This guide explains why backing up GitLab as a pure Git repository is useful, compares the git clone --mirror method with GitLab's built‑in Rake backup, details how to back up critical configuration files, and offers practical automation tips for a robust, multi‑layered backup strategy.
This article examines common log‑management anti‑patterns—such as copy‑truncate rotation, NAS storage, multi‑process writes, file‑hole creation, frequent overwrites, and Vim edits—explains why they cause data loss or duplicate collection, and offers practical best‑practice recommendations for reliable log handling in cloud‑native environments.
This article compiles a comprehensive matrix of 58 mainstream operations tools—covering operating systems, open‑source mirrors, containers, AI‑assisted ops, basic services, databases, monitoring, automation, CI/CD and service mesh—to help engineers quickly locate the right technology stack for efficient infrastructure management.
This article explains what inventory turnover is, why it matters for cash flow and operational efficiency, and provides a three‑step framework—data dashboards, product rhythm management, and supply‑chain coordination—plus three key monitoring practices (trend, product, people) to continuously improve warehouse performance.
When the built‑in elastic user password is lost in Elasticsearch 8.x or 9.x, you can use the official elasticsearch‑reset‑password command‑line tool to generate or set a new password without restarting the service, following a few simple steps and troubleshooting tips.
A collection of startling operational mishaps—from a disastrous database expansion during a sales event to a Kubernetes storage blunder, a misconfigured ESXi host, a company‑wide Excel crash, and a power‑maintenance disaster that fried servers—illustrates the critical importance of proper procedures, backups, and infrastructure monitoring.
This article explains why procurement teams often get blamed when supply chain issues arise and outlines a practical, step‑by‑step framework—including standardized demand entry, automated approvals, consistent pricing comparisons, clear contract delivery nodes, and closed‑loop payment—to create a transparent, efficient procurement system.
Effective log management is crucial for cloud‑native observability, yet common practices like copy‑truncate rotation, NAS storage, multi‑process writes, file‑hole creation, frequent overwrites, and vim edits can cause data loss or duplicate collection; adopting create‑mode rotation, local disks, append‑only writes, and proper tools mitigates these risks.
This article walks through troubleshooting a failed deployment caused by a full disk, showing how to use df -h to check overall disk usage and various du options (including --max-depth and -sh) to pinpoint large directories and resolve the issue.
This comprehensive guide walks you through installing HAProxy via yum, RPM packages, or source compilation, then details every core configuration block—including global, defaults, frontend, backend, and listen sections—while covering load‑balancing algorithms, ACL routing, health checks, SSL termination, statistics, and practical code examples for building a robust, high‑performance load‑balancer.
This article offers ops professionals a comprehensive roadmap to boost technical expertise, embrace AI and big‑data trends, and cultivate personal habits such as health, finance, communication, and hobbies, turning weekend time into a powerful engine for career resilience and lifelong fulfillment.
The 25th GOPS Global Operations Conference in Shenzhen showcased Guoxin Securities' senior manager Lin Ying presenting a four‑stage CMDB development journey, a comprehensive data‑governance solution, real‑world case study, and future outlook, highlighting practical insights for digital transformation in operations.
This article outlines a comprehensive, financial‑grade security blueprint for a three‑person operations team using AWS services such as IAM, Secrets Manager, Session Manager, GuardDuty, and WAF, emphasizing Zero Trust, Least Privilege, and Defense‑in‑Depth to protect against external attacks, internal risks, and to enable clear audit trails for incident investigation.
This article provides a comprehensive, hands‑on guide to installing HAProxy, configuring global, defaults, listen, frontend, and backend sections, setting up ACL‑based load balancing, preparing backend web servers, testing the setup, and accessing the HAProxy statistics page.
This article dives deep into ServiceMonitor, comparing it with traditional Prometheus configurations, detailing its core fields, and providing hands‑on examples for Harbor and GitLab metrics, enabling you to create stable, flexible, and maintainable monitoring setups for Kubernetes services.
This article explores how the rapid rise of large language models and techniques like Retrieval‑Augmented Generation, Chain‑of‑Thought prompting, and multi‑agent architectures can dramatically improve the speed, accuracy, and automation of fault localization in modern operations environments.
This guide shows how to map a low‑level containerd task ID to the corresponding Kubernetes Pod using ctr, kubectl, and jq commands, then provides step‑by‑step debugging actions such as pod inspection, log retrieval, and resource checks to quickly resolve container issues.
