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← All break/fix scenarios in Ceph

advancedceph-bluestore-db~25 min

BlueStore integrity check fails - the OSD is corrupt

Reported symptoms

  • ●ceph-bluestore-tool fsck reports checksum errors on an OSD
  • ●The OSD repeatedly crashes on startup
  • ●The OSD refuses to start with bluestore error opening

Evidence

  • · ceph-bluestore-tool fsck --path /var/lib/ceph/osd/ceph-N shows the errors
  • · journalctl -u ceph-osd@N shows bluefs errors
  • · ceph osd metadata N shows the OSD config
Diagnosis and resolutionclick to reveal

Root cause

BlueStore on the OSD has integrity failures. Likely a disk device failure or a kernel bug. The OSD cannot recover.

Remediation

Mark the OSD out; wait for backfill; replace the disk; recreate the OSD on a new device.

Verification

ceph -s reports HEALTH_OK; the replaced disk is up; affected PGs return to active+clean.

Prevention

Monitor SMART / NVMe health; alert on disk errors; never disable the integrity check.

Architecture

The student examines the broken architecture diagram and identifies the responsible component. The cluster is running Ceph Tentacle (20.2.x); the incident is one a production operator must diagnose from the evidence presented.

Symptoms

  • ceph-bluestore-tool fsck reports checksum errors on an OSD
  • The OSD repeatedly crashes on startup
  • The OSD refuses to start with bluestore error opening

Evidence

  • ceph-bluestore-tool fsck —path /var/lib/ceph/osd/ceph-N shows the errors
  • journalctl -u ceph-osd@N shows bluefs errors
  • ceph osd metadata N shows the OSD config

Student investigation

The student follows the methodology: define the symptom, determine the impact, gather evidence, identify the component, form a hypothesis, test safely, restore, validate.

Progressive hints

  • Hint 1: check the cluster state with ceph -s first.
  • Hint 2: read ceph health detail and identify the affected PGs / OSDs / daemons.
  • Hint 3: use ceph osd tree, ceph pg dump, or ceph mds stat as the next-level diagnostic.
  • Hint 4: the root cause is documented in the frontmatter root_cause field.

Validation

The student runs the verification steps and confirms the symptom cleared.

Root cause

See the frontmatter root_cause field.

Remediation

Apply the fix from the frontmatter remediation field.

Prevention

Apply the prevention measures from the frontmatter prevention field.