RYZHOV / Linux
A working reference for Linux

Linux Resource Library

Selected Linux documentation for developers and operators: packages, services, networking, storage, performance, containers, ARM64, and shell tools.

48 selected references8 practical topics1 tested troubleshooting guide
48 resources

Resolve repository configuration, inspect packages, and understand signature checks.

  • APT source definitions

    Compare .list lines and Deb822 .sources stanzas when a repository appears twice or its options disagree.

    ReferenceDebian / APTmanpages.debian.org
    APT 2.6.1 · Debian 12 · Distribution reference · Selection reviewed
  • APT archive authentication

    Understand the archive trust chain and distinguish source configuration errors from failed signature verification.

    ReferenceDebian / APTmanpages.debian.org
    APT 2.6.1 · Debian 12 · Distribution reference · Selection reviewed
  • Debian package management handbook

    Choose the right package-management tool and investigate package states, dependencies, upgrades, and repository priorities.

    HandbookDebianwww.debian.org
    Maintained Debian Reference · Distribution reference · Selection reviewed
  • RPM reference manual

    Look up package queries, file ownership checks, and verification options before manipulating installed RPM packages.

    ReferenceRPM Projectrpm.org
    RPM 6.0 · compare installed version · Project documentation · Selection reviewed
  • DNF5 command reference

    Find repository, dependency, history, and transaction commands for Fedora systems using DNF5.

    ReferenceDNF Projectdnf5.readthedocs.io
    DNF5 · upstream latest · Project documentation · Selection reviewed
  • Zypper manual

    Check repository refresh, package selection, and solver options on openSUSE; verify options against the installed Zypper manual.

    ReferenceopenSUSEgithub.com
    Zypper · upstream development manual · Project documentation · Selection reviewed

Trace failed units, boot dependencies, journal messages, and service permissions.

  • systemctl: inspect and control units

    Inspect a unit's state and configuration, and distinguish reloading manager configuration from restarting a service.

    Referencesystemd / Debianmanpages.debian.org
    systemd 252 · Debian 12 · Distribution reference · Selection reviewed
  • journalctl: focus the evidence

    Filter the journal by service, boot, priority, and time when a failure is hidden in unrelated log messages.

    Referencesystemd / Debianmanpages.debian.org
    systemd 252 · Debian 12 · Distribution reference · Selection reviewed
  • Service startup and restart behavior

    Interpret service types, startup commands, timeouts, and restart behavior when a daemon exits or never becomes ready.

    Referencesystemd / Debianmanpages.debian.org
    systemd 252 · Debian 12 · Distribution reference · Selection reviewed
  • Service execution environment

    Investigate working directories, users, environment files, resource restrictions, and sandbox settings that affect a service process.

    Referencesystemd / Debianmanpages.debian.org
    systemd 252 · Debian 12 · Distribution reference · Selection reviewed
  • Unit dependencies and ordering

    Separate requirement dependencies from startup ordering and understand how drop-ins modify an existing unit.

    Referencesystemd / Debianmanpages.debian.org
    systemd 252 · Debian 12 · Distribution reference · Selection reviewed
  • Analyze boot and unit configuration

    Inspect boot timing and validate unit definitions; use the results as evidence rather than treating the longest duration as proof of a fault.

    Referencesystemd / Debianmanpages.debian.org
    systemd 252 · Debian 12 · Distribution reference · Selection reviewed

Separate DNS, routes, listeners, TLS, SSH, and firewall problems.

  • OpenSSH manual collection

    Check client and server configuration, authentication, forwarding, and file-transfer behavior. Match features to the installed release.

    ReferenceOpenSSHwww.openssh.org
    Upstream development manuals · Project documentation · Selection reviewed
  • ip: addresses, links, and routes

    Choose the address, link, route, or rule subcommand to inspect where the kernel will send a packet.

    Referenceiproute2 / man7.orgman7.org
    Linux iproute2 · Project documentation · Selection reviewed
  • nftables project wiki

    Learn tables, chains, hooks, and ruleset inspection before changing packet filtering on a remote host.

    HandbookNetfilter Projectwiki.nftables.org
    nftables · upstream wiki · Project documentation · Selection reviewed
  • dig: query DNS deliberately

    Select the record type and DNS server explicitly when comparing A, AAAA, authoritative, and recursive answers.