On June 6, 2025 Alibaba Cloud experienced a widespread DNS resolution failure affecting OSS, CDN, container image services and more, which was later linked to a Shadowserver sinkhole, and the article outlines the incident timeline, root‑cause analysis, and practical mitigation steps for operators.
This article explains how Douyin, TikTok, Baidu, Alibaba Cloud and Tencent operate self‑built data centers with terabit‑level outbound bandwidth, details ByteDance's server count growth from tens of thousands to hundreds of thousands, and describes the CDN technologies that enable billions of users to stream smoothly.
HertzBeat is a powerful, agent‑less, open‑source real‑time monitoring and alerting platform that supports custom templates, high‑performance clustering, cloud‑edge collaboration, and a wide range of notification channels, making it ideal for modern cloud‑native operations.
This guide provides Kubernetes operators with a comprehensive, step‑by‑step troubleshooting manual covering pod, node, and cluster‑level issues, common pod states, exit‑code analysis, and practical commands such as kubectl describe, logs, top, and drain, enabling rapid diagnosis and resolution of K8s problems.
This article compiles practical advice from experienced operations engineers on the challenges and strategies for achieving a 300,000 CNY yearly salary, covering skill development, career moves, company size, automation, and the evolving role of SRE/DevOps.
This guide provides a comprehensive, step‑by‑step troubleshooting checklist for Kubernetes operations, covering Pod, Node, and cluster‑level problems, common pod status anomalies, and container exit‑code analysis to help operators quickly locate and resolve issues.
This article introduces Ceph as a leading open‑source distributed storage solution and presents a comprehensive operations manual covering common tasks, fault handling, and advanced topics to help engineers efficiently manage and troubleshoot Ceph clusters.
This article introduces Nginx UI, a graphical tool that simplifies Nginx configuration and monitoring, outlines its core features—including AI Agent support—provides pre‑installation notes, and offers step‑by‑step installation guides for Systemd, Docker, and quick‑install scripts, concluding with its operational benefits.
The article explains why warehouses can be overfilled while customers still face stockouts, analyzing false and structural overstock, flawed demand planning, weak supply chain execution, and offers practical steps such as data‑driven forecasting, ABC inventory classification, transparent collaboration, fast‑response mechanisms, and accountability to resolve the paradox.
This comprehensive guide walks you through designing a highly available Kubernetes cluster, covering multi‑master control‑plane deployment, worker‑node resilience, advanced networking with Cilium, durable storage with Rook/Ceph, monitoring with Thanos, security policies, disaster‑recovery strategies, cost control, and automated rollouts, all illustrated with concrete configuration snippets and real‑world performance results.
This guide explains how to manage systemd journal logs on Linux, covering persistent storage configuration, size limits, various journalctl commands for viewing service, user, command, and boot logs, as well as log rotation, vacuuming, and integrity verification.
This article presents JD's comprehensive methodology for digitally transforming large and medium-sized state-owned enterprises, outlining strategic phases, technology adoption, organizational changes, and implementation steps through a series of illustrative slides.
This article explains the differences between SLA, SLO, and SLI, shows how to express user expectations as concrete service level agreements, and introduces essential high‑availability metrics such as availability percentages, MTBF, MTTR, RPO, RTO, WRT, and MTD for reliable system design.
This article explains how to build a robust offline inventory counting system that prevents data loss, resolves synchronization conflicts, and ensures seamless operation even when network connectivity is interrupted, offering practical design patterns and pitfall‑avoidance tips for warehouse teams.
This article outlines a complete warehouse management SOP—from accurate receiving and scientific storage to efficient shipping, regular inventory checks, safety standards, and 5S principles—showing how to turn the warehouse into a reliable “bank” for the factory while boosting operational efficiency.
This comprehensive guide explains what supplier performance evaluation is, why it matters, and provides a step‑by‑step "3+1" framework—including metric definition, scoring methods, result grading, and system integration—to help organizations build a data‑driven, actionable SRM process that improves supply chain reliability and reduces costs.
The article introduces China’s System Operation Maturity Model (SOMM), detailing its three pillars—AIOps, SRE, and FinOps—along with the underlying standards, assessment results, and how enterprises leverage these frameworks to achieve smarter, more reliable, and cost‑effective IT operations.
