How to version control /etc directory in Linux

In Linux, /etc directory contains important system-related or application-specific configuration files. Especially in a server environment, it is wise to back up various server configurations in /etc directory regularly, to save trouble from any accidental changes in the directory, or to help with re-installation of necessary packages. Better yet, it is a good idea to […]
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How to check what services are enabled on boot in Linux

There are so-called startup services in Linux which are set to launch automatically when a Linux system boots up. Such startup services include basic system configurations (e.g., networking, security modules, hardware peripherals), as well as various add-on services (e.g., NFS, MySQL, VPN, rsync), which all are needed for a particular Linux system to operate as […]
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How to checkpoint and restore a Linux process

Suppose you have a Linux process running, and want to capture its current snapshot after freezing it. The frozen process is then loaded from the snapshot to resume. Such concept of process checkpointing can be very useful under a variety of circumstances. It can be used for process backup, live migration, faster boot-up service, etc. […]
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How to monitor disk I/O in Linux from command line

If your Linux system gets slow down due to heavy disk I/O activities, you probably want to know which processes or users (in case of multi-user systems) are the culprit for such activities. You may also wish to monitor disk I/O trending over time as part of daily Linux system administration. Here I will introduce […]
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How to monitor memory usage of a Linux process

When you check memory usage of individual Linux processes, you may often use top command line utility. While top command is a solid program for system monitoring purposes, there are other enhanced versions of top, in terms of user-friendliness. One such tool is called htop. The htop utility is an interactive process viewer for Linux. […]
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How to kill multiple processes at once with grep

There are cases where you want to kill multiple processes that match a certain pattern in their command line strings. For example, suppose you want to kill all processes that are running commands with keyword “jppf” in their arguments. $ ps aux | grep jppf xmodulo 3324 0.1 2.9 156524 15176 pts/0 Sl 22:16 0:01 […]
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