Snaps bundle applications with their dependencies to work across distributions, but this isolation creates compatibility gaps. One common problem with Thunderbird snap is missing or incorrectly rendered fonts—a direct result of how fontconfig is handled inside the snap sandbox. Why Thunderbird snap doesn’t use system fonts Thunderbird snap includes its own fonts.conf located at ~/.var/app/com.thunderbird.Thunderbird/config/fontconfig/fonts.conf…
RSS feed readers have become essential for staying on top of content from multiple sources. If you’re switching from Feedly to Follow.it, the migration is straightforward — both services support OPML (Outline Processor Markup Language), a standard format for exporting and importing feed lists. Export Your Feed List from Feedly Feedly makes exporting your feeds…
DNF and YUM automatically download RPM packages and their dependencies during installation. If you need to build offline installation media, create local mirrors, or avoid repeated downloads across multiple systems, you’ll want to preserve those packages instead of letting them disappear from cache after installation. This is especially useful for: Building offline installation repositories Preparing…
Google shut down Feedburner’s management interface, leaving it in indefinite maintenance mode. While RSS remains a critical format for feed distribution across platforms like WordPress and other CMS software, you need an alternative service for feed management and subscriber tracking. follow.it is a solid Feedburner replacement that handles RSS feeds, subscriptions, and analytics. This guide…
In XML, CDATA (Character Data) sections let you include text without worrying about XML special characters. Everything inside <![CDATA[ and ]]> is treated as literal text — no parsing, no entity references. This is useful for embedding code snippets, scripts, or any content with lots of <, >, or & characters. The catch: you can’t…
When you’re managing KVM virtual machines on a Linux host, you often need to identify which OS threads correspond to vCPU threads. This is essential for CPU pinning, performance analysis, and troubleshooting resource contention. Using virsh to List vCPU Thread IDs The most straightforward approach is through virsh, libvirt’s command-line tool: virsh vcpuinfo <domain-name> This…
When running virtual machines with QEMU/KVM, you’ll frequently need to transfer files or share directories between the host and guest systems. Several methods work well depending on your use case and performance requirements. 9p (Virtio) Filesystem The 9p protocol is the most straightforward approach for sharing directories. It’s lightweight and doesn’t require additional guest agents….
If you’re seeing PHP errors like Class ‘DOMDocument’ not found, your PHP installation is missing the XML extension. This is common after migrating sites or fresh installations where the base PHP package doesn’t include DOM support out of the box. Install php-xml The solution is straightforward — install the php-xml package: sudo dnf install php-xml…
Short open tags (<? ?>) create compatibility issues with XML declarations and are considered poor practice. While they’re disabled by default in modern PHP versions, you may need to manage this setting when working with legacy code or specific server configurations. Configuration Methods Via php.ini The primary way to control short open tags is through…
Files with replication factor 1 are a liability in production HDFS clusters. They have no redundancy, meaning a single node failure results in data loss. Identifying and fixing these files should be part of your regular cluster maintenance. Using the HDFS CLI The most straightforward approach is using hdfs fsck with output parsing: hdfs fsck…
The HDFS NameNode holds the entire filesystem namespace and block map in memory. Estimating memory requirements accurately is critical for cluster planning and preventing out-of-memory failures that can cripple your entire cluster. Core Memory Components The NameNode’s memory consumption breaks down into several key areas: Namespace Objects: The NameNode maintains an in-memory representation of the…
After a libvirt upgrade, VMs fail to start with the error: error: Failed to start domain kvm1 error: Network not found: no network with matching name ‘default’ This happens when the default NAT network (virbr0) isn’t automatically created during the upgrade. Quick fix: Restore the default network The fastest solution is to recreate the default…
When you create VMs in KVM, they’re typically assigned IP addresses via DHCP. Finding those addresses so you can SSH in requires a few steps. Here are the practical approaches. Using virsh domiflist and ARP The traditional method combines virsh domiflist to get the VM’s MAC address, then looks it up in the ARP table:…
The YARN resource scheduler determines how cluster resources are allocated to jobs. By default, Hadoop uses the Capacity Scheduler, but you can switch to an alternative like the Fair Scheduler or configure different scheduling policies. Identifying Your Current Scheduler Check which scheduler is currently active by examining your configuration: grep -A 2 “yarn.resourcemanager.scheduler.class” $HADOOP_HOME/etc/hadoop/yarn-site.xml The…
Backing up text messages from Android works best through Google Messages for real-time web access, or via ADB and third-party tools for local archives. Your approach depends on whether you need cloud sync, local storage, or both. Google Messages for Web (Easiest) The simplest method for most users is Google Messages, which syncs SMS and…
When stop-dfs.sh fails to cleanly terminate DataNode processes, you’re left with orphaned Java processes consuming resources and potentially causing cluster issues. This happens most often after ungraceful cluster shutdowns or when the standard stop script encounters communication problems with specific nodes. Understanding the Problem The typical symptom is stop-dfs.sh reporting that certain nodes have no…
When uploading files to HDFS using hdfs dfs -put, the replication factor defaults to the cluster-wide setting in hdfs-site.xml (typically 3). For temporary files, logs, or staging data, you often want a lower replication factor to reduce write latency and disk usage. Override Replication Factor at Upload Time Use the -D flag to pass HDFS…
When you see output like this from hdfs dfsadmin -report, you need to understand what each metric means and how to respond: Under replicated blocks: 139016 Blocks with corrupt replicas: 9 Missing blocks: 0 Understanding block states in HDFS is essential for cluster health. The distinction between these categories determines how urgent your response needs…
When a NameNode restarts, it enters safe mode to rebuild its understanding of block-to-DataNode mappings. If DataNodes don’t report their blocks quickly enough or some don’t come back online, the NameNode may stay stuck in safe mode with a message like: The reported blocks 1968810 needs additional 5071 blocks to reach the threshold 0.9990 of…
Google+ shut down in 2019, so the original premise of this post no longer applies. However, the broader problem—automatically sharing blog RSS feeds across social platforms—remains relevant. Here’s how to handle RSS-to-social distribution in 2026. Modern RSS Distribution Tools For most technical blogs, you have several solid options: Zapier remains one of the most reliable…