This article explains the fundamentals of Layer‑4 and Layer‑7 load balancing, compares their advantages and disadvantages, and describes how a hybrid approach can combine high‑performance traffic handling with flexible application‑level routing for large‑scale systems.
This article presents a comprehensive overview of server fault management at scale, detailing the classification of failures, shortcomings of traditional manual processes, and the design of an automated detection and repair system that combines in‑band and out‑of‑band data collection, rule‑based alerting, and end‑to‑end repair workflows, while also outlining future directions for intelligent monitoring and reliability.
This article presents a comprehensive, source‑code‑derived list of every Elasticsearch configuration option—including hidden and undocumented settings—explains their scopes, default values, and types, and shows how the list can be used for quick lookups, performance tuning, debugging, and automation.
This article explains how AI agents enhance large‑model capabilities for AIOps, detailing single‑agent use cases like knowledge retrieval, tool guidance, and fault diagnosis, as well as multi‑agent collaborations, required skills, and future prospects for autonomous operations.
This guide explains how to use Nginx's HttpLogModule to control log output, defines key directives such as access_log, log_format, and open_log_file_cache, provides example configurations, demonstrates testing with curl, and offers practical tips for per‑location log management to improve troubleshooting and performance.
This guide walks through the required environment, Windows Server rsync installation, configuration of rsyncd.conf and password files, service startup, port verification, and client-side commands to achieve reliable, scheduled file synchronization between Windows machines.
This article explains how to overcome Dify's lack of built‑in scheduling and monitoring by integrating it with external task‑scheduling systems such as GitHub Actions and XXL‑JOB, detailing setup steps, limitations, and the advantages of using XXL‑JOB for precise, enterprise‑grade workflow automation.
This article explains what warehouse management really means, outlines its key goals such as safety, efficiency, supply‑chain coordination and data visualization, and presents six practical methods—including clear objectives, ABC classification, barcode usage, FIFO, space optimization, and digital automation—to dramatically improve warehouse performance.
This article explains how a SaaS company leveraged large language models to automatically ingest, enrich, and analyze stability alerts, turning noisy notifications into actionable insights through configurable pipelines, Feishu integration, and a streamlined AI workflow that boosts incident response speed and reduces manual effort.
This guide presents a curated collection of 20 practical Linux one‑liners—using awk, grep, netstat, and other shell tools—to extract IP counts, page views, bandwidth, error rates, concurrency, and other key metrics from Apache access logs, enabling quick and thorough server traffic analysis.
Six months after abandoning Kubernetes, our DevOps team reduced infrastructure spend by 62%, cut deployment time by 89%, eliminated weekend on‑call duties, and improved overall happiness, demonstrating that simplifying the tech stack can deliver substantial operational and business benefits.
This comprehensive guide covers core WMS terminology—from basic concepts like locations, storage slots, and SKUs to inbound/outbound processes, inventory management techniques such as FIFO and safety stock, strategic approaches including wave and picking methods, essential equipment like PDAs and RFID, and advanced industry jargon, providing product managers with the knowledge to navigate technical discussions, impress stakeholders, and optimize warehouse operations.
This article outlines common challenges in multi‑platform domain and HTTPS certificate management, introduces a unified management platform with features like automated syncing, Let’s Encrypt integration, and multi‑channel alerts, provides a step‑by‑step Docker deployment guide, and shares a curated collection of popular open‑source monitoring tools.
This article examines why most ERP projects in Chinese companies fail, explores the core benefits of ERP, identifies common pitfalls such as over‑complexity, resistance, and high costs, and offers practical steps—including need assessment, right‑sized selection, process clarification, phased rollout, and strong leadership—to ensure successful implementation.
This guide explains why every server must monitor CPU, memory, disk and network usage, shows how to clean disks and analyze traffic using command‑line utilities such as df, du, iotop, iostat, iftop, lsof and tcpdump, and provides real‑world case studies for troubleshooting disk space exhaustion, port conflicts and abnormal outbound traffic.
This guide shows how to integrate Jenkins with Prometheus and Grafana, covering plugin installation, metric endpoint exposure, Prometheus scraping configuration, verification via curl, and importing a ready‑made Grafana dashboard to achieve proactive, visualized CI/CD monitoring.
