define document encoding that has gone on to become the default for many office productivity suites. Where HTML is about how information is displayed, XML is about transporting and storing data. The format is such that the code is readable by both humans and machines.
C
C is arguably the most widely used and currently the most popular programming language, according to the Tiobe Programming Community Index. A host of other programming languages have borrowed from this general purpose language including, C#, Python, Java, PHP, and Perl.
Perl
Larry Wall created Perl in 1987; it originally got its start as a general purpose Unix scripting language. It has a hodgepodge of features from C, shell script, AWK, and sed that is designed to allow developers to work more easily with text data.
Python
Python is high-level object-oriented programming language that developers can use in many ways. Python is all about readability. Its uniform and streamlined syntax allows programmers to build concepts more quickly and with less code.
Replacing physical tools with free smartphone apps
Genius Scan - PDF Scanner
https://play.google.com/store/apps/details?id=com.thegrizzlylabs.geniusscan.free
https://itunes.apple.com/us/app/genius-scan-pdf-scanner/id377672876?mt=8
Compass
https://play.google.com/store/apps/details?id=com.gn.android.compass
https://play.google.com/store/apps/details?id=software.gn.compass.pro
https://itunes.apple.com/us/app/compass/id520985073?mt=8
Bubble level
https://play.google.com/store/apps/details?id=net.androgames.level
https://itunes.apple.com/us/app/ihandy-level-free/id299852753?mt=8
Super-Bright LED Flashlight
https://play.google.com/store/apps/details?id=com.surpax.ledflashlight.panel
https://itunes.apple.com/us/app/flashlight-o/id381471023?mt=8
Sound Meter
https://play.google.com/store/apps/details?id=kr.sira.sound
https://itunes.apple.com/us/app/digital-sound-meter-free/id333185568?mt=8
Smart Measure
https://play.google.com/store/apps/details?id=kr.sira.measure
https://itunes.apple.com/us/app/easymeasure-measure-your-camera!/id349530105?mt=8
Metal Detector
https://play.google.com/store/apps/details?id=kr.sira.metal
https://itunes.apple.com/us/app/metal-detector-free/id333259405?mt=8
Universal TV Remote
https://play.google.com/store/apps/details?id=com.Sandpiper.SamyGoRemote
https://itunes.apple.com/us/app/dijit-remote-tv-guide-netflix/id391065642?mt=8
Swiss Army Knife
https://play.google.com/store/apps/details?id=com.digital_and_dreams.android.swiss_army_knife
Smart tools
https://play.google.com/store/apps/details?id=oasisllc.smart.tools
Advance ToolKit
https://play.google.com/store/apps/details?id=com.smart.toolkit.gadgets
Tools Box Smart Free 100%
https://play.google.com/store/apps/details?id=com.student.studio.app.smarttoolbox
My Distance Meter
https://play.google.com/store/apps/details?id=com.shield.my_distance_meter
Distance Meter
https://play.google.com/store/apps/details?id=omaeno.tools.kyorisokutei
My Sound Meter
https://play.google.com/store/apps/details?id=com.shield.my_sound_meter
My Travel Meter
https://play.google.com/store/apps/details?id=com.shield.mytravelmeter
Metal Detector
https://play.google.com/store/apps/details?id=kr.sira.metal
Unit Converter
https://play.google.com/store/apps/details?id=kr.sira.unit
Smart Mirror
https://play.google.com/store/apps/details?id=kr.sira.mirror
Smart Call Accept
https://play.google.com/store/apps/details?id=com.dungelin.smartcallaccept
Smart Unit Converter
https://play.google.com/store/apps/details?id=nav.scon
Smart Magnifier
https://play.google.com/store/apps/details?id=kr.sira.magnifier
Wifi Radar
https://play.google.com/store/apps/details?id=girsas.wifiradar
Real Speed Gun
https://play.google.com/store/apps/details?id=com.emil.myapp.speedgun
Night Vision Camera HD
https://play.google.com/store/apps/details?id=com.usefullapps.nightvisioncamera
https://play.google.com/store/apps/details?id=com.thegrizzlylabs.geniusscan.free
https://itunes.apple.com/us/app/genius-scan-pdf-scanner/id377672876?mt=8
Compass
https://play.google.com/store/apps/details?id=com.gn.android.compass
https://play.google.com/store/apps/details?id=software.gn.compass.pro
https://itunes.apple.com/us/app/compass/id520985073?mt=8
Bubble level
https://play.google.com/store/apps/details?id=net.androgames.level
https://itunes.apple.com/us/app/ihandy-level-free/id299852753?mt=8
Super-Bright LED Flashlight
https://play.google.com/store/apps/details?id=com.surpax.ledflashlight.panel
https://itunes.apple.com/us/app/flashlight-o/id381471023?mt=8
Sound Meter
https://play.google.com/store/apps/details?id=kr.sira.sound
https://itunes.apple.com/us/app/digital-sound-meter-free/id333185568?mt=8
Smart Measure
https://play.google.com/store/apps/details?id=kr.sira.measure
https://itunes.apple.com/us/app/easymeasure-measure-your-camera!/id349530105?mt=8