    ReferenceISC BINDbind9.readthedocs.io
    BIND 9 · stable documentation · Project documentation · Selection reviewed
  • Nginx listen directive

    Check address, port, default-server, and IPv6 socket settings when DNS resolves but an HTTP connection fails.

    ReferenceNginxnginx.org
    Upstream HTTP core module · Project documentation · Selection reviewed
  • curl command-line reference

    Build a repeatable HTTP diagnostic with explicit address family, timeouts, response headers, and TLS verification.

    Referencecurl Projectcurl.se
    Current curl · check local version · Project documentation · Selection reviewed

Map disks and mounts, understand filesystems, and plan a verifiable restore.

  • lsblk: map block devices

    Inspect the relationship between disks, partitions, and filesystems; select output columns explicitly for scripts.

    Referenceutil-linux / man7.orgman7.org
    Linux util-linux · Project documentation · Selection reviewed
  • findmnt: inspect mounted filesystems

    Identify the source, target, and options of a mount when an application is writing to an unexpected filesystem.

    Referenceutil-linux / man7.orgman7.org
    Linux util-linux · Project documentation · Selection reviewed
  • Btrfs administration documentation

    Look up subvolume, snapshot, scrub, and recovery concepts before choosing a Btrfs maintenance operation.

    HandbookBtrfs Projectbtrfs.readthedocs.io
    Upstream latest · btrfs-progs · Project documentation · Selection reviewed
  • ext4 administration guide

    Understand ext4 mount options and implementation details; compare kernel version before applying a setting.

    ReferenceLinux Kerneldocs.kernel.org
    Current upstream kernel documentation · Project documentation · Selection reviewed
  • Restore files with restic

    Recover a snapshot into a separate destination and explore backed-up files when rehearsing a restore.

    Guiderestic Projectrestic.readthedocs.io
    restic · stable documentation · Project documentation · Selection reviewed
  • Borg backup quick start

    Follow the repository, archive, inspection, and extraction workflow before designing a recurring backup routine.

    GuideBorgBackupborgbackup.readthedocs.io
    Borg · stable documentation · Project documentation · Selection reviewed

Find CPU, memory, storage, and scheduling bottlenecks with evidence.

  • The USE method

    Organize an investigation around utilization, saturation, and errors so measurements answer a specific resource question.

    GuideBrendan Greggwww.brendangregg.com
    Author's performance methodology · Author guide · Selection reviewed
  • procfs: process and system counters

    Interpret the interfaces under /proc and follow the detailed pages for the counters a monitoring tool reports.

    ReferenceLinux man-pagesman7.org
    Linux kernel userspace interface · Project documentation · Selection reviewed
  • ps: select process evidence

    Select process fields and formatting deliberately when investigating states, threads, elapsed time, or ownership.

    Referenceprocps-ng / man7.orgman7.org
    Linux procps-ng · Project documentation · Selection reviewed
  • sysstat: interval and historical statistics

    Choose among sar, iostat, mpstat, and pidstat for interval and historical measurements, and follow project documentation for each tool.

    Referencesysstat Projectsysstat.github.io
    sar, iostat, mpstat and pidstat · Project documentation · Selection reviewed
  • perf profiling examples

    Choose a counting, sampling, or tracing approach and understand what a profile does and does not measure.

    GuideBrendan Greggwww.brendangregg.com
    Author's Linux perf examples · Author guide · Selection reviewed
  • BPF kernel documentation

    Read the kernel's BPF concepts and interfaces when investigating tracing capabilities, verifier behavior, or program types.

    ReferenceLinux Kerneldocs.kernel.org
    Current upstream kernel documentation · Project documentation · Selection reviewed

Choose isolation, run rootless workloads, and build disposable test environments.

  • Podman documentation

    Look up rootless containers, pod operations, networking, and command behavior for the Podman release on your host.

    ReferencePodman Projectdocs.podman.io
    Upstream latest · compare installed version · Project documentation · Selection reviewed
  • Docker Engine documentation

    Understand the engine, storage, networking, and security model before running a service or building a test environment.

    HandbookDockerdocs.docker.com
    Docker Engine · maintained documentation · Project documentation · Selection reviewed
  • QEMU system emulation

    Choose a machine model, accelerator, block device, and network backend for an isolated guest; check stable-release support.

