Tar Files extraction Unix / Linux

Q: How can I extract  specific file from a tar ball ? Tar or Tar ball is a single file  bundled with files &/ directories. First  we will discuss about general extraction of a files from tar ball. Unpack or extract a tar file : To unpack or extract a tar file, type: tar -xvf myfile.tar some times to save more space and bandwidth...

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MobaXterm free Xserver and SSH client

Recently when I am browsing internet  for Unix connectivity tools I came across a wonderful tool called MobaXterm. As per the MobaXterm team  its "an enhanced terminal for Windows with an X11 server, a tabbed SSH client and several other network tools for...

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Manually Installing PHP in Linux

Before installing php,  we need to install apache.The most recent version of Apache HTTP Server may be obtained from >> Apache Download. 1) Download  & Unpack Apache HTTP server Package: Download and unpack Apache http server package  from the location listed above, and unpack it. Download Link: Apache Download gzip -d httpd-2_x_NN.tar.gz tar...

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WEBMIN- Managing Unix Systems Graphically

What is Webmin? Webmin is a web-based interface for system administration for Unix. Using any modern web browser, you can setup user accounts, Apache, DNS, file sharing and much more. Demo: http://webmin-demo.virtualmin.com/   login: demo &  password: demo. Download Link: http://www.webmin.com/download.html  How to Install: Install...

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Run VIO commands from the HMC using "viosvrcmd" without VIOs Passwords

Recently  we got a situation where  in we don't know the passwords of  either padmin/root of VIOS  but need to run commands in VIOs. Found an interesting command  in HMC  called "viosvrcmd",which will enble us to run commands on VIOs through HMC. viosvrcmd -m managed-system {-p partition-name | --id partition-ID} -c...

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Expressions used with if condition in shell scripts

1-1. Primary Expressions PrimaryMeaning [ -a FILE ]True if FILE exists. [ -b FILE ]True if FILE exists and is a block-special file. [ -c FILE ]True if FILE exists and is a character-special file. [ -d FILE ]True if FILE exists and is a directory. [ -e FILE ]True if FILE exists. [ -f FILE ]True if FILE exists and is a regular file. [ -g FILE ]True...

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How to change system hostname in Linux ?

Recently  we got a request from one of our  visitor to post article related to hostname change in Linux operating systems. I am going to cover this  now. There are two general way to do this  1)  Temporary  2)  Permanent First we go and learn about how to check host name (system name) of the server. Use "hostname"...

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Getting "Server refused to allocate pty" upon login attempt

Problem(Abstract) You are unable to log into AIX because the maximum number of pseudo-terminals have already been allocated. Symptom An attempt to log into AIX via telnet or ssh results in this error: "Server refused to allocate pty" - You have increased the maximum number of ptys but you still see the problem. - Each time you log in, the pty...

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PowerHA/HACMP Moving Resource Group (RG) one node to other

We are going to discuss about the resource group (RG) movement one node to other in PowerHA. Here are the steps 1) Extending PATH vairable with cluster paths Sometimes cluster paths are not included in default path ,run below command incase if you are not able to run commands directly. export PATH=$PATH:/usr/es/sbin/cluster:/usr/es/sbin/cluster/utilities:/usr/es/sbin/cluster/sbin:/usr/es/sbin/cluster/cspoc 2)...

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Editing the /etc/inittab File in Maintenance Mode

Problem(Abstract) This technote describes a technique for creating a minimal /etc/inittab file if no other tools are available. Symptom System hangs or crashes at boot time. Cause A bad entry in the /etc/inittab is keeping the system from booting properly. Resolving the problem Ordinarily if there is a problem with one or more entries in...

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How to enable the Name Service cache Daemon (NSCD)

Question How do you enable NSCD to improve the performance of the hostname, password, name and group lookup which is frequently being done by IBM Rational ClearCase? Cause By enabling the Name Service cache Daemon (NSCD) of the operating system, a significant performance improvement can be achieved when using naming services like DNS, NIS, NIS+,...

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Howto fix delay in SSH Login

Have you ever faced  login delays  when you tried to connect to the Linux systems, if yes this is happening due to  reverse DNS look-up  query that is been made to DNS Server. We can fix this issue as mentioned below steps: 1) Take /etc/ssh/sshd_config  backup # cp -p /etc/ssh/sshd_config /etc/ssh/sshd_config.`date '+%m-%d-%Y_%H:%M:%S'`...

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Install SNMP Service on RHEL or CentOS

Install SNMP Service on RHEL or CentOS In this article  we are going to learn  how to install and start  SNMP service in RHEL/CentOS. We need  to have  net-snmp rpm package installed on the servers , generally it would come with repository. 1....

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AIX RC Scripts

We need some applications  should be stopped and started gracefully without manual intervention during the reboots . Order to serve this purpose , we use  rc scripts in all unix flavors including AIX  . So, how do rc.scripts work: Write a single script,...

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How to Convert OpenSSH to SSH2 and vise versa

The program SSH (Secure Shell) provides an encrypted channel for logging into another computer over a network, executing commands on a remote computer, and moving files from one computer to another. SSH provides strong host-to-host and user authentication as well as secure...

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How to Remove a Virtual SCSI Disk

This document describes the procedure to remove a virtual disk in a volume group on a Virtual I/O Client, to map the virtual scsi disk to its corresponding backing device, and to remove the backing device from the Virtual I/O Server.  Please, read the entire document...

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AIX NFS Error - RPC: 1832-010 Authentication error fixing

AIX NFS Error and Solution - RPC: 1832-010 Authentication error [root-umserv1][/]> mount umserv2:/repos /mymnt mount: 1831-008 giving up on: umserv2:/repos vmount: The file access permissions do not allow the specified action. NFS fsinfo failed for server umserv2: error...

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Simple Script to Document LVM info in AIX

Friends here is a small script which can pull AIX OS LVM information of the server and if want it in a file re-direct the  output of the script into a file.This is best useful when your are doing system reboots and upgrades. Script: #!/bin/ksh # # Simple script to...

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