Metal Detector
https://play.google.com/store/apps/details?id=kr.sira.metal
https://itunes.apple.com/us/app/metal-detector-free/id333259405?mt=8
Universal TV Remote
https://play.google.com/store/apps/details?id=com.Sandpiper.SamyGoRemote
https://itunes.apple.com/us/app/dijit-remote-tv-guide-netflix/id391065642?mt=8
Swiss Army Knife
https://play.google.com/store/apps/details?id=com.digital_and_dreams.android.swiss_army_knife
Smart tools
https://play.google.com/store/apps/details?id=oasisllc.smart.tools
Advance ToolKit
https://play.google.com/store/apps/details?id=com.smart.toolkit.gadgets
Tools Box Smart Free 100%
https://play.google.com/store/apps/details?id=com.student.studio.app.smarttoolbox
My Distance Meter
https://play.google.com/store/apps/details?id=com.shield.my_distance_meter
Distance Meter
https://play.google.com/store/apps/details?id=omaeno.tools.kyorisokutei
My Sound Meter
https://play.google.com/store/apps/details?id=com.shield.my_sound_meter
My Travel Meter
https://play.google.com/store/apps/details?id=com.shield.mytravelmeter
Metal Detector
https://play.google.com/store/apps/details?id=kr.sira.metal
Unit Converter
https://play.google.com/store/apps/details?id=kr.sira.unit
Smart Mirror
https://play.google.com/store/apps/details?id=kr.sira.mirror
Smart Call Accept
https://play.google.com/store/apps/details?id=com.dungelin.smartcallaccept
Smart Unit Converter
https://play.google.com/store/apps/details?id=nav.scon
Smart Magnifier
https://play.google.com/store/apps/details?id=kr.sira.magnifier
Wifi Radar
https://play.google.com/store/apps/details?id=girsas.wifiradar
Real Speed Gun
https://play.google.com/store/apps/details?id=com.emil.myapp.speedgun
Night Vision Camera HD
https://play.google.com/store/apps/details?id=com.usefullapps.nightvisioncamera
Tuesday, May 20, 2014
Quixey: App Search & Discovery
https://www.quixey.com/search/android
https://play.google.com/store/apps/details?id=com.quixey.android
There are millions of apps and you need the best app search to find the right ones. Quixey allows you to search for apps by describing what you want to do. You no longer need to know an app’s name to get good results.
The clean interface makes app discovery fun and simple. Quixey’s app search has been featured in TechCrunch, VentureBeat, Mashable, Lifehacker, The Next Web, New York Times and The Wall Street Journal.
Product Highlights:
★ Search - App search that works. You don’t need to know an app’s name to get great results. Search for apps by describing what you want to do and we’ll find apps to help.
★ Trending - Check out the latest and greatest apps. No matter who you are - parent, student, teacher, traveler, athlete, gamer, musician - we have the top trending apps picked for you.
★ Browse - We have reinvented the look of categories. Take our browse wheel for a spin to find the perfect app for you (not available on Gingerbread OS).
★ Sample - Curious what types of apps are out there? Check out our sample queries to see what other people are searching for.
https://play.google.com/store/apps/details?id=com.quixey.android
There are millions of apps and you need the best app search to find the right ones. Quixey allows you to search for apps by describing what you want to do. You no longer need to know an app’s name to get good results.
The clean interface makes app discovery fun and simple. Quixey’s app search has been featured in TechCrunch, VentureBeat, Mashable, Lifehacker, The Next Web, New York Times and The Wall Street Journal.
Product Highlights:
★ Search - App search that works. You don’t need to know an app’s name to get great results. Search for apps by describing what you want to do and we’ll find apps to help.
★ Trending - Check out the latest and greatest apps. No matter who you are - parent, student, teacher, traveler, athlete, gamer, musician - we have the top trending apps picked for you.
★ Browse - We have reinvented the look of categories. Take our browse wheel for a spin to find the perfect app for you (not available on Gingerbread OS).
★ Sample - Curious what types of apps are out there? Check out our sample queries to see what other people are searching for.
RemoteBox - Manage VirtualBox on Servers
http://remotebox.knobgoblin.org.uk/
What is RemoteBox?
RemoteBox is a VirtualBox client. In essence, you can remotely administer (ie over the network) an installation of VirtualBox on a server, including its guests and interact with them as if they were running locally. VirtualBox is installed on 'the server' machine and RemoteBox runs on 'the client' machine. RemoteBox provides a complete GTK graphical interface with a look and feel very similar to that of VirtualBox's native GUI. If you're familiar with other virtualization software, such as VMWare ESX, then think of RemoteBox as the "poor man's" VI client.
Why is this useful?
