---
title: Ceph Cluster
category: systems
tags: [ceph, storage, rbd, ec-pool, osd]
created: "2026-07-24"
modified: "2026-09-26"
---

# Ceph Cluster

## Overview
- **Cluster ID**: 204c8171-e0b1-4f40-9de2-a7cfe4ef68d9
- **Health**: HEALTH_WARN — "Monitors are configured to allow creation of insecure key types" (cosmetic, CVE-2025-30156 fixed)
- **Version**: 20.2.4 (tentacle) — all 17 OSDs
- **Nodes**: 8 Proxmox hosts (proxmox2 removed from CRUSH), 4 MONs (proxmox5, proxmox4, ms-a2-1, n5pro), MGR on n5pro (standbys: px5/6/7/a2-1)
- **OSDs**: 17 (10 HDD, 7 SSD), all up/in
- **Capacity**: ~33 TiB total, 9.0 TiB used, 24 TiB avail
- **Pools**: 13 pools, 533 PGs (532 active+clean, 1 scrubbing)

## OSD Layout

| OSD | Class | Size | Host | Reweight | Notes |
|-----|-------|------|------|----------|-------|
| 1 | hdd | 3.7 TiB | n5pro | 1.0 | |
| 2 | ssd | 1.8 TiB | ubuntu | 1.0 | Moved to ubuntu host |
| 3 | ssd | 233 GB | proxmox4 | 1.0 | |
| 4 | ssd | 227 GB | proxmox3 | 0.30 | Small, reweighted down |
| 5 | ssd | 150 GB | proxmox5 | 0.30 | Small, reweighted down |
| 6 | hdd | 3.6 TiB | n5pro | 1.0 | |
| 7 | hdd | 931 GB | proxmox7 | 0.95 | |
| 8 | hdd | 3.6 TiB | ubuntu | 1.0 | |
| 9 | ssd | 1.9 TiB | n5pro | 1.0 | |
| 10 | hdd | 931 GB | proxmox6 | 0.95 | |
| 11 | hdd | 2.8 TiB | n5pro | 1.0 | |
| 12 | ssd | 1.9 TiB | n5pro | 1.0 | |
| 13 | ssd | 1.8 TiB | ms-a2-1 | 0.95 | |
| 14 | ssd | 1.8 TiB | ms-a2-2 | 0.95 | |
| 15 | ssd | 1.8 TiB | ubuntu | 1.0 | New |
| 17 | hdd | 3.6 TiB | ubuntu | 1.0 | New |
| 18 | hdd | 3.6 TiB | ubuntu | 1.0 | New |

> OSDs 0+2 (old proxmox2) destroyed 2026-07-25. osd.2 reassigned to ubuntu host as new SSD.
> OSDs 15, 17, 18 added since last wiki update (ubuntu host expanded).

## Pools

| Pool | Name | Type | Size | Min | CRUSH Rule | PGs | Notes |
|------|------|------|------|-----|------------|-----|-------|
| 1 | cephfs_data | replicated | 3 | 2 | 0 (any) | 32 | autoscale off |
| 2 | cephfs_metadata | replicated | 3 | 2 | 2 (ssd) | 32 | autoscale off |
| 3 | vm_disks | replicated | 3 | 2 | 2 (ssd) | 128 | autoscale on |
| 4 | .mgr | replicated | 3 | 2 | 2 (ssd) | 1 | |
| 5 | rbd | replicated | 3 | 2 | 1 (hdd) | 32 | autoscale on |
| 6 | hdd_disk | replicated | 3 | 2 | 1 (hdd) | 112 | nopgchange=true |
| 7 | tm_disks | replicated | 2 | 2 | 1 (hdd) | 128 | target_size 2TiB |
| 8 | media_ec | erasure 4+1 | 5 | 4 | 3 (hdd, osd-level) | 128 | ec_overwrites |
| 9 | media_meta | replicated | 3 | 2 | 0 (any) | 32 | |
| 10 | .rgw.root | replicated | 3 | 2 | 0 (any) | 1 | |

## CRUSH Rules
- **Rule 0** (replicated_rule): default root, host-level placement
- **Rule 1** (replicated_hdd): default~hdd, host-level placement
- **Rule 2** (replicated_ssd): default~ssd, host-level placement
- **Rule 3** (media_ec): default~hdd, OSD-level placement (choose_indep)

## Known Issues

### HEALTH_WARN: Insecure Key Types (2026-09-26)
Monitors allow insecure key types. Cosmetic warning — CVE-2025-30156 already fixed in 20.2.4.
Fix: `ceph config set mon mon_allow_insecure_global_id_reclaim false` (if not already set).

### Small SSDs causing reweightdown
osd.4 (227GB, proxmox3) and osd.5 (150GB, proxmox5) reweighted to 0.30 — too small for meaningful capacity.
Consider removing from CRUSH or replacing with larger drives.

### worker-04 (VM 139) NotReady in K8s
Node offline — not a Ceph issue but affects Ceph CSI attachments.

## Access
- SSH to Proxmox hosts: `ssh -i ~/.ssh/id_ed25519_proxmox root@10.0.20.50`
- Ceph commands: `ceph status`, `ceph osd tree`, `ceph pg dump pgs`
- Mon nodes: proxmox5 (leader), proxmox4, ms-a2-1, n5pro
- Mgr: n5pro (active)

## Related Skills
- `ceph-cluster-administration` (devops)

## Related
- [[systems/proxmox-cluster]]
- [[systems/rke2-kubernetes]] (Ceph CSI)