This article explains why Python is a leading language for DevOps automation, detailing its core advantages, typical use cases such as bulk server management, configuration management, log analysis, and scheduled tasks, and introduces common Python libraries and learning pathways for building robust operational workflows.
Chaos engineering is a discipline that deliberately injects faults into distributed systems to test and improve resilience, tracing its evolution from Netflix's Chaos Monkey to modern platforms, outlining its operational workflow, benefits, and core principles for reliable system design.
This article dissects the classic Eight Fallacies of Distributed Computing, explaining each mistaken assumption about network reliability, latency, bandwidth, security, topology, administration, cost, and homogeneity, and provides real‑world case studies and practical recommendations to help engineers design more resilient distributed systems.
Learn how to protect your services from abusive traffic and brute‑force attacks by using Nginx's rate‑limiting features—limit_req to control request rates and limit_conn to restrict concurrent connections—complete with configuration examples, explanations of zones, burst handling, custom error pages, and log monitoring.
The article introduces intelligent supply chain planning algorithms—including network design, inventory layout, and simulation—detailing their optimization models, high‑performance solving techniques, and real‑world impact on cost reduction, efficiency, and service experience across large‑scale logistics operations.
The 25th GOPS Global Operations Conference in Shenzhen announced the dual ITU DevOps international and domestic standard assessment results, highlighting Agricultural Bank as the first state bank to earn a five‑star internal coach talent rating and showcasing multiple financial institutions that have successfully passed BizDevOps and continuous delivery evaluations, underscoring the growing importance of standardized DevOps practices in China’s finance sector.
A collection of real‑world anecdotes from Zhihu users reveals servers and computers that have stayed online for decades, highlighting hardware longevity, power‑redundancy strategies, and the cultural mindset of “if it works, don’t touch it.”
The article explains Heinrich's Law, its 1:29:300 accident pyramid, and how applying its principles—tracking minor incidents, hidden hazards, and systemic risks—can help software teams anticipate, diagnose, and prevent major online failures through systematic safety management and data‑driven practices.
This technical case study details how a high‑traffic Kafka logging cluster was optimized by adjusting Filebeat and Kafka parameters, increasing compression batch size, and tuning Kubernetes settings, resulting in significant reductions in request volume, network traffic, CPU usage, and overall resource consumption.
This article introduces SigNoz, a self‑hosted open‑source observability platform that unifies metrics, logs, and traces, outlines its core capabilities, shows how to install it with Docker, and compares its resource efficiency to commercial solutions like DataDog and Elastic.
The article reveals how over‑eager replenishment creates supply‑chain avalanches, zombie inventory, and bullwhip effects, then offers a step‑by‑step resurrection guide with dynamic safety stock, data‑validation loops, and self‑healing mechanisms to restore healthy inventory flow.
This article explains why Kubernetes certificates often become hidden "time bombs," describes the typical failures caused by expired certificates, and provides practical methods to detect upcoming expirations and safely renew or replace them to keep clusters running smoothly.
This guide shows how to integrate Zabbix with a locally deployed DeepSeek large language model via Webhook, enabling automatic analysis of alert causes and solutions, feeding results back to operators through dashboards or enterprise WeChat, and dramatically reducing MTTR and manual effort.
A disastrous beauty‑ecommerce promotion exposed how naïve wave‑picking designs can turn warehouses into mazes, cause urgent orders to disappear, and mix products, but by applying intelligent grouping, dynamic capacity, heat‑map path optimization, and a three‑level priority system, fulfillment efficiency can be dramatically restored.
This guide explains the concepts, mechanisms, and primary uses of SNAT and DNAT in network address translation, and provides step‑by‑step iptables commands for implementing source and destination address translation in typical networking scenarios.
On March 21 2025, a mis‑deployed credential during R2 Gateway's key rotation caused a 1‑hour‑7‑minute outage that blocked all write operations and about 35% of reads across R2 and several downstream Cloudflare services, prompting a detailed post‑mortem and a set of corrective actions to improve visibility and safety of credential changes.
This article outlines the evolution of BizDevOps standards in China, detailing recent policy mandates, the expansion of the DevOps maturity model to organization‑level practice, the AI‑driven SOMM operation assurance framework, and the integration of large‑model AI into R&D and operational workflows, highlighting their impact on enterprise efficiency and governance.
