Storage Tiers

Overview

Multi-tier storage routes different workload classes to appropriate device media through volume types in the block storage service and pool configurations in nxtStore. Tier configuration is managed through nxtDeploy’s Storage Tiers panel, which auto-generates the required pool, CRUSH rule, and block storage backend configuration.

Administrator Access Required — This operation requires the admin role. Contact your NxtSight administrator if you do not have sufficient permissions.

nxtDeploy GUI — Storage tier detection, CRUSH rule creation, and pool configuration can be performed through the nxtStore Storage interface under the Storage Tiers tab. Click Detect Tiers to automatically discover device classes. No manual file editing required.

Prerequisites

Administrator credentials with the admin role
Device class CRUSH rules created for each tier (see CRUSH Maps)
Access to nxtDeploy (https://connect.<your-domain>)

Tier Overview

Tier	Device Class	Pool	Volume Type	Use Case
NVMe	`nvme`	`volumes-nvme`	`ceph-nvme`	Databases, OLTP, latency-critical
SSD	`ssd`	`volumes` (default)	`ceph-ssd`	General-purpose, web, application
HDD	`hdd`	`volumes-hdd`	`ceph-hdd`	Backup, archive, big data

Configuring Tiers via nxtDeploy

Open Storage Tiers panel

Navigate to nxtDeploy → Configuration → Storage Tiers.The panel displays detected device classes in the cluster and lets you define which tiers to expose as volume types.

Add a new tier

Click Add Tier and configure:

Field	Description
Tier Name	Display name (e.g., `NVMe Performance`)
Device Class	Physical media class: `nvme`, `ssd`, or `hdd`
Pool Name	Name for the storage pool (e.g., `volumes-nvme`)
Volume Type	Cinder volume type name exposed to users (e.g., `ceph-nvme`)
Default	Whether this tier is the default for new volumes without an explicit type

Set the fastest available tier as the default volume type. Users who don’t specify a type explicitly receive the best performance tier.

Apply configuration

Click Apply. nxtDeploy automatically:

Creates the pool with the correct CRUSH rule for the device class
Registers the Cinder backend pointing to the new pool
Creates the volume type with appropriate extra specs
Updates the _50_ceph_tiers.yml configuration file

New volume type appears in openstack volume type list and is available to tenants.

Manual Tier Configuration

For environments where nxtDeploy is not managing tier configuration, configure tiers manually.

Create Pool and Rule
Register Cinder Backend

Create CRUSH rule for NVMe

ceph osd crush rule create-replicated \
  replicated_rule_nvme default host nvme

Create NVMe-backed pool

ceph osd pool create volumes-nvme 128 128 replicated
ceph osd pool set volumes-nvme size 3
ceph osd pool set volumes-nvme min_size 2
ceph osd pool set volumes-nvme crush_rule replicated_rule_nvme
ceph osd pool application enable volumes-nvme rbd

Add the new backend to your Cinder configuration (managed by nxtDeploy via globals.d/_50_ceph_tiers.yml):

/etc/nxtVirt/globals.d/_50_ceph_tiers.yml

cinder_ceph_backends:
  - name: ceph-ssd
    pool: volumes
    device_class: ssd
  - name: ceph-nvme
    pool: volumes-nvme
    device_class: nvme
  - name: rbd-1
    pool: volumes

ceph_default_volume_type: ceph-nvme

Then deploy the block storage configuration:

Deploy Cinder configuration

nxtVirt-ansible deploy -t cinder

Verifying Tier Configuration

Check Volume Types
Test Volume Creation

List all volume types

openstack volume type list

Show volume type extra specs

openstack volume type show ceph-nvme -c extra_specs

The volume_backend_name extra spec should match the Cinder backend name.

Create a test volume on the NVMe tier

openstack volume create \
  --size 10 \
  --type ceph-nvme \
  test-nvme-volume

Verify it reaches AVAILABLE status

openstack volume show test-nvme-volume -c status

Clean up test volume

openstack volume delete test-nvme-volume

Volume reaches available status — the tier is correctly configured end-to-end.

Next Steps

CRUSH Maps

Configure device class rules that route each tier to the correct physical media

Pool Management

Manage the pools backing each storage tier

Capacity Planning

Monitor per-tier utilization and plan expansion

Block Storage — Volume Types

Advanced Cinder volume type configuration for QoS and backend selection

Core Services

Other Services

Storage Tiers

Overview

Tier Overview

Configuring Tiers via nxtDeploy

Open Storage Tiers panel

Add a new tier

Apply configuration

Manual Tier Configuration

Verifying Tier Configuration

Next Steps

CRUSH Maps

Pool Management

Capacity Planning

Block Storage — Volume Types

​Overview

​Tier Overview

​Configuring Tiers via nxtDeploy

Open Storage Tiers panel

Add a new tier

Apply configuration

​Manual Tier Configuration

​Verifying Tier Configuration

​Next Steps

CRUSH Maps

Pool Management

Capacity Planning

Block Storage — Volume Types

Overview

Tier Overview

Configuring Tiers via nxtDeploy

Manual Tier Configuration

Verifying Tier Configuration

Next Steps