Tag: sysadmin
All the articles with the tag "sysadmin".
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strace for Beginners: See What Any Process Is Doing
Use strace to trace system calls and debug mysterious errors without reading source code.
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lsof: The Tool That Shows You Everything
Master lsof to find port conflicts, trace deleted files eating disk, and debug network connections.
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Docker Exit Codes: Why Your Container Keeps Restarting
Decode Docker exit codes: 0 (success), 1 (app error), 125/126/127 (Docker errors), 137 (OOM), 143 (SIGTERM). Debug restarts in minutes.
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CPU and I/O Priority with nice and ionice
Manage Linux process priority with nice (CPU) and ionice (I/O). Learn priority levels, renice running processes, and avoid tanking server performance.
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Linux File Descriptor Limits: When 1024 Isn't Enough
File descriptors and why that 1024 limit kills your server. How to check, raise, and debug fd exhaustion.
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Why Your Docker Logs Are Eating Your Disk
Docker's default JSON logging driver writes unbounded logs to disk. Learn how to set log rotation and reclaim your storage.
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The `at` Command: One-Time Scheduled Tasks in Linux
Schedule one-off Linux tasks with `at` instead of cron. Learn syntax, queue management, batch jobs, and when to use it for delayed reboots and reminders.
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Why Your Docker Container Ignores Ctrl+C
PID 1 doesn't receive signals by default. Learn why Ctrl+C fails in containers and fix it with tini or exec form CMD.
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Optimize Ubuntu Logs: btmp Log Rotation
btmp logs failed logins and grows forever on internet-facing servers. Set up logrotate to keep it under control before your disk fills up.
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Finding the PID of a Process Using a Specific Port in Linux
Something's squatting on port 8080 and you need to know what. ss, lsof, and fuser one-liners to find and kill the culprit fast.
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Differences Between nohup, disown, and & in Linux
nohup, disown, and & all keep processes running after logout — but they work differently. Here's which one to reach for and why.
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the lost+found Directory in Linux
What is lost+found and why does it exist? fsck puts recovered file fragments there after a crash — and no, you can't delete it.