The article analyzes the challenges of manually deploying Model Context Protocol (MCP) servers for AI agents, compares them with Docker‑based deployment, and demonstrates step‑by‑step configurations, code snippets, and concrete benefits such as environment consistency, resource efficiency, and security.
This article compiles twenty frequent operational incidents—from server inaccessibility and database connection errors to disk‑space exhaustion, high CPU usage, memory leaks, network latency, DNS failures, service crashes, file‑system corruption, update problems, permission misconfigurations, web‑server and email issues, backup failures, load‑balancing anomalies, firewall rule mistakes, SSH connection problems, database performance degradation, dependency gaps, and virtual‑machine faults—detailing their symptoms, step‑by‑step troubleshooting procedures, and concrete remediation actions.
This article details Baidu's log platform point‑governance practice, explaining why uncontrolled event logging inflates storage and compute costs, and describing a three‑stage solution—manual, semi‑automatic platform, and full‑lifecycle standardization—that uses anomaly detection, automated workflows, and IM bots to achieve massive PV reduction and annual cost savings.
The article details China’s push for international ITU DevOps standards, showcases Industrial and Commercial Bank of China’s successful BizDevOps dual‑certificate assessment, and presents an in‑depth Q&A with senior fintech managers discussing the value, challenges, and future roadmap of integrating business, development, and operations to accelerate digital transformation.
The article outlines the most important Linux log files located under /var/log, explains what each records—from system messages and authentication attempts to web server activity—and provides practical commands for viewing and alerting on critical entries to improve troubleshooting and security monitoring.
This collection gathers recent technical articles covering fault testing fundamentals, Byteman usage guides, and Chrome extension development tutorials, providing developers with practical insights, best practices, and hands‑on examples to improve system reliability, testing strategies, and front‑end extension capabilities.
At the 25th GOPS Global Operations Conference in Shenzhen, China Galaxy Securities showcased its successful dual certification under ITU DevOps standards, detailing the Bond Investment Business Support System's continuous testing achievements, pipeline integration, and the broader impact on financial DevOps practices.
The 25th GOPS Global Operations Conference in Shenzhen announced the dual ITU DevOps international and domestic standard assessment results, highlighting the Agricultural Bank of China's AAAAA‑level DevOps coach certification and showcasing multiple state‑owned banks, exchanges, and securities firms achieving leading domestic DevOps maturity across BizDevOps, continuous delivery, and continuous testing standards.
Changan Automobile’s full‑link observability platform passed both ITU DevOps international and domestic standards assessments, showcasing its advanced monitoring capabilities, improved system stability, and strategic role in the company’s digital transformation, while the interview reveals implementation challenges, benefits, and future AI‑driven enhancements.
The article details China's push for internationalized information standards, the CAICT's dual ITU DevOps and domestic assessments, and how the Shenzhen Stock Exchange successfully passed Level 3 continuous delivery evaluation, showcasing advanced DevOps capabilities and their alignment with national digital transformation policies.
The article details China Information Communication Institute’s dual ITU DevOps international and domestic standard assessment, ICBC’s successful BizDevOps certification for its Fast‑Loan project, and insights from senior fintech managers on the value, challenges, and future roadmap of integrating business, development, and operations to drive digital transformation.
This article analyzes common inventory discrepancy scenarios, exposes typical blame‑shifting tactics across departments, and presents a comprehensive, operation‑focused solution stack—including traceability, dynamic calibration, and fool‑proof design—to eliminate errors and improve accountability.
This tutorial walks through installing Docker and Jenkins on CentOS, configuring system settings, creating a Jenkins job to pull, build, and package a Spring Boot project, testing the pipeline, and finally running the application via Docker, providing complete commands and configuration details for a reliable CI/CD workflow.
This article explains why many companies struggle with fragmented supply‑chain processes, outlines the three essential capabilities of a truly effective SCM system—smooth workflow, node monitoring, and data persistence—and details how such a system can transform procurement, warehousing, logistics, cross‑department collaboration, and data analysis into an automated, data‑driven operation.
The article analyzes common cron job failures such as accidental deletions, OOM crashes, and lack of monitoring, then proposes standardized Jenkins deployment, automatic server selection, lock mechanisms, queue-based processing, status awareness, and the use of the open‑source Healthchecks system to achieve proactive detection and alerting.
