How to Scheduled ‘Task’ with Cron Jobs in Linux

crontab-format CRONTAB

A crontab file is a simple text file containing a list of commands meant to be run at specified times. It is edited using the crontab command. The commands in the crontab file (and their run times) are checked by the cron daemon, which executes them in the system background.

Each user (including root) has a crontab file. The cron daemon checks a user’s crontab file regardless of whether the user is actually logged into the system or not.

Here is an explanation of the crontab format.

  1. Minute when the process will be started                            [0-60]
  2.  Hour when the process will be started                               [0-23]
  3.  Day of the month when the process will be started      [1-28/29/30/31]
  4.  Month of the year when the process will be started      [1-12]
  5.  Weekday when the process will be started                       [0-6] [0 is Sunday]

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Amazon S3 cloud storage access from command line in Linux

s3cmdHow to access Amazon S3 BY command line

Amazon S3 is stand for Simple storage service that is storage for the Internet. It as a, “simple storage service that offers software developers a highly-scalable, reliable, and low-latency data storage infrastructure at very low costs”.

Amazon S3 provides a simple web service interface which you can use to store and retrieve any amount of data, at any time, from anywhere on the web. Using this web service, developers can easily build applications that make use of Internet storage.

Here below i will describe how to access Amazon S3 cloud storage from the command line in Linux Step by step you can learn and execute.

One of the most popular Amazon S3 command line clients is s3cmd, which is written in python. As a simple AWS S3 command line tool, s3cmd is ideal to use when you want to run scripted cron jobs such as daily backups. Continue reading

Important AWS DevOps Interview Questions To Ask

AWS_DevopsTOP AWS DevOps’s Questions

If you’re cloud engineer, specially someone who knows Amazon Web Services (AWS) you’ll want to have a bunch of questions to ask them to share their knowledge.  As with any AWS DevOps interview.

what is VPC ?

virtual private cloud (VPC) is a virtual network dedicated to your AWS account. You can configure or create your VPC as per requirement like select region, create subnets (IP- CIDR), configure route tables, security groups, Internet gateway etc to your AWS account By which you can launch your AWS resources, such as Amazon EC2, RDS instances etc, into your VPC Continue reading

Linux Basic Commands for Beginners

basic_linux_commandLinux Basic Commands and Examples of them

Commands: A instruction  for a computer or device to perform a specific task know as ‘Command’. It give through terminal as input (by user), so also we can say that command is an interpreter.

[gaurav@gauravx ~]$____

Command line:  A command line is a text-based interface which can be use to input instruction to a computer system. A Linux command line is provided by a program called “The Shell“.  So in previous post shell are covered, where or as all know there are many Shells have been developed.  So The default shell for users in Linux is the BASH Shell (Borne Again shell) and also it is in MAC OSx.

Instruction: Open terminal ( ctrl+shift t ) it displays a string like “ [user@hostname~]$ _ or  [root@hostname~]$#_” mean of this, it is waiting for a command from the user  ‘it is called Shell prompt’.

So command entered at the shell prompt have three basic parts Continue reading

System Administration

system_adminSystem Administration

System Administration, The Administration is designed for the IT Professional. There are various category of Administration like,

  • Network Administrator
  • Project Administrator
  • IT Administrator
  • Linux System Administrator
  • Data Base Administrator etc

The person who is responsible for setting up and maintaining the system or server is called as the system administrator. System administrators may be members of an information technology department.

System administration is the field of work in which someone manages one or more systems, software, hardware, servers or workstations.A system administrator, or sysadmin, is a person responsible to maintain and operate a computer system or network for a company or other organization. System administrators are often members of an information technology department.  Its goal is ensuring the systems are running efficiently and effectively. Continue reading