Storage Subsystem Guides on Cozystack

Preparing Disks for LINSTOR Storage Pools

Mon, 01 Jan 0001 00:00:00 +0000

This guide explains how to prepare physical disks for use with LINSTOR when they contain old metadata that prevents automatic detection.

Problem Description

When setting up storage on new or repurposed nodes, physical disks may contain remnants from previous installations:

RAID superblocks
Partition tables
LVM signatures
Filesystem metadata

This old metadata prevents LINSTOR from detecting disks as available storage.

Symptoms

linstor physical-storage list shows empty output or missing disks
Disks appear with unexpected filesystem types (e.g., linux_raid_member)
Storage pools only show DfltDisklessStorPool without actual storage

Diagnostics

Set up LINSTOR alias

For easier access to LINSTOR commands, set up an alias:

Configuring a Dedicated Network for LINSTOR

Mon, 01 Jan 0001 00:00:00 +0000

This guide explains how to improve storage reliability and performance by redirecting LINSTOR replication traffic to a dedicated network interface.

Introduction

The Cozystack platform is built to support high-availability (HA) workloads, which means the system must continue operating even if one or more nodes go offline. Kubernetes handles this well for stateless workloads. However, stateful workloads, such as file storage or virtual machine disks, require a reliable storage backend.

When you choose the replicated storage class for a PersistentVolumeClaim (PVC) or DataVolume, LINSTOR creates multiple synchronous replicas of the data across different nodes. This ensures that if a node fails (due to a power outage, hardware issue, etc.), the data remains instantly available on another node.

Configuring DRBD Resync Controller in LINSTOR

Mon, 01 Jan 0001 00:00:00 +0000

Cozystack administrators can adjust DRBD synchronization performance by setting tuning parameters for the LINSTOR Controller.

This allows you to optimize the speed of resynchronization without overloading the replication network or storage backend.

For detailed explanations of all available parameters and tuning recommendations, please refer to the official LINBIT guide: Tuning the DRBD Resync Controller.

For a multi-datacenter setup, also read the Multi-DC DRBD configuration.

Recommended Settings for 10G Networks

We consider the following values to be optimal for clusters connected with a 10-Gigabit network:

Using NFS shares with Cozystack

Mon, 01 Jan 0001 00:00:00 +0000

Enable NFS driver

Add bundle-enable: nfs-driver to your Cozystack configuration:

bundle-enable: nfs-driver

Wait a minute for the platform chart to reconcile, then verify the HelmRelease has been created:

kubectl get helmrelease --namespace cozy-nfs-driver nfs-driver

apt install nfs-server
mkdir /data
chmod 777 /data
echo '/data *(rw,sync,no_subtree_check)' >> /etc/exports
exportfs -a

Configure connection

---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
 name: nfs
provisioner: nfs.csi.k8s.io
parameters:
 server: 10.244.57.210
 share: /data
reclaimPolicy: Delete
volumeBindingMode: Immediate
allowVolumeExpansion: true
mountOptions:
 - nfsvers=4.1

Order volume

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
 name: task-pv-claim
spec:
 storageClassName: nfs
 accessModes:
 - ReadWriteMany
 resources:
 requests:
 storage: 3Gi

Creating Encrypted Storage on LINSTOR

Mon, 01 Jan 0001 00:00:00 +0000

Cozystack administrators can enable encrypted storage by creating a custom StorageClass. This guide explains how to set up encryption passphrase, create an encrypted storage class, and use it in applications.

LINSTOR provides at-rest encryption for persistent volumes using LUKS. This ensures that data stored on disk is encrypted and can only be accessed when the volume is mounted and unlocked.

Set Up Encryption in LINSTOR

To start using encryption, set up an encryption passphrase in LINSTOR.

Storage Subsystem Guides on Cozystack

Preparing Disks for LINSTOR Storage Pools

Problem Description

Symptoms

Diagnostics

Set up LINSTOR alias

Configuring a Dedicated Network for LINSTOR

Introduction

Configuring DRBD Resync Controller in LINSTOR

Recommended Settings for 10G Networks

Using NFS shares with Cozystack

Enable NFS driver

Export share

Configure connection

Order volume

Creating Encrypted Storage on LINSTOR

Set Up Encryption in LINSTOR