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Overview

Pools are the logical containers for stored data. Each pool has a defined data protection policy (replication or erasure coding), a device class mapping, and a PG count. Creating pools correctly at the outset avoids disruptive reconfiguration later.
Administrator Access Required — This operation requires the admin role. Contact your Xloud administrator if you do not have sufficient permissions.
Prerequisites
  • Administrator credentials with the admin role
  • SSH access to a cluster management node
  • CRUSH map configured with appropriate device class rules (see CRUSH Maps)

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Creating Pools

Create the pool

Create a replicated pool
ceph osd pool create <POOL_NAME> <PG_COUNT> <PG_COUNT> replicated
For most pools, set PG count to 128 initially — the PG autoscaler will adjust automatically as data volume grows.

Set replication factor

Set replication size (factor)
ceph osd pool set <POOL_NAME> size 3
ceph osd pool set <POOL_NAME> min_size 2
size is the total number of copies. min_size is the minimum needed to serve I/O (allows degraded operation with 2 copies during OSD failure recovery).

Assign a CRUSH rule

Associate the pool with a CRUSH rule that targets the correct device class:
Set CRUSH rule on pool
ceph osd pool set <POOL_NAME> crush_rule replicated_rule_ssd
Use ceph osd crush rule ls to list available rules.

Enable pool application

Tag the pool with its application type so the cluster knows how to manage it:
Enable RBD (block storage) on pool
ceph osd pool application enable <POOL_NAME> rbd
Valid application types: rbd (block), rgw (object), cephfs (file).
Pool appears in ceph osd pool ls detail with correct application and replication settings.

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Managing Existing Pools

List all pools with details
ceph osd pool ls detail
Show pool statistics
ceph df detail
Show specific pool configuration
ceph osd pool get <POOL_NAME> all

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Pool Configuration Reference

ParameterCommandNotes
Replication sizeceph osd pool set <pool> size <n>Number of copies
Minimum sizeceph osd pool set <pool> min_size <n>Min copies for I/O
CRUSH ruleceph osd pool set <pool> crush_rule <rule>Device class routing
PG autoscaleceph osd pool set <pool> pg_autoscale_mode onAutomatic PG sizing
Compressionceph osd pool set <pool> compression_mode aggressiveInline compression
Quotasceph osd pool set-quota <pool> max_bytes <bytes>Capacity limit

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Next Steps

CRUSH Maps

Configure failure domains and device class rules for pool placement

Storage Tiers

Map pools to Cinder volume types for multi-tier storage

Capacity Planning

Monitor pool utilization and plan expansion

Troubleshooting

Diagnose pool-related issues — PG warnings, capacity alerts