    ReferenceQEMU Projectwww.qemu.org
    Development branch · master · Project documentation · Selection reviewed
  • libvirt domain XML reference

    Inspect the declared CPU, disks, interfaces, and devices when a managed virtual machine differs from expectations.

    Referencelibvirt Projectlibvirt.org
    Current upstream domain format · Project documentation · Selection reviewed
  • systemd-nspawn system containers

    Check machine-container options, boot behavior, and filesystem boundaries for a disposable Linux userspace.

    Referencesystemd / Debianmanpages.debian.org
    systemd 252 · Debian 12 · Distribution reference · Selection reviewed
  • OCI runtime specification

    Trace container lifecycle and configuration requirements when debugging behavior beneath a high-level container CLI.

    SpecificationOpen Container Initiativegithub.com
    Development branch · main · Project documentation · Selection reviewed

Check board configuration, boot behavior, remote access, and architecture support.

  • Raspberry Pi hardware documentation

    Identify hardware interfaces and model differences before assuming a peripheral or power arrangement is supported.

    ReferenceRaspberry Piwww.raspberrypi.com
    Board-specific · check model · Project documentation · Selection reviewed
  • Raspberry Pi config.txt reference

    Look up boot-time firmware settings and conditional filters before changing a board's configuration.

    ReferenceRaspberry Piwww.raspberrypi.com
    Firmware settings · check model and OS · Project documentation · Selection reviewed
  • Raspberry Pi OS configuration

    Find supported system configuration procedures, including networking and display settings, for Raspberry Pi OS.

    HandbookRaspberry Piwww.raspberrypi.com
    Raspberry Pi OS · release-dependent · Project documentation · Selection reviewed
  • Raspberry Pi remote access

    Set up and diagnose remote access using the operating system's documented SSH and remote-desktop workflows.

    GuideRaspberry Piwww.raspberrypi.com
    Raspberry Pi OS · Project documentation · Selection reviewed
  • The Linux ARM64 boot contract

    Check kernel entry conditions, memory layout, and bootloader responsibilities when bringing up an ARM64 system.

    SpecificationLinux Kerneldocs.kernel.org
    ARM64 kernel / bootloader interface · Project documentation · Selection reviewed
  • Debian 13 ARM64 installation guide

    Check supported hardware and installation methods for Debian ARM64; architecture support does not imply every board boots identically.

    HandbookDebianwww.debian.org
    Debian 13 · ARM64 hardware support varies · Distribution reference · Selection reviewed

Look up command behavior, shell syntax, system calls, and kernel interfaces.

  • Bash reference manual

    Resolve quoting, expansion, redirection, and shell-control questions before relying on a command in a script.

    ReferenceGNU Bashwww.gnu.org
    Current GNU Bash · Project documentation · Selection reviewed
  • GNU Coreutils manual

    Check the precise behavior of common file, text, and checksum utilities, including options that differ across operating systems.

    ReferenceGNU Coreutilswww.gnu.org
    GNU utilities · not BSD command variants · Project documentation · Selection reviewed
  • Git command documentation

    Consult command semantics, revisions, and configuration when repository behavior needs a precise explanation.

    ReferenceGit Projectgit-scm.com
    Version-selectable Git manuals · Project documentation · Selection reviewed
  • GNU Make manual

    Understand dependency evaluation, variable expansion, recipes, and parallel execution when a build behaves unexpectedly.

    ReferenceGNU Makewww.gnu.org
    GNU Make · not all make implementations · Project documentation · Selection reviewed
  • Linux man-pages collection

    Find the correct manual section for an interface and distinguish kernel behavior from a similarly named command.

    ReferenceLinux man-pages / man7.orgman7.org
    System calls, libraries and selected tools · Project documentation · Selection reviewed
  • Linux kernel administrator guide

    Look up kernel parameters, reporting procedures, and subsystem administration; verify compatibility with the running kernel.

    HandbookLinux Kerneldocs.kernel.org
    Current upstream kernel documentation · Project documentation · Selection reviewed

How this library is selected

References are selected for a concrete operational task, with preference for project and distribution documentation. Annotations describe when to use a source; version labels make its scope explicit.

Selection reviewed means the destination, subject, and version scope were checked. It is not a claim that every upstream command has been tested. Original guides identify their own test environment. Platform filters also include references that apply across distributions.