Tag: #리눅스
Writing on GPUs, LLMs, MLOps, Kubernetes — and mindset · 10 posts
Processes and Signals, the Complete Guide: Tracing Why a Process Will Not Exit
Signal numbers and default actions, the difference between SIGTERM and SIGKILL, zombies and orphans, process groups and sessions, nohup and setsid, and how to design a graceful shutdown. Traces the cause of a process tha
2026-08-15 · 18 min read #리눅스#프로세스#시그널#운영#커널A Complete Guide to Linux Performance Tools: How to Read the Numbers in the Output
Interprets the numbers printed by top, vmstat, iostat, pidstat, sar and perf one column at a time. Covers which tool answers which question, which values create optical illusions, and the order in which to choose a tool
2026-08-15 · 18 min read #리눅스#성능#모니터링#운영#sysstatA Complete Guide to File Descriptors and Inodes: What Happens When df and du Disagree
Starts from the relationship between inodes and directory entries and works through hard links, deleted-but-still-open files, inode exhaustion, and file descriptor limits. Covers why df and du diverge and how to recover,
2026-08-15 · 16 min read #리눅스#파일시스템#inode#파일디스크립터#운영The complete guide to SSH operations: from key management to hardening a server without locking yourself out
sshdconfig hardening, choosing and distributing key types, ProxyJump and port forwarding, and the layered order to debug a connection that will not come up, organised from an operator viewpoint. Includes the procedure th
2026-08-15 · 17 min read #리눅스#ssh#보안#운영#서버관리The complete Linux troubleshooting command guide: from the first 60 seconds to root cause
The diagnostic commands to run, in order, from the moment someone tells you a server is misbehaving. uptime, top, free, df, iostat, ss, journalctl — which number in each output to read, and what that number rules out ver
2026-08-15 · 19 min read #리눅스#트러블슈팅#운영#장애대응#명령어A complete guide to Linux firewalls and access control: handling nftables, firewalld, and ufw without locking yourself out
Starts from the structure of nftables and lays out what firewalld and ufw do on top of it. Covers the procedure that keeps you from locking yourself out while changing rules remotely, and the diagnostic order for when ru
2026-08-15 · 18 min read #리눅스#방화벽#nftables#firewalld#보안The complete backup and restore guide: designing backwards from the recovery scenario
Starting from RPO and RTO, the criteria for choosing between rsync, tar, LVM snapshots, and snapshot-based backup tools. Covers the recovery rehearsal procedure and the five ways a backup quietly rots.
2026-08-15 · 16 min read #리눅스#백업#복구#재해복구#운영The Complete Guide to TLS Certificates: Handling Them End to End with openssl
A purpose-by-purpose reference of the openssl commands for reading certificates, creating CSRs, verifying chains, converting formats, and diagnosing server connections. Also covers how to identify expiry, a missing chain
2026-08-15 · 18 min read #리눅스#tls#인증서#openssl#보안The complete guide to Linux log operations: tying journald, rsyslog, and logrotate into one system
Designing the log plumbing of a Linux host, from journal retention policy to forwarding into rsyslog to the rotation modes of logrotate. Sets out the criteria for keeping the records an incident investigation needs witho
2026-08-15 · 16 min read #리눅스#로그#journald#rsyslog#logrotateThe Complete Guide to DNS: Following a Name All the Way to an Address
Splits name resolution into five separate segments — stub resolver through authoritative server — and works through record types, TTL and caching, delegation, reading dig output, propagation delay and stale caches, DNSSE
2026-08-15 · 25 min read #리눅스#dns#네트워크#운영#트러블슈팅