Interview Questions on Linux Servers
1. How can you create a password less connection between multiple Linux machine?How to create a password less authentication for ssh in Linux?2. What are the types of authentication which can be used...
View ArticleWhat is Virtual memory, paging and swap space ?
Virtual memory is a memory management technique that is implemented using both hardware and software which gives an application program the impression that it has contiguous working memory (an address...
View ArticleHow to auto start service after reboot in Red Hat Linux?
You can run the below command to auto start the service after reboot# chkconfig service_name onBut the above command will enable the service only for the current run level so I always prefer using the...
View ArticleHow to check all the currently running services in Linux
To find the status of any single service# service vsftpd statusvsftpd (pid 5909) is running...To get the status of all the running services# service --status-all | grep runningacpid (pid 5310) is...
View ArticleWhat are the s and k scripts in the etc rcx.d directories?
To understand this you need to have a brief knowledge on the booting procedure of Linux machine.Running all the scripts under /etc/rc.d is the last step of successful booting a Linux OS.As per the 5th...
View ArticleHow to log iptables messages in a different log file
Generally all the info to error level messages are logged inside /var/log/messages but it makes hard to differentiate between long list of logs inside messages.To separate the iptables related logs in...
View ArticleWhat is swappiness and how do we change its value?
It is a feature in Linux which controls the degree to which the kernel prefers to swap in the procedure of freeing memory. It can be set to values on a scale from 0 to 100. A low value means the kernel...
View ArticleWhat is the difference between "su" and "su -" ?
If we check the man page for susu - run a shell with substitute user and group IDswhich means that if you use# su -you are switching user to the root user and asking the system to change all the...
View ArticleUnderstanding Kernel-PAE in Linux
The Physical Address Extension (PAE) is a feature implemented in modern x86 processors. PAE extends memory addressing capabilities, allowing more than 4 GB of random access memory (RAM) to be...
View ArticleWhy is Linux more secure than windows and any other OS?
Now we hear many times from most of the people around us claiming that Linux is much more secure than Windows or Linux is very secure.But what are the things in Linux that makes it secure than Windows...
View Article15 tips to enhance security of your Linux Server
It is not possible for me to tell you with all the possible features because that is out of my knoweldge level but I will try to put everything I know which can be used to make sure that your Linux...
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Red Hat Enterprise Linux 5.5 Installation Guide (Screenshots)
Before you start installing Red hat Linux, You should know the pre-requisites for the same i.e. the system requirementsSystem Requirement for Red Hat Linux 5ParametersRequirementsCPU TypePentium 4 or...
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How to register Red Hat Linux with RHN ( Red Hat Network )
I will show you simple steps to register your Red Hat Linux server with Red Hat Network (RHN).NOTE: This is only possible if you have a valid subscription from Red Hat LinuxLogin to your RHEL server...
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How to secure Apache web server in Linux using password (.htaccess)
Here I have provided simple steps to configure your webpage with login authentication. So that you can prevent unauthorized access to your pages on the website.I have used Red Hat 6 machine for these...
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RHEL: Kernel will not boot, system freeze at 'starting udev'
Error:Linux machine does not boots and gets stucked at udev promptExplanationThis is a known bug in Red Hat. Please follow the belw link to reach out the bug detailsBug 645940 - Kernel will not boot,...
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How to configure Samba 4 as Secondary Domain Controller
I started reading Samba4 Join a DC article with a belief that it shows the steps required to configure a backup domain controller for our PDC in Samba 4. (Please correct me if I am wrong).But when I...
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Tutorial for Monitoring Tools SAR and KSAR with examples in Linux
sar is a short term abbreviation for System Activity Report.Important points for sarIt can be used for realtime monitoring of Linux system performance.The sar command writes to standard output based...
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Configure Red Hat Cluster using VMware, Quorum Disk, GFS2, Openfiler
In this article I will be showing you step by step guide to install and configure Red Hat Cluster using VMware Workstation 10.These are the things which I would be using as per my lab setup:VMware...
View ArticleScript to take backup of any critical directory in Unix/Linux
This is a script which can be used to backup of your home directory on a day basis where a compressed backup of your home directory /home will be saved inside /backup directory.You can put this script...
View ArticleFix "error while loading shared libraries *:No such file or directory"
It happens many time when you are trying to execute some command an error pops out likethe one shown belowerror while loading shared libraries: libacl.so: cannot open shared object file: No such file...
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