This guide shows how to integrate Zabbix with a locally deployed DeepSeek large language model via Webhook, enabling automatic analysis of alerts, generation of root‑cause explanations and remediation suggestions, and delivering results through WeChat bots, dashboards, or email to reduce MTTR and manual effort.
This guide compiles practical Linux shell commands for analyzing Apache and Nginx access logs, covering IP frequency, page request counts, status code distribution, traffic volume, crawler detection, subnet aggregation, and time‑based request rates to help administrators monitor web service health efficiently.
This guide compiles the most commonly used Docker commands, organized by functionality—including installation, image management, container handling, network and volume operations, logging, debugging, and system cleanup—to help developers and operations engineers efficiently manage Docker environments.
This article introduces Zabbix as a powerful open‑source monitoring solution, outlines its 7.0 features, architecture, installation and configuration steps, highlights recent enhancements, and explains how to obtain a free 2000‑page Chinese manual via QR code.
This article explains chaos engineering—its definition, core principles, experimental workflow, tool selection, AI‑driven enhancements, and practical case studies—providing a comprehensive guide for building resilient distributed systems across backend, cloud‑native, mobile, and AI‑enabled environments.
This article introduces the ten most frequently used operations engineering tools, detailing each tool's functions, suitable scenarios, advantages, and real‑world examples, and includes practical code snippets to help engineers automate and streamline their daily workflows.
By integrating large language models, Chatbox, MCP, and GraphQL, the TDMQ RocketMQ team enables operators to retrieve cluster, topic, and message data across heterogeneous sources using a single natural‑language query, dramatically simplifying diagnostics and reducing manual query effort.
This article introduces ten indispensable operations engineering tools—Shell scripts, Git, Ansible, Prometheus, Grafana, Docker, Kubernetes, Nginx, ELK Stack, and Zabbix—detailing their functions, suitable scenarios, advantages, and real‑world examples, plus sample code snippets to help engineers automate and monitor infrastructure efficiently.
An AWS EC2 instance behind an Elastic Load Balancer became unresponsive due to repeated TCP out‑of‑memory errors, which were resolved by examining kernel messages, adjusting tcp_mem‑related kernel parameters, and rebooting the server after a long uptime.
This article introduces Zabbix’s core features, flexible data collection, custom alerting, visualization, high‑availability architecture, security auditing, and compares it with Prometheus, then walks through a step‑by‑step installation, configuration, and deployment on a CentOS server.
This article dissects common failures in e‑commerce replenishment—such as hot‑product black holes, slow‑moving stock graves, and supply‑chain avalanches—and presents a seven‑step framework of dynamic forecasting, tiered strategies, distributed inventory, and automated safeguards to stabilize inventory levels.
This article explains why high‑throughput producers and consumers can saturate CPU, memory, network and disk I/O in TDMQ Pulsar clusters, describes the built‑in cluster‑level distributed and topic‑partition rate‑limiting mechanisms, and provides practical guidance for configuration, monitoring, and troubleshooting.
This guide explains how to set up HAProxy monitoring by configuring a Prometheus exporter, adding HAProxy targets to Prometheus, verifying metric collection, and visualizing the data in Grafana with a ready-made dashboard, ensuring reliable and performant services.
This guide explains how SRE teams should collaborate early in the software development lifecycle to define Service Level Indicators (SLIs), set realistic Service Level Objectives (SLOs) and Service Level Agreements (SLAs), and integrate observability signals, error budgeting, risk management, and incident handling into reliable operations.
This article explains what performance testing is, why it is essential for reliable systems, outlines practical steps for conducting effective tests, and introduces the wrk benchmarking tool as a lightweight solution for generating realistic load and measuring key performance metrics.
This article explains how to configure Nginx as a load balancer for web applications, covering upstream and proxy_pass definitions, the three built‑in balancing methods, weight and connection settings, fail‑over options, and practical code examples for both HTTP and HTTPS deployments.
This guide demonstrates how to use Ansible playbooks to copy a single file or multiple files from a source host to a target server, detailing the required YAML configuration, copy module parameters, and execution steps for reliable file deployment in automated operations.
This article explains the Linux boot sequence, covering the BIOS/UEFI hardware check, GRUB2 bootloader configuration, kernel loading with initramfs, root filesystem mounting, systemd target units, essential services, and a CentOS 8 example with GRUB settings and module inspection.
