Boot Startup

Common Problems 116064

Ubuntu 26.04 LTS – GRUB menu hidden and cannot select older kernel – Fix & Prevention

🟡 Medium   ⏱ 5–30 min  Last verified: 2 August 2026 Affected versions: Ubuntu 26.04 LTS 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors […]

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How to Set Up SSH Key-Based Authentication on RHEL 10 — step-by-step RHEL 10 tutorial on Progressive Robot

How to Set Up SSH Key-Based Authentication on RHEL 10

Introduction This tutorial demonstrates how to Set Up SSH Key-Based Authentication on RHEL 10 on RHEL 10. It is written for administrators who want a repeatable, well-explained walkthrough that goes beyond a bare command list and explains each configuration choice. Every command is tested against a freshly registered RHEL 10 system with the default AppStream […]

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How to Set Up NFS Server and Client on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Set Up NFS Server and Client on FreeBSD 15

Introduction Deploying set up nfs server and client on a FreeBSD 15 machine differs from Linux in several important ways: packages come from the FreeBSD Ports Collection or the binary pkg repository, services are registered in /etc/rc.conf via sysrc(8), and firewall rules are written in pf.conf(5) syntax. This tutorial stays entirely within the standard base […]

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How to Install Prometheus on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Install Prometheus on FreeBSD 15

Introduction How to Install Prometheus on FreeBSD 15 is a core administration task for any FreeBSD 15 server operator. FreeBSD 15 ships with the 15.0-RELEASE kernel, ZFS as the default root filesystem, Capsicum capability sandboxing improvements, and an updated ports tree. Unlike Linux distributions, FreeBSD uses rc(8) for service management, pf for packet filtering, and […]

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How to Install and Configure Rundeck on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Install and Configure Rundeck on FreeBSD 15

Introduction FreeBSD 15 is a UNIX-derived operating system renowned for its network stack performance, ZFS integration, and Jail isolation primitives. Setting up install and configure rundeck on FreeBSD 15 follows the rc.conf/service(8) paradigm rather than systemd, which means enabling a service and configuring its startup options are done differently from any Linux distribution. This guide […]

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How to Configure Buildbot CI on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Configure Buildbot CI on FreeBSD 15

Introduction Deploying configure buildbot ci on a FreeBSD 15 machine differs from Linux in several important ways: packages come from the FreeBSD Ports Collection or the binary pkg repository, services are registered in /etc/rc.conf via sysrc(8), and firewall rules are written in pf.conf(5) syntax. This tutorial stays entirely within the standard base + ports approach […]

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How to Schedule Backups with restic on RHEL 10 — step-by-step RHEL 10 tutorial on Progressive Robot

How to Schedule Backups with restic on RHEL 10

Introduction RHEL 10 ships with a stable, security-hardened base that makes deploying schedule backups with restic both straightforward and auditable. This tutorial covers the complete procedure for how to Schedule Backups with restic on RHEL 10, including dnf module streams where applicable, systemd unit management, and the firewalld rules required for network-facing services. Prerequisites The […]

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How to Install and Configure Cassandra on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Install and Configure Cassandra on FreeBSD 15

Introduction Deploying install and configure cassandra on a FreeBSD 15 machine differs from Linux in several important ways: packages come from the FreeBSD Ports Collection or the binary pkg repository, services are registered in /etc/rc.conf via sysrc(8), and firewall rules are written in pf.conf(5) syntax. This tutorial stays entirely within the standard base + ports […]

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How to Install and Configure Tomcat 10 on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Install and Configure Tomcat 10 on FreeBSD 15

Introduction This guide explains how to Install and Configure Tomcat 10 on FreeBSD 15 on FreeBSD 15. FreeBSD uses the pkg(8) binary package manager, rc.conf(5) for service startup configuration, and pf(4) as its primary packet filter. There is no SELinux or AppArmor — instead, FreeBSD provides the MAC (Mandatory Access Control) framework and Capsicum for […]

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How to Install MongoDB on FreeBSD 15 — step-by-step FreeBSD 15 tutorial on Progressive Robot

How to Install MongoDB on FreeBSD 15

Introduction Deploying install mongodb on a FreeBSD 15 machine differs from Linux in several important ways: packages come from the FreeBSD Ports Collection or the binary pkg repository, services are registered in /etc/rc.conf via sysrc(8), and firewall rules are written in pf.conf(5) syntax. This tutorial stays entirely within the standard base + ports approach so […]

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