Linux Performance: Almost Always Add Swap. Part 2: ZRAM

Previously, we looked at how swap space, particularly swapping, can severely slow down Linux performance. We then tweaked Linux kernel parameters to make better use of server memory and to avoid heavy swapping. That article created some debate and good arguments for and against swap space. For example, if you have more than enough memory […]

How to Kill Inactive SSH Sessions

So, you’ve been disconnected from your server a couple of times, resulting in inactive ssh sessions. You know this because when you use the “w” command, you see something like the following… 22:47:28 up 315 days, 21:09, 2 users, load average: 9.04, 8.17, 7.30 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root pts/0 ipxxx-xxx-xxx-xxx 23:54 26:40 […]

Linux benchmark scripts and tools

This list of Linux benchmark scripts and tools should prove helpful for quick performance checks of CPU, storage, memory, and network on Linux servers and VPS. Check each script before running from the command line. Most of these scripts will benchmark the CPU, memory, storage, and network. In most cases, the CPU Model, frequency, number […]

Your Web Host Doesn’t Want You To Read This: Benchmark Your VPS

Sept 27th, 2021: Added link to a great list of command-line benckmark scripts. June 17th, 2019: Added instructions for network speed test using speedtest-cli script. Nov 2nd, 2016: Included quick dd commands to check cached vs. uncached read performance. This article will highlight using the ‘dd’ Unix command for a quick benchmark of your Linux […]

atop – For Linux server performance analysis

We’re all familiar with top, a real-time system monitor. Some prefer htop and previously, I mentioned iotop for use with storage read/write monitoring. Let’s looks at another popular tool for Linux server performance analysis: atop.   Advantages of atop Atop is an ASCII full-screen performance monitor which can log and report the activity of all server processes. […]

htop: Quick Guide & Customization

htop is an interactive system monitor, but also a process-viewer, process-manager, strace tool and more. Sysadmins may opt to use htop when Unix top does not provide enough information about system processes. htop uses a cursor-controlled interface for sending signals to processes. One example where this comes in handy is: you don’t have to type […]

Free vs. Available Memory in Linux

At times we will need to know precisely how our Linux systems use memory. This article will examine how to use the free command-line utility to view memory usage on a Linux system. In doing so, we will clearly define the difference between free vs. available memory on Linux systems.   Free vs. Available memory […]

90 Linux Commands frequently used by Linux Sysadmins

There are well over 100 Unix commands shared by the Linux kernel and other Unix-like operating systems. If you are interested in the commands frequently used by Linux sysadmins and power users, you’ve come to the place. Recently, I published a five-part series covering commands often used by Linux sysadmins. Below I’ve listed the 90 […]

Linux Commands frequently used by Linux Sysadmins – Part 5

This is the final part of the five-part series entitled: Linux Commands frequently used by Linux Sysadmins. So far, we’ve covered over 50  commands regularly used by Linux sysadmins and power users. Refer to part 1, part 2, part 3, and part 4. This article will look into another set of commands and command-line tools […]

Linux Commands frequently used by Linux Sysadmins – Part 4

We are now up to part 4 of this five-part series entitled: Linux Commands frequently used by Linux Sysadmins. By the end of this series, we will cover at least 50 commands. Thus far, we touched on around 60 commands often used by Linux Sysadmins and power users. Refer also to part 1, part 2, […]