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 better to delete swap space? The short answer is, No. There are performance benefits when swap space is enabled, even when you have more than […]
25 Best CDN Providers 2021
A content delivery network also referred to as a content distribution network (CDN), is a geographically distributed network of data centers containing proxy servers. CDN providers serve internet content, including web objects (text, graphics, and scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), live streaming media, to name closer to and thus faster, to end-users. Some of […]
uptime command in Linux
This uptime command guide is a follow-up to my previous 90 Linux Commands frequently used by Linux Sysadmins article. As time allows, I will continue to publish articles on these 90 commands geared toward Linux sysadmins and power users. Let’s continue this series with the uptime command. The uptime outputs the current time, system uptime, number of logged-in […]
btop – the htop alternative
Meet btop, an aesthetically pleasing system resource monitor showing usage and stats for processor, memory, disks, network, and processes. btop is the lighter and faster C++ version and continuation of bashtop and bpytop. Over the years, the available options for command-line system monitoring tools have grown quite a bit. There is top, htop, glances, nmon, ytop, gtop, vtop, and […]
MySQL Database Performance: Avoid this common mistake
One frequent topic of support request emails I receive is MySQL database performance. Clients complain about MySQL using too much server memory, too many MySQL slow queries, the famous Mysql server has gone away error and many other MySQL performance-related issues. As such, I wanted to share the solution to a common MySQL configuration mistake. […]
Could not increase number of max_open_files to more than… (Solution)
A quick solution to the warning “Could not increase number of max_open_files to more than” when starting MySQL or MariaDB. For some background, read How MySQL Opens and Closes Tables. Here’s an excerpt: “The table_open_cache and max_connections system variables affect the maximum number of files the server keeps open. If you increase one or both of […]
50 Top ‘Internet of Things’ Security Solutions
A couple of months back, I decided to maintain a list of companies that offer IoT (internet of things) security tools and solutions which you can find below. Feel free to share your solutions, feedback, and tips for securing IoT devices. Going forward, I will update this list continuously. A few key questions arose after […]
78% of the web powered by PHP, 1% on PHP 8
Today, PHP is used by almost 80% of all the websites whose server-side programming language we know. Popular websites such as Slack, Etsy, Wikipedia, WordPress, Mailchimp, Canva, Indeed, Investing.com, and others are powered by PHP. However, in the coming months, many websites that fail to upgrade to the latest version of PHP 8 will be […]
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 […]