RHCSA
862 incident response problems that help with RHCSA prep.
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All problems (862)
LINUX-1207Systemd service fails only in unit contextAn operator validates a script interactively, then deploys it under systemd from a hardened mount and it stops working.LinuxIntermediate16 minProLINUX-1243A backup job writes the right files but restore later failsA file restore seems fine until an application or service account on the new host cannot read the restored data.LinuxIntermediate17 minProLINUX-1253A backup restore looks complete but the application still failsA restore succeeds on a new host and later the application cannot read or write the recovered data despite the files being present.LinuxIntermediate17 minProLINUX-1262A cloned VM mounts the wrong disk after rebootLinux incident scenario used for structured troubleshooting practice.LinuxIntermediate17 minProLINUX-288A direct firewall fix survives until reboot while NetworkManager restores a different zone binding for the new uplink profile during a failover rehearsalThe rule exists and the interface moved to a different policy domain underneath it. Normal traffic masked the issue until the standby or alternate path became active under rehearsal conditions.LinuxIntermediate17 minProLINUX-228A journal vacuum policy frees one filesystem while a coredump directory on another keeps growing unchecked during a failover rehearsalLogs look healthy and the diagnostic path that really consumes space was outside the cleanup policy. Normal traffic masked the issue until the standby or alternate path became active under rehearsal conditions.LinuxIntermediate17 minProLINUX-312A journald retention policy frees local logs while remote-forward queue spillover still fills the spool filesystem during collector outages during a failover rehearsalLog retention seems tuned and the buffering path for remote resilience is where storage actually disappears. Normal traffic masked the issue until the standby or alternate path became active under rehearsal conditions.LinuxIntermediate17 minProLINUX-1235A periodic backup mounts storage correctly but writes into the local mountpointA backup job continues to write to its usual path even after the remote mount failed or detached earlier in the day.LinuxIntermediate17 minProLINUX-1248A restore succeeds but the application still failsA backup restore seems complete until the service on the new host cannot read or write the recovered data.LinuxIntermediate17 minProLINUX-1264A systemd service flaps even though the binary is healthyLinux incident scenario used for structured troubleshooting practice.LinuxIntermediate17 minProLINUX-1209Cron script succeeds manually but fails overnightA maintenance job can resolve an internal host manually but fails overnight when cron runs it non-interactively.LinuxIntermediate17 minProLINUX-1205Journal logs show the symptom but the real failure happened earlier in a rotated boot that operators no longer inspectCurrent logs only show the aftermath because the meaningful startup error lived in the previous boot or earlier rotation window that no one checked.LinuxIntermediate17 minProLINUX-1218Log cleanup looks correct but an older wildcard deletes the current release symlink target during rotationA housekeeping rule appears to remove only old paths, yet one broad wildcard still matches the live release target after the symlink rotates.LinuxIntermediate17 minProLINUX-1221Logrotate rotates the file but disk usage stays highA log file rotates and disappears from the directory listing, but the filesystem remains full.LinuxIntermediate17 minProLINUX-1211Logrotate uses copytruncate and still loses linesA busy log file rotates frequently and operators later discover missing lines around each window.LinuxIntermediate17 minProLINUX-1195Package update job fails only under automationAn operator can update packages interactively, but scheduled or automated runs fail because the proxy variables were never made available outside the shell profile.LinuxIntermediate17 minProLINUX-1187Time skew makes valid certificates look expired on only one serverTLS handshakes fail on one node because system time drift makes otherwise valid certificates appear expired or not yet valid.LinuxIntermediate17 minProLINUX-469A firewalld rich rule is correct (Timeouts and Latency)A firewalld rich rule is correct (Timeouts and Latency) focuses on linux-network-and-firewall and asks the reader to isolate Timeouts and Latency. 실무에서는 linux-network-and-firewall 문제를 볼 때 서비스 로그만 보지 말고 inode, 파일시스템 여유, 포트 점유, systemd 상태, 최근 패키지 변경까지 같이 확인해야 원인을 빨리 좁힐 수 있습니다.LinuxIntermediate18 minProLINUX-495A log rotation policy is correct (Resource Exhaustion)A log rotation policy is correct (Resource Exhaustion) focuses on linux-performance-and-observability and asks the reader to isolate Resource Exhaustion. 실무에서는 linux-performance-and-observability 문제를 볼 때 서비스 로그만 보지 말고 inode, 파일시스템 여유, 포트 점유, systemd 상태, 최근 패키지 변경까지 같이 확인해야 원인을...LinuxIntermediate18 minProLINUX-1200Cleanup script empties the wrong directoryA cleanup pattern from community posts worked for months. After a deployment changed one symlink target, the same cleanup logic begins operating on the wrong path.LinuxIntermediate18 minPro