Today, I learned about bottom – yet another command line process/system monitoring tool. I’m probably late to this one, however, I want to quickly share this tool with readers. Have you ever found yourself needing a detailed and real-time overview of system resource usage on your server or computer? Specifically for Linux, there are various […]
What is iowait and how does it affect Linux performance?
iowait (wait, wa, %iowait, wait%, or I/O wait) is often displayed by command-line Linux system monitoring tools such as top, sar, atop, and others. On its own, it’s one of many performance stats that provide us insight into Linux system performance. I/O wait came up in a recent discussion with a new client. During our support […]
Linux server needs a RAM upgrade? Check with top, free, vmstat, sar
Sometimes, it can be a bit of a challenge knowing if and when you should upgrade the RAM (random access memory) on your Linux server. Even more so, when deciding how much memory you should add, or if you have adequate memory, how do you make the best use of it? This article will walk […]
Are you measuring Linux web server memory usage correctly?
This article was first published in 2014. After which, there was a welcomed change to the Linux kernel in 2016, as mentioned in the 2017 article: Does your Linux server need a RAM upgrade? Let’s check with free, top, vmstat and sar. As a server administrator or web developer, it’s your responsibility to stay informed about […]
Linux Performance: Almost Always Add Swap Space – Part 2: ZRAM
In the previous article, we looked at how swap space, particularly swapping, can severely slow down Linux performance. We then tweaked Linux kernel parameters to better use server memory and 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 […]
Linux Performance: Almost Always Add Swap Space
We know that using Linux swap space instead of RAM (memory) can severely slow down performance. So, one might ask, since I have more than enough memory available, wouldn’t it be better to delete swap space? The answer is: No. There are performance benefits when swap space is enabled, even when you have more than […]
Raspberry Pi Performance: Add ZRAM and these Kernel Parameters
Previously, I published a Pinebook Pro review article on this blog. Similar to the Pinebook Pro, the Raspberry Pi and, more recently, the Raspberry Pi 4 are also ARM-based. With good results, I’ve applied some of the optimizations mentioned in that previous article to the Raspberry Pi 4. I wanted to share these tweaks and […]
btop – the htop alternative
Have you ever experienced slow application performance on a server and wondered which process was causing the bottleneck? In a production server environment, monitoring system performance and hardware resource usage in real-time is crucial. That’s where system monitoring tools come in handy. And, with the availability of numerous command-line system monitoring tools, you’re spoiled for […]
PHP memory_limit – understanding and increasing
PHP’s memory_limit is per-script, just as a highway’s speed limit is per-vehicle. For example, although PHP’s memory limit may be set to 1GB, that does not mean that scripts will pile up to use that 1 GB. Let’s take a closer look at understanding PHP’s memory_limit setting. PHP memory_limit is a per-script setting PHP.net’s […]
“MySQL server has gone away” error – Solution(s)
The MySQL server has gone away error, which means that the MySQL server (mysqld) timed out and closed the connection. By default, MySQL will close connections after eight hours (28800 seconds) if nothing happens. However, in some cases, your web host, DBA, or app developer may have decreased this timeout setting, as discussed below. MySQL […]