OAOpeyemi Adenijiincodewithniji.hashnode.dev·7h ago · 12 min readHow I audit 50 servers with one Ansible commandImagine you run 50 servers and you need an answer to one question: which of them need attention right now? The manual way is to SSH into each one, run df -h, free -m, ps and ss -ltn, and copy the resu03A
HHelloCroninhellocron.hashnode.dev·4h ago · 9 min readWhere are cron logs? Finding cron output on Ubuntu, Debian, RHEL, Alpine and in containers"Where are cron logs?" is really two questions, and most of the confusion around cron comes from mixing them up. The first is: did cron start my job at all? That is answered by the cron daemon's log, 00
PGPro Gineousinprogineous.hashnode.dev·11h ago · 8 min readWhy WordPress Missed Your Scheduled Post (and How to Fix WP-Cron)You scheduled a post for 11:00, closed the laptop, and came back after lunch to find it still sitting in the Posts list with a red "Missed schedule" label where the publish date should be. Nothing cra00
AIArtifex Ignotvsinartifexignotvs.hashnode.dev·11h ago · 5 min readThree seconds apart: testing the clock assumption behind an incident findingA successful login record is timestamped 09:09:12. A process-execution record is timestamped 09:09:15. The recorded timestamps are three seconds apart. Does that establish that the process followed th00
UKUk Kintech-learning-sachin.hashnode.dev·12h ago · 10 min readDiagnosing Linux Disk Pressure When df and du DisagreeDisk-space alerts are among the most common issues on a Linux server. An application may stop writing logs, a package installation may fail, or a database may complain that it cannot create a temporar00
JOJoseph O'Shaughnessyinjosephoshaughnessy.hashnode.dev·1d ago · 12 min readDiagnosing a Failed TCP Handshake in WiresharkWhen someone says "the application is down", the quickest way to settle whether it's the network is to look at the TCP handshake. If the three-way handshake never completes, the application never gets00
PAPaul Adeoyeinpaulking.hashnode.dev·20h ago · 13 min readBash Scripting and Linux Server Automation Linux administration often involves repeating the same operations: checking application health, validating configuration files, organizing backups, collecting system information, and preparing routine00
PAPaul Adeoyeinpaulking.hashnode.dev·21h ago · 14 min readLinux Networking, SSH, Logs, and TroubleshootingA Linux server can be running normally and still be unreachable. An application may be healthy locally but inaccessible from another machine. A domain name may resolve to the wrong address, a service 00
JOJoseph O'Shaughnessyinjosephoshaughnessy.hashnode.dev·23h ago · 12 min readFinding an MTU Black Hole with ping, tcpdump and WiresharkYou can SSH to the server. The login page loads. Ping works. But the moment someone downloads a large file or opens a big report, it just sits there, and eventually times out. Everyone swears the netw00
PAPaul Adeoyeinpaulking.hashnode.dev·1d ago · 13 min readLinux Processes, Services, Packages, and System AdministrationA Linux server can run dozens or even hundreds of processes at the same time. Web servers, application runtimes, databases, monitoring agents, scheduled jobs, and system components all depend on those00
