Log files are very important and valuable tool available in Linux system security. Logrotate is a log file manager program which provides the administrator with an up-to-date record of events taking place on the system. It may also be used to backup log files. It regularly rotates log files by removing old one from the system and creating new log files as the log files grow too large. This rotation is based on the age of the file, file size and can also set cron utility. It can also be used to compress log files and to configure emails to user when they are rotated. The point of log file rotation is to prevent log files from growing indefinitely.
Run-level is a preset operating state on a Unix-like operating system. A run-level is a software configuration of the system that allows only a selected group of processes to exist. A system can be booted into (i.e., started up into) any of several run-levels, each of which is represented by a single digit integer. Each run-level designates a different system configuration and allows access to a different combination of processes (i.e., instances of executing programs).
Denial-of-service attack (DoS attack) or Distributed Denial-of-service attack (DDoS attack) is an attempt to make a machine or network resource unavailable to its intended users. This attack generally target sites or services hosted on high-profile web servers such as banks, credit card payment gateways, and even root nameservers. DoS attacks are implemented by either forcing the targeted computer to reset, or consuming its resources so that it can no longer provide its services or obstructs the communication media between the users and the victim so that they can no longer communicate adequately.
As long as you manage a website, the term server migration would bang you at least once. Well, this arises due to a number of factors such as moving to a powerful server in order to have better resources to process data, change in environment like updating to a newer version of your program or web server for better results or change of service provider. The term server migration may hit you in a great deal, because you fear about lose of data, unstable websites or down-times. This article focuses on how to achieve webserver migration with zero down time without any data loss. Lets start!