> ## Documentation Index
> Fetch the complete documentation index at: https://docs.xloud.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Pool Management

> Create and configure replicated and erasure-coded storage pools, set application types, and manage pool settings in XSDS.

## 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.

<Warning>
  **Administrator Access Required** — This operation requires the `admin` role. Contact your
  Xloud administrator if you do not have sufficient permissions.
</Warning>

<Note>
  **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](/services/sds/admin-guide/crush-maps))
</Note>

***

## Creating Pools

<Tabs>
  <Tab title="Replicated Pool" icon="copy">
    <Steps titleSize="h3">
      <Step title="Create the pool" icon="plus">
        ```bash title="Create a replicated pool" theme={null}
        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.
      </Step>

      <Step title="Set replication factor" icon="copy">
        ```bash title="Set replication size (factor)" theme={null}
        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).
      </Step>

      <Step title="Assign a CRUSH rule" icon="map">
        Associate the pool with a CRUSH rule that targets the correct device class:

        ```bash title="Set CRUSH rule on pool" theme={null}
        ceph osd pool set <POOL_NAME> crush_rule replicated_rule_ssd
        ```

        Use `ceph osd crush rule ls` to list available rules.
      </Step>

      <Step title="Enable pool application" icon="check">
        Tag the pool with its application type so the cluster knows how to manage it:

        ```bash title="Enable RBD (block storage) on pool" theme={null}
        ceph osd pool application enable <POOL_NAME> rbd
        ```

        Valid application types: `rbd` (block), `rgw` (object), `cephfs` (file).

        <Check>Pool appears in `ceph osd pool ls detail` with correct application and replication settings.</Check>
      </Step>
    </Steps>
  </Tab>

  <Tab title="Erasure-Coded Pool" icon="code">
    <Steps titleSize="h3">
      <Step title="Create an erasure code profile" icon="settings">
        ```bash title="Create erasure code profile (4+2 on HDD)" theme={null}
        ceph osd erasure-code-profile set ec-4-2 \
          k=4 m=2 crush-device-class=hdd
        ```

        ```bash title="Create erasure code profile (8+3 for large archives)" theme={null}
        ceph osd erasure-code-profile set ec-8-3 \
          k=8 m=3 crush-device-class=hdd
        ```
      </Step>

      <Step title="Create the pool using the profile" icon="plus">
        ```bash title="Create erasure-coded pool" theme={null}
        ceph osd pool create <POOL_NAME> erasure ec-4-2
        ```
      </Step>

      <Step title="Enable pool application" icon="check">
        ```bash title="Enable RGW (object storage) on EC pool" theme={null}
        ceph osd pool application enable <POOL_NAME> rgw
        ```

        <Note>
          Erasure-coded pools cannot be used directly for block storage (RBD) without
          a replicated overlay pool. Use erasure coding primarily for object storage
          and large object archives.
        </Note>

        <Check>Pool appears in `ceph osd pool ls detail` with erasure code profile listed.</Check>
      </Step>
    </Steps>
  </Tab>
</Tabs>

***

## Managing Existing Pools

<Tabs>
  <Tab title="Inspect Pools" icon="search">
    ```bash title="List all pools with details" theme={null}
    ceph osd pool ls detail
    ```

    ```bash title="Show pool statistics" theme={null}
    ceph df detail
    ```

    ```bash title="Show specific pool configuration" theme={null}
    ceph osd pool get <POOL_NAME> all
    ```
  </Tab>

  <Tab title="Modify Pools" icon="settings">
    ```bash title="Enable PG autoscaling on a pool" theme={null}
    ceph osd pool set <POOL_NAME> pg_autoscale_mode on
    ```

    ```bash title="Set compression on a pool" theme={null}
    ceph osd pool set <POOL_NAME> compression_mode aggressive
    ceph osd pool set <POOL_NAME> compression_algorithm lz4
    ```

    ```bash title="Rename a pool" theme={null}
    ceph osd pool rename <OLD_NAME> <NEW_NAME>
    ```
  </Tab>

  <Tab title="Delete a Pool" icon="trash">
    <Danger>
      Pool deletion is irreversible and permanently destroys all data stored in the
      pool. Confirm with the requesting team that all data has been migrated or is
      no longer needed before proceeding.
    </Danger>

    ```bash title="Enable pool deletion (required safety flag)" theme={null}
    ceph config set mon mon_allow_pool_delete true
    ```

    ```bash title="Delete pool (requires double confirmation)" theme={null}
    ceph osd pool delete <POOL_NAME> <POOL_NAME> \
      --yes-i-really-really-mean-it
    ```

    ```bash title="Re-disable pool deletion after use" theme={null}
    ceph config set mon mon_allow_pool_delete false
    ```
  </Tab>
</Tabs>

***

## Pool Configuration Reference

| Parameter        | Command                                                | Notes                |
| ---------------- | ------------------------------------------------------ | -------------------- |
| Replication size | `ceph osd pool set <pool> size <n>`                    | Number of copies     |
| Minimum size     | `ceph osd pool set <pool> min_size <n>`                | Min copies for I/O   |
| CRUSH rule       | `ceph osd pool set <pool> crush_rule <rule>`           | Device class routing |
| PG autoscale     | `ceph osd pool set <pool> pg_autoscale_mode on`        | Automatic PG sizing  |
| Compression      | `ceph osd pool set <pool> compression_mode aggressive` | Inline compression   |
| Quotas           | `ceph osd pool set-quota <pool> max_bytes <bytes>`     | Capacity limit       |

***

## Next Steps

<CardGroup cols={2}>
  <Card title="CRUSH Maps" href="/services/sds/admin-guide/crush-maps" color="#197560">
    Configure failure domains and device class rules for pool placement
  </Card>

  <Card title="Storage Tiers" href="/services/sds/admin-guide/storage-tiers" color="#197560">
    Map pools to Cinder volume types for multi-tier storage
  </Card>

  <Card title="Capacity Planning" href="/services/sds/admin-guide/capacity-planning" color="#197560">
    Monitor pool utilization and plan expansion
  </Card>

  <Card title="Troubleshooting" href="/services/sds/admin-guide/troubleshooting" color="#197560">
    Diagnose pool-related issues — PG warnings, capacity alerts
  </Card>
</CardGroup>