Xen remains in production use (AWS EC2, Citrix Hypervisor), though KVM has become the standard Linux hypervisor. This guide covers automating backups for file-backed Xen virtual machines. The approach adapts to other hypervisors like KVM with minimal modification. Architecture and Prerequisites The backup system assumes: Virtual machines stored in /lhome/xen/ with individual directories per VM…
When using lftp to connect to FTP servers, you may encounter a stall with “Making data connection” after logging in: < — 227 Entering Passive Mode (xx,xx,xx,xx,xx,xx) —- Connecting data socket to (yy,yy,yy,yy) port zz `ls’ at 0 [Making data connection…] The connection hangs indefinitely, though other clients like FileZilla work fine on the same…
Accessing a remote desktop environment on a Linux server securely requires proper tunneling. While SSH X11 forwarding works for single applications, VNC provides a full graphical desktop session. By combining VNC with an SSH tunnel, you encrypt all traffic and can work around firewall restrictions that only allow port 22. Why VNC Over SSH? VNC…
DNS caching helps reduce lookups but sometimes you need to clear it after DNS changes, certificate updates, or to troubleshoot resolution issues. Modern Linux with systemd-resolved Most contemporary Linux distributions use systemd-resolved as the default DNS resolver. Flush the cache with: sudo systemctl restart systemd-resolved Or use the resolvectl command: sudo resolvectl flush-caches To verify…
Git and SSH integrate seamlessly for version control infrastructure. An SSH-based Git server works well for small teams where all members are trusted and have administrator-level access to all repositories. This approach is straightforward to deploy, but lacks fine-grained access control. For teams that need role-based repository access or audit trails, consider dedicated tools like…
DNS lookups can be a bottleneck in Firefox browsing performance. Here are practical methods to optimize DNS resolution and related network behavior. Disable IPv6 (if not needed) If your network doesn’t use IPv6, disabling it can eliminate unnecessary lookup delays. In Firefox, navigate to about:config and set these preferences: network.dns.disableIPv6 → true This prevents Firefox…
Xen remains a robust hypervisor for production environments—AWS EC2, Citrix Hypervisor, and many hosting providers still rely on it. However, KVM has become the default for most Linux distributions due to simpler management and better integration with standard tooling. For new deployments on standard Linux, evaluate KVM with libvirt or container solutions like Docker and…
After running on MediaWiki, we migrated back to WordPress. Both platforms have their strengths, but WordPress proved to be the better fit for our site’s goals. What WordPress Does Better for This Site Plugin Ecosystem and Content Discovery WordPress’s plugin landscape is significantly deeper than MediaWiki’s. The YARPP (Yet Another Related Posts) plugin and its…
Crontab controls what runs and when. Each crontab entry has this format: .—————- minute (0-59) | .————- hour (0-23) | | .———- day of month (1-31) | | | .——- month (1-12) OR jan,feb,mar,apr … | | | | .—- day of week (0-6) (Sunday=0 or 7) OR sun,mon,tue … | | | | |…
Gitosis provides a lightweight way to manage Git repositories and user access on a self-hosted server. This post covers user management, repository configuration, and access control. For initial server setup, refer to your Gitosis installation documentation. Adding a New User Each user needs an SSH key pair for authentication. The user generates their key locally:…
Gitosis is unmaintained and shouldn’t be used for new deployments. Use Gitolite or Forgejo instead. This guide covers Gitolite, which provides fine-grained access control, is actively maintained, and handles multiple repositories under a single system user. Prerequisites A server running Linux (Debian, Ubuntu, CentOS, or similar) SSH access to the server with sudo privileges A…
Archived Content (2010): This post describes a research project from 2010. The tools and versions mentioned (Hadoop 0.20, MapReduce Streaming) are historically significant but have been largely superseded by modern distributed build systems like Bazel Remote Execution and cloud-native CI/CD pipelines. mrcc – A Distributed C Compiler System on MapReduce Original Project Date: January 2010…