Overview of Telemetry Data Categories

Ceph telemetry collects data in distinct channels. Each channel covers a specific category of information. Before opting in, you can preview each channel's payload to understand what is shared.

Preview all telemetry data:

ceph telemetry show

Preview a specific channel:

ceph telemetry show basic
ceph telemetry show crash
ceph telemetry show device

Basic Channel - What Is Collected

The basic channel includes anonymized cluster topology and configuration:

• Ceph version and release
• Number of monitors, OSDs, and MDSs
• OSD and pool configurations (without hostnames or IPs)
• Cluster ID (a UUID, not tied to any personally identifiable information)
• Enabled features and flags
• CRUSH map structure (anonymized)

Example of basic telemetry output:

ceph telemetry show basic | python3 -m json.tool | head -50

Crash Channel - What Is Collected

The crash channel sends anonymized crash reports:

• Crash timestamp and Ceph version
• Stack trace from the crash
• Daemon type (OSD, MON, MGR) that crashed
• No hostname, IP address, or cluster-specific data

View current crash reports:

ceph crash ls
ceph crash info <crash-id>

Device Channel - What Is Collected

The device channel shares SMART health data predictions:

• Drive model and firmware version
• SMART attributes used for health scoring
• Predicted failure probability
• No serial numbers or host associations

Check device health data:

ceph device ls
ceph device info <device-id>

What Is NOT Collected

Ceph telemetry explicitly excludes:

• Hostnames and IP addresses
• Object names, bucket names, or user data
• Ceph user account names
• RGW, CephFS, or RBD client data
• Any data stored in the cluster

Inspecting the Full Telemetry Report

Generate the complete JSON report that would be sent:

ceph telemetry show --format json > /tmp/telemetry-preview.json
cat /tmp/telemetry-preview.json | python3 -m json.tool | less

Count items by section:

ceph telemetry show --format json | python3 -c "
import sys, json
d = json.load(sys.stdin)
for k, v in d.items():
    print(f'{k}: {type(v).__name__}')
"

Rook Toolbox Commands

Access telemetry inspection from the toolbox:

kubectl -n rook-ceph exec -it deploy/rook-ceph-tools -- \
  ceph telemetry show basic

Summary

Ceph telemetry collects only anonymized cluster structure and health data - no user data, hostnames, or personally identifiable information is ever sent. The basic, crash, and device channels each cover distinct aspects of cluster metadata. Running ceph telemetry show before opting in lets you verify the payload is acceptable for your organization's data policies.