RHCSA
862 incident response problems that help with RHCSA prep.
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All problems (862)
LINUX-154A network namespace teardown removes the veth peer too early, and a lingering process keeps writing logs to a path that no longer exists in the host namespaceThe main workload exited, but one helper kept running and exposed cleanup order assumptions.LinuxAdvanced17 minProLINUX-147A readonly bind mount protects the app config, but a late remount from a maintenance script flips the parent mount writable againDefense in depth existed, yet a broader filesystem action implicitly changed the narrower protection.LinuxAdvanced17 minProLINUX-336A restore repopulates ACLs correctly while default inheritance and newly created subpaths drift immediately from the recovered design during a failover rehearsalThe present state is right and the future state starts drifting with the next write. Normal traffic masked the issue until the standby or alternate path became active under rehearsal conditions.LinuxAdvanced17 minProLINUX-369A storage cleanup frees file blocks while an abandoned overlay or container layer still holds the inode pressure that triggered the incident during a staged decommissionCapacity charts improve and the inode shortage remains. The service still works through the primary path, but one dependency only fails when the old component is finally drained away.LinuxAdvanced17 minProLINUX-135A suspended virtual machine resumes with massive clock skew, but chrony makestep settings never allow the correction window to triggerTime drift is obvious, yet the recovery policy does not consider this magnitude eligible for immediate correction anymore.LinuxAdvanced17 minProLINUX-1282A systemd mount unit appears active but applications still failAn app suddenly loses write ability on a mounted path even though the mount unit and path both look present in routine checks.LinuxAdvanced17 minProLINUX-1269A systemd service flaps even though the binary is healthyA newly wrapped service appears stable by hand and immediately enters restart loops once managed by systemd.LinuxAdvanced17 minProLINUX-357A systemd service restarts correctly while its watchdog still points at a pid file recreated by a helper process in a different mount namespace during a staged decommissionAvailability checks pass in one namespace and fail in another. The service still works through the primary path, but one dependency only fails when the old component is finally drained away.LinuxAdvanced17 minProLINUX-258A thin snapshot is mounted read-only while one housekeeping timer still tries to trim and purge inside it during a failover rehearsalThe maintenance timer keeps running against a snapshot that no longer accepts the same write behavior. Normal traffic masked the issue until the standby or alternate path became active under rehearsal conditions.LinuxIntermediate17 minProLINUX-511An application writes Unicode filenames correctlyAn application writes Unicode filenames correctly focuses on linux-performance-and-observability and asks the reader to isolate Rollout Stuck. 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 빨리 좁힐 수 있습니다.LinuxIntermediate17 minProLINUX-157An mdadm write-intent bitmap survives the array move, but sector size assumptions changed and recovery performance collapses on the new hostThe array is valid, yet one metadata optimization no longer matches the hardware characteristics.LinuxAdvanced17 minProLINUX-122An nftables set restores from disk without the interval flag and a whole CIDR block filter collapses into discrete entriesThe firewall loads successfully, but the restored semantics no longer represent the intended range-based policy.LinuxAdvanced17 minProLINUX-125An rsync inplace copy lands on an XFS reflink-based volume and backup verification later finds silently shared extentsThe transfer finished, but the data isolation assumption behind the backup strategy no longer holds.LinuxAdvanced17 minProLINUX-1294An rsync mirror looks complete but ACLs are wrong on the targetA migration completes cleanly and later only some files behave as though permissions were incompletely restored.LinuxAdvanced17 minProLINUX-381An SELinux file context restore fixes the target path while a transient tmpfiles rule recreates it at boot with the wrong type again during a staged decommissionManual recovery works and the next boot silently undoes it. The service still works through the primary path, but one dependency only fails when the old component is finally drained away.LinuxAdvanced17 minProLINUX-118cgroup v2 memory.high throttles the workers and the service looks slow instead of obviously brokenLatency climbs without hard OOM events because the workload is being pressured by the soft limit long before memory.max is reached.LinuxAdvanced17 minProLINUX-103Chrony sources are healthy but orphan mode keeps a node serving stale time after the upstream recoversNTP peers look reachable, yet one host continues advertising an old authority state because the failover mode never relinquished control cleanly.LinuxAdvanced17 minProLINUX-1257Disk usage never drops after log cleanupAn incident response clears huge logs and sees no disk relief even though the files appear gone from the directory listing.LinuxAdvanced17 minProLINUX-1277SELinux blocks a restored web tree even though file modes look correctA site migration or restore appears complete and the web server still returns permission errors on restored files.LinuxAdvanced17 minProLINUX-151SELinux module priority causes a vendor policy package to override the local custom allow rule after patchingThe local fix still exists on disk, but load order changed which rule wins at runtime.LinuxAdvanced17 minPro