Amazon S3 has a maximum object size of 5TB per object. This limit applies uniformly across all storage classes and regions — there are no exceptions or workarounds. Understanding the 5TB Ceiling The 5TB limit is a hard constraint at the API level. You cannot upload, copy, or restore an object larger than this. While…
If you’re working with legacy BIOS systems and MBR partition tables, Fedora’s installer can sometimes misdetect your firmware mode and attempt UEFI/GPT setup on hardware that only supports legacy BIOS. This guide covers the proper approach for Fedora 39+ on MBR systems. Prerequisites Before starting, verify your system configuration: Boot the installer in legacy BIOS…
For any current Windows system, netsh winhttp is the standard command-line tool for proxy configuration. WinHTTP handles system-level proxy settings used by Windows Update, built-in applications, and services that don’t rely on browser-specific configuration. Set a proxy with bypass list netsh winhttp set proxy proxy-server=”proxy.example.com:8080″ bypass-list=”localhost;127.0.0.1;*.internal.local” Use semicolons to separate multiple proxy servers or bypass…
Thunderbird stores message filters in per-account configuration files, making it inconvenient to replicate filters across multiple accounts or installations. Rather than recreating filters manually, you can copy filter files directly or use symbolic links to keep filters synchronized. Where Thunderbird Stores Filters Thunderbird saves filter rules in msgFilterRules.dat, a plain text configuration file. Each account…
Broken symbolic links accumulate over time and can cause confusion or errors when scripts rely on their targets. Identifying and cleaning them up is a regular maintenance task. Basic approach Use find with the -xtype l test to locate broken symlinks: find /path/to/directory -xtype l The -xtype l flag specifically matches symbolic links that point…
This is fundamentally a decision about display technology and your reading habits. Here’s what you need to know. Display Technology The standard Kindle uses e-ink technology with a backlit display that requires external light sources — sunlight, a lamp, or overhead lighting. It’s readable but not ideal for low-light conditions. The Paperwhite adds a front-lit…
By default, WordPress contributors can submit and edit their own posts, but they can’t upload media files. If you want contributors to attach images or documents to their submissions, you’ll need to grant them the upload capability. Method 1: Using User Role Editor Plugin The User Role Editor plugin is the most straightforward approach for…
By default, libvirt stores VM images as files in /var/lib/libvirt/images/. While functional, this approach limits flexibility. LVM (Logical Volume Management) provides better control over disk space, snapshots, and performance tuning. Using LVM volumes as libvirt storage pools lets you manage VM storage like block devices rather than files, giving you faster provisioning, atomic snapshots, and…
When deprovisioning Linux VMs in public cloud environments, disk blocks may be reallocated to other customers if the provider doesn’t properly wipe storage. This is a legitimate concern for security audits, compliance validation, and understanding data exposure risks. Quick Recovery Method The most straightforward approach uses dd and strings to extract readable data from block…
When you need to store form submissions where different form types have different attributes, you’re essentially implementing an Entity-Attribute-Value (EAV) model. This is a common pattern for flexible schemas, but it requires careful design. The Core Problem You have multiple form types (Laptop, Mobile, Tablet) with different fields. A naive approach is a wide table…
To check which storage engine a table uses, query the information_schema database: SELECT ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA = ‘database_name’ AND TABLE_NAME = ‘table_name’; Replace database_name and table_name with your actual values. You can also use the SHOW TABLE STATUS command for a quicker view: SHOW TABLE STATUS FROM database_name WHERE Name = ‘table_name’\G The…
Database corruption happens. Whether it’s from unexpected shutdown, filesystem errors, or hardware issues, knowing how to recover from backups is essential sysadmin knowledge. When to Use Backups vs. Native Repair Tools Before jumping to restore from backup, consider your options: Native repair tools (REPAIR TABLE, CHECK TABLE) are faster and preserve recent data Backup restoration…
Facebook’s engineering team has long been vocal about their heavy reliance on MySQL to power one of the world’s largest platforms. Understanding their approach offers valuable insights for anyone managing databases at scale. Storage Engine Philosophy Facebook treats MySQL as a generic data manipulation and storage engine rather than a monolithic application database. This architectural…
A MySQL table marked as crashed typically occurs after unclean shutdowns, power failures, or server crashes. Error 145 indicates the table structure is corrupted and needs repair before queries can proceed. Checking Table Status Before attempting repair, check the table status: CHECK TABLE mybb_sessions; This returns detailed information about corruption. Common status values: OK —…
NoSQL databases have matured considerably and now handle a significant portion of production workloads. The landscape has shifted toward specialized solutions rather than one-size-fits-all approaches. Here’s a breakdown of the most widely deployed options: Document Stores MongoDB remains the most popular document database. It’s production-ready, well-documented, and offers strong consistency guarantees with replica sets. The…
SQL layers abstract traditional relational query interfaces over distributed NoSQL and big data systems, enabling applications to leverage SQL’s familiarity while benefiting from horizontal scalability. Here are the key approaches and systems that have emerged in this space. Distributed SQL on Key-Value Stores Phoenix (Apache Phoenix) provides a SQL interface over HBase. It compiles SQL…
When a disk fails on a server with multiple drives, you need to identify which physical SATA port it’s connected to. Linux device names (sda, sdb, etc.) don’t necessarily map to SATA port order, especially after disk failures or in systems with mixed storage. Using lsblk with Device Paths The lsblk command provides a quick…
MySQL Cluster uses NDB (Network Database) storage engine to provide high availability and data redundancy across multiple nodes. This guide covers installation and configuration on modern RHEL-compatible systems. Prerequisites Three or more servers (minimum: one management node, two data nodes, one SQL node) Rocky Linux 9 or AlmaLinux 9 Root or sudo access Static IP…
Swap space is essential for system stability, allowing the kernel to move less-frequently-used memory pages to disk when physical RAM is exhausted. Here’s how to set up a dedicated swap partition. Step 1: Create the Partition Use fdisk, gdisk (for GPT disks), or parted to create a new partition. For modern systems with GPT partition…
ANSI C is the standardized version of C defined in 1989, specifying the language’s syntax and semantics formally through a grammar. Understanding this grammar is essential for building tools that parse, analyze, or transform C code. Grammar Basics The ANSI C grammar is defined using Backus-Naur Form (BNF), a notation for specifying formal grammars. The…