Forcing HTTPS on your website protects visitor data and improves SEO. The most common method is using .htaccess with Apache’s mod_rewrite module to redirect all HTTP requests to HTTPS. Basic HTTPS redirect Add this to your .htaccess file in the document root: RewriteEngine On RewriteCond %{HTTPS} !=on RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301] This performs a permanent…
On a Linux system, you often need to let regular users mount and unmount specific devices without requiring sudo or the root password. This is common for external drives, USB devices, or secondary internal disks. There are several approaches, each with different security and usability tradeoffs. Using /etc/fstab with the user Option The simplest approach…
Logging connections that hit rate-limit rules helps you identify brute force attempts and troubleshoot legitimate clients that are being blocked. The standard approach is to create a dedicated chain that logs packets before dropping them. Create a logging and drop chain First, create a custom chain to handle logging and dropping: iptables -N LOGNDROP iptables…
When you SSH to a server and see the warning below, your SSH client has detected that the server’s host key doesn’t match what’s stored locally: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)!…
HDFS snapshots provide a way to create read-only point-in-time copies of the filesystem or specific directories without duplicating data. Understanding their design helps you implement efficient backup strategies and recover from accidental deletions in production clusters. How HDFS Snapshots Work Snapshots in HDFS use copy-on-write semantics to avoid duplicating data. When you create a snapshot,…
Bind mounts let you mount a directory or file at another location in your filesystem hierarchy without duplicating the underlying data. They’re useful for directory reorganization, containerization, and working around path constraints. Here’s how to configure them in /etc/fstab. Basic Syntax The /etc/fstab syntax for bind mounts is straightforward: /source/path /mount/point none bind 0 0…
When you hit the open files limit on Linux, you’ll see errors like “Too many open files” — typically when running applications that create many temporary file handles. The default limit is often 1024, which isn’t enough for resource-heavy workloads. Check your current limit: ulimit -n Understanding soft and hard limits Linux maintains two types…
When you need to see what versions of a package are available in your Ubuntu repositories, there are several approaches depending on how much detail you need. Using apt-cache showpkg The most direct method is apt-cache showpkg, which lists all available versions along with their repository sources: apt-cache showpkg thunderbird This output shows version numbers,…
If you’re syncing emails with tools like offlineimap, you might notice a problem: when an email is deleted from the server, it’s also deleted locally. That’s by design—offlineimap performs synchronization, not backup. For actual backups, you need a tool that retrieves emails without deleting the originals. This post covers the best approaches in 2026. getmail:…
When you start a QEMU guest without explicitly configuring VNC, the display server may not bind to an address your VNC client can reach. You’ll see an error like: vncviewer: ConnectToTcpAddr: connect: Connection refused Unable to connect to VNC server This happens because QEMU defaults to SDL display output and doesn’t automatically expose VNC to…
Adobe Reader (acroread) is rarely the best choice for Linux users anymore. It’s unmaintained, doesn’t receive security updates, and performs poorly compared to modern alternatives. This guide covers better options and how to set up a functional PDF viewer on Linux Mint. Why Not Adobe Reader? Adobe stopped supporting Reader for Linux in 2013. The…
If you want to force HTTPS on your site, add this to your .htaccess file: RewriteEngine On RewriteCond %{HTTPS} off RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301] The key parts: RewriteCond %{HTTPS} off — matches only HTTP requests ^(.*)$ — matches any request https://%{HTTP_HOST}%{REQUEST_URI} — rebuilds the URL with HTTPS [L,R=301] — uses a permanent redirect (301) and…
Google Code was shut down in 2016, but you might still need to migrate legacy projects that were hosted there. If you have a local Git repository from Google Code or an archived mirror, here’s how to push it to GitHub while preserving all history. Prerequisites A GitHub account and a new empty repository created…
iOS 7.1.2 was released in 2014, and jailbreaking it today is neither practical nor recommended for active use. Why jailbreaking iOS 7.1.2 doesn’t make sense in 2026 Security vulnerabilities: iOS 7.1.2 reached end-of-life over a decade ago. It contains hundreds of unpatched security flaws that expose your device to malware, data theft, and network attacks….
The x86-64 ISA provides ucomiss and ucomisd for comparing SSE floating-point values. These instructions compute S1 – S2 and set the EFLAGS register (ZF, PF, CF) based on the result. Instruction Operands Purpose ucomiss S2, S1 Compare single-precision (32-bit) floats ucomisd S2, S1 Compare double-precision (64-bit) floats In AT&T syntax, the source operand is listed…
When you need to completely wipe a USB drive on Windows, you have several reliable options. Choose based on your security requirements: Disk Management for quick reformatting, DiskPart for automation, or secure erasure tools if the drive contained sensitive data. Using Windows Disk Management The simplest built-in approach: Connect the USB drive Open Disk Management…
systutorials.com runs on WordPress with the Twenty Fourteen theme (now legacy) and a custom Q2A installation for the Q&A section. If you’re rebuilding something similar, the approach differs between the two platforms. WordPress Theme Strategy If starting fresh today, Twenty Fourteen is outdated. Modern alternatives include: Twenty Twenty-Five — the current WordPress default, lightweight and…
If you’ve compiled a kernel module for a specific kernel version or need to pin a package to prevent automatic updates, you’ll want to exclude it from yum or dnf. There are several approaches depending on whether you need a permanent exclusion, per-repository exclusion, or temporary lockdown. Global Exclusions in Configuration The simplest approach is…
WordPress sanitizes HTML in comments by default for security. The <pre> tag is stripped unless you explicitly whitelist it. Here’s how to enable it without compromising security. Using wp_allowed_post_html Filter The proper approach is to whitelist <pre> and related tags via the wp_allowed_post_html filter: function allow_pre_in_comments( $allowed ) { $allowed[‘pre’] = array(); $allowed[‘code’] = array(…
SSH is fast enough for most tasks, but when you’re transferring large files, running multiple commands, or managing hundreds of servers, every millisecond counts. Here’s how to squeeze real performance gains from SSH and SCP on Linux. Choose the Right Cipher Cipher selection has the biggest impact on throughput. Modern CPUs have AES-NI hardware acceleration,…