VirtualBox is intended to be used as a desktop virtualization solution. That is, you install it on a machine and use VirtualBox locally. This means that the guests on the local machine will consume resources, taking them away from other tasks. Additionally, the guests will not be available to other machines or will be unavailable if the local machine is off. RemoteBox changes this by allowing you to run the guests on another machine (ie the server) but still interfact with them as if they were installed locally. This free's up resources on your local machine, allows you to interact with the same guests from multiple machines (eg a desktop and a laptop) and the guests can continue to run, even when the client machine is off. The guest's can also take advantage of the additonal CPU, memory and storage that a servers tend to have. As VirtualBox and RemoteBox are both cross-platform it allows you to use different operating systems for the client and server. For example, you may prefer to use VirtualBox on a Linux server but wish to interact with the guests from a Mac OS X client machine.
How does it work?
VirtualBox includes a special web service which exposes its API over the network using a protocol called SOAP. RemoteBox also speaks SOAP and communicates with VirtualBox to perform the various tasks such as creating or powering on guests, etc. When guests are 'powered on', they are started up in a mode called headless. This essentially means the guest's display is 'hidden' but is accessible using the Remote Desktop Protocol (RDP). RemoteBox uses an RDP client to show the display of a guest, locally on the client machine and is completely interactive.
What does RemoteBox run on?
The RemoteBox client is known to run on Linux, Solaris, Mac OS X and various modern flavours of BSD. VirtualBox offically runs on Linux, Solaris, Mac OS X and Windows as well as 'unofficially' on FreeBSD. The client and server machines do not need to be running the same operating system. For example, you may have VirtualBox installed on a Windows server but interfact with the guests from a FreeBSD client.
Feature Summary
|
Adding Static Routes On Various *NIX (Linux,AIX,HP-UX)
Static routes are generally required for traffic that must not, or should not, go through the default gateway. In this article we will discuss how to add static routes in variox nix.
Scenario : Suppose if you want that all the traffic to network 172.168.102.0/24 should use 172.168.101.1 as gateway. This can be done by adding a static route in the kernel routing table as shown below.
Adding Static Route in Linux from the Command line :
# route add -net 172.168.102.0 netmask 255.255.255.0 gw 172.168.101.1 dev eth0
OR
# ip route add 172.168.102.0/24 via 172.168.101.1 dev eth0
Above Commands will make changes to the routing table temporary and not permanent. Use any of below mention command To check Routing tables in Linux :
# route -n
# netstat -nr
# netstat -nr
Steps to make the static Route Persistent Across the reboot :
In case of RHEL5.X / CentOS 5.X
Create a file route file
# vi /etc/sysconfig/network-scripts/route-eth0
172.168.102.0/24 via 172.168.101.1 dev eth0
172.168.102.0/24 via 172.168.101.1 dev eth0
Save and close the file and Restart network service
# service network restart
In case of RHEL6.X / CentOS 6.X
# vi /etc/sysconfig/network-scripts/route-eth0
GATEWAY0= 172.168.101.1
NETMASK0=255.255.255.0
ADDRESS0= 172.168.102.0
GATEWAY0= 172.168.101.1
NETMASK0=255.255.255.0
ADDRESS0= 172.168.102.0
Save and close the file and Restart network service
# service network restart
Adding Static Routes in AIX :
Step:1 Go to the SMITTY menu for routes
Step:2 Select Type of route 'net' or 'host' ( if default route then leave set to 'net' )
Step:3 Enter the destination address.
Step:4 Enter the gateway address ( on the line that “* default GATEWAY Address")
Step:5 If a 'net' or default route , enter the 'Network Mask' , if host do not set 'Network Mask'
Step:6 Enter the network interface for this route. To select from the list arrow down to the 'Network Interface' line and hit [F4] or [ESC]+ [4] to display list of available interfaces.
Step:7 Hit [ENTER] TO APPLY . You should recieve a return status of “OK"
Step:8 To exit the smitty , type [F10] or [0]
Step:9 Verify that your routes have been configured
# netstat -nr | grep UG
Adding Static Route in HP-UX
Step:1 Make a backup copy of '/etc/rc.config.d/netconf'
Step:2 Add a stanza to /etc/rc.config.d/netconf for the new route . Make sure you use a new array number for the stanza
Example : Replace 'nn' with the next number in the list.
ROUTE_DESTINATION[nn]="IP-of-NewHost"
ROUTE_MASK[nn]=" “
ROUTE_GATEWAY[nn]="IP-of-Router"
ROUTE_COUNT[nn]=""
ROUTE_ARGS[nn]=""
ROUTE_MASK[nn]=" “
ROUTE_GATEWAY[nn]="IP-of-Router"
ROUTE_COUNT[nn]=""
ROUTE_ARGS[nn]=""
Save & Close the file
Step:3 Now run the below command to re-read the netconf file and add the route
# /sbin/init.d/net start
Note: Run the above command with start option only because it will add new route without effecting existing network configuration.
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.
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