Postgresql is open source object-relational database system and it is also widely use likewise mysql database system. If you are familiar with mysql you must be aware that in single line you can pass the password of mysql user for eg. mysql -u root -p password. But in postgresql it is not like that. Solution:…
Few days back I did some changes in /etc/postfix/virtual file and restarted the postfix service.Today I saw some error in mail logs stating “hash:/etc/postfix/virtual is unavailable. open database /etc/postfix/virtual.db: No such file or directory” I checked /etc/postfix/virtual.db about its existence by using command ls -l /etc/postfix/virtual.db and found it was not there. To resolve this…
Zip is command in linux is used for compressing files and directory.In this post we will learn how to zip the directory or folder in linux. To compress directory use the below given format zip -r give-file-name.zip Directory-name example: root@tuxworld:/opt# ls -ld teamviewer8/ drwxr-xr-x 6 root root 4096 Oct 2 08:43 teamviewer8/ root@tuxworld:/opt# zip -r…
After installing the HAproxy 1.4 in CentOS 6.4 bydefault logging of haproxy was not enable.To enable the logging of HAProxy you have to enable it in rsyslog (In CentOS 6.4 minimal installation,rsyslog version 5.2 is shipped). To setup logging in HAproxy,follow the given below steps Step 1: In Global Section of haproxy.cfg put the value…
Today in this tutorial we will learn how to set maintenance page in PHP based website.In this example publicly the website will show maintenance page for all but the maintenance page will not be visible for your network. In other words,from your network you will see complete website (not maintenance page).The developer and system admin…
Whois is a protocol which runs on port no. 43 and it is also act as query. Whois helps to get the information regarding internet resources like domain name and IP Address network blocks. Mostly it is widely used for getting information about domain like owner of domain name,its registrar,Date of expiry etc. Install whois…
In this turorial we will learn,how to configure Varnish 3.x vcl file for WordPress.We will setup varnish cache server for wordpress site.This will increase the page load speed of the site/blog.Recently I migrated my server to DigitalOcean.To migrate the server from web hosting to cloud server was not done first time,it was also done in…
In this tutorial we will learn about,how to install and configure Varnish Cache server on CentOS/RHEL 6.x. We will install varnish 3.0 version in CentOS 6.x . I am writing this basic tutorial to setup your first varnish in server.Here we will use rpm packages for installation.The rpm packages are available as per your operating…
SCP stands for secure copy.It is based upon SSH (Secure Shell) protocol.SCP is used for securely transferring the files between local and remote system. Note: If SSH service is not running or deny by firewall or IPTABLES of system then SCP will also not work. Syntax: scp SOURCE-FILE-LOCATION TARGET-LOCATION (1) SCP file from local to…
How to run command in remote linux / unix system by using ssh If you are working as a linux system admin, it is important to know how you can execute the command in remote linux or unix based operating system by using ssh.The method is very useful and you can also use it in…
While setting the new Git server with gitweb I saw this issue.Generally never seen before,here Gitweb page was not displaying correctly. You can see the below given screenshot: While debugging the issue,it is found that the problem was with MIME for css and javascript. To solve this issue ,I only approached to create a .htaccess…
To know about how many lines exist in file is important for System Admin.There are sometimes very huge files which has lot of line numbers hence it is not advisable to open the file using cat command or any file editor like vi,vim,nano etc., because it takes lot of time to open it. Hence it…
In this post we will learn how to install Wildfly which was earlier known as JBOSS Application Server. For Wildfly the main dependency is Java. In your system Java must be installed and Java environment variable should also be set. I have done this practical after doing minimal installation of CentOS 6.4 which is 64…
When I started learning linux ,for listing files and directory I firsts learnt the command ls. ls command is widely in linux and Unix like operating system.It is a system command which by default shipped with operating system.Today I am sharing the 4 commands by which you can list file and directories.On other hand you…
This is a simple mysql backup script.The script can be used manually as well as in crontab. Edit the below given script and provide the information required in the script. The script will take the backup in .sql format later it will compress the .sql file and in end send the mail about the status…