Posts

How to Install, Delete, Update packages in RedHat/Fedora/CentOS

Introduction

RPM (Red Hat Package Manager) is an open source package management utility for RHEL, CentOS and Fedora based systems and is used for following purposes:

  • Install
  • Delete
  • Update
  • Query
  • List
  • Verify

Syntax

RPM filename contains four parts Package Name, Version, Release & Architecture Name

vsftpd-2.2.2-14.el6.i686.rpm

Package Name – vsftpd
Version – 2.2.2-14
Release – el6
Architecture – i686

1) Install an RPM Package

To install an RPM Package on linux machine use the following command.

# rpm -ivh vsftpd-2.2.2-14.el6.i686.rpm

Preparing... ########################################### [100%]
1:vsftpd ########################################### [100%]

where
-i : install
-v : verbose
-h: print hash marks

2) Delete an RPM Package

To remove a package use -e option in order to delete an RPM package.

# rpm -e vsftpd

3) Update an RPM Package

Use -U option to update/upgrade an RPM package.

# rpm -Uvh vsftpd-2.2.2-14.el6.i686.rpm
Preparing... ########################################### [100%]
1:vsftpd ########################################### [100%]

4) Query an RPM Package

To query specific package use -qa option

# rpm -qa|grep vsftpd
vsftpd-2.2.2-14.el6.i686

-q : Query a package

5) List an RPM Package

To view the package list use -ql option

# rpm -ql vsftpd-2.2.2-14.el6.i686.rpm

6) Verify an RPM Package

In order to verify RPM package use the following command

# rpm -Va

Note: There is another easiest method to install,delete,update packages in RedHat/Fedora/CentOS based machine through YUM commands.

How to Enable mysql slow query logs in Debian/Ubuntu

Step 1: Modify /etc/mysql/my.cnf File

To enable mysql slow query logs add the lines in my.cnf file.

#vi /etc/mysql/my.cnf

log_slow_queries = /var/log/mysql/mysql-slow.log
long_query_time = 2
log-queries-not-using-indexes

Step 2: Restart mysql service

After inserting the above entries restart mysql server.

#service mysqld restart