TOP command in Linux

Top-Command

top provides an ongoing look at processor activity in real time. It displays a listing of the most CPU-intensive tasks on the system, and can provide an interactive interface for manipulating processes. It can sort the tasks by CPU usage, memory usage and runtime. can be better configured than the standard top from the procps suite. … Read more

How to I disable echo cancellation module without removing the hardware?

You’ll need to: Stop Asterisk Stop DAHDI Unload the driver for your card from the Linux kernel Load the driver for your card with the module parameter “vpmsupport=0”. You can stop Asterisk with the command: asterisk -rx “core stop gracefully” You can stop DAHDI with the command: /etc/init.d/dahdi stop In order to find the kernel … Read more

find the number of CPU cores on Linux

Multi-core CPU processors are common nowadays, including dual-core processors (e.g., Intel Core Duo), quad-core processors (e.g., Intel Core i5), and hexa-core processors (e.g., AMD Phenom II X6). Also, many server-grade physical machines are equipped with more than one CPU processor. To find the number of physical CPUs: $ cat /proc/cpuinfo | grep “^physical id” | … Read more

MYSQL Partitioning : What is and HOW To ?

MySQL Cluster

The idea behind partitioning isn’t to use multiple servers but to use multiple tables instead of one table. You can divide a table into many tables so that you can have old data in one sub table and new data in another table. Then the database can optimize queries where you ask for new data … Read more

What is the best way to reduce the size of ibdata in mysql?

MySQL Cluster

The busiest file in the InnoDB infrastructure is /var/lib/mysql/ibdata1 This file normally houses many classes of information (when innodb_file_per_table is 0) Table Data Table Indexes MVCC (Multiversioning Concurrency Control) Data Rollbacks Segments Undo Tablespace Table Metadata Many people create multiple ibdata files hoping for better diskspace management and performance. It does not help. Unfortunately, OPTIMIZE TABLE against … Read more

Set Up MySQL Master-Master Replication

MySQL Cluster

Here we will help you to set up Master-Master replication between MySQL servers. In this setup if any changes made on either server will update on an other one. Setup Details: Master-1: 10.0.10.12 Master-2: 10.0.10.18 Database: empmaster Step 1. Set Up MySQL Master-1 Server Edit MySQL configuration file and add the following lines under [mysqld] section. Restart … Read more

remove duplicate mysql table

ALTER IGNORE TABLE `cdr` ADD UNIQUE(`uniqueid`)      

How to convert all tables from MyISAM into InnoDB?

If you omit the ENGINE option, the default storage engine is used. Normally, this is MyISAM, but you can change it by using the –default-storage-engine server startup option, or by setting the default-storage-engine option in the my.cnf configuration file. You may also want to change the default storage engine just for the current session. You can do this by setting the storage_engine variable: SET storage_engine=INNODB; … Read more