VirtualBox is free, open-source software for running multiple operating systems. Supports Windows, Linux, macOS, and Solaris. Provides disk encryption and user manual access
Ubuntu releases follow YY.MM format with 'Oracular Oriole' codename. LTS releases are published every two years in April, used by 95% of installations. LTS releases receive 5 years of standard security maintenance. Ubuntu Pro subscription offers 10 years of security maintenance. Interim releases are produced every six months, supported for 9 months
Pool.ntp.org is a global virtual cluster of NTP servers. Serves hundreds of millions of systems worldwide. Default time server for major Linux distributions. Maintained by Ask Bjørn Hansen and community contributors
Exit Code 127 indicates a command could not be found in Linux/Unix systems. Zero indicates success, non-zero values indicate errors. Part of a range of codes (126-165) used in Linux/Unix systems
Controller can be installed via Helm chart or kubectl apply with YAML manifests. Most Kubernetes clusters require no additional configuration. Helm installation creates ingress-nginx namespace if it doesn't exist
Ingress enables external access to Kubernetes services via HTTP/HTTPS. Traffic routing is controlled by rules defined in Kubernetes API. Ingress controller manages traffic, typically using load balancer