Running PostgreSQL on Kubernetes Using iSCSI External Storage

General Discussions
1

Hello Kubernetes community,

I am currently facing challenges in deploying PostgreSQL on Kubernetes with iSCSI external storage.

Environment:

  • Kubernetes Version:
    1. Client Version: v1.28.4
    2. Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
    3. Server Version: v1.28.4
  • PostgreSQL Version: latest
  • Operating System on Kubernetes Nodes: Ubuntu 20.04

PostgreSQL Deployment:

Create a new YAML configuration (postgres-pv.yaml) file

apiVersion: v1
kind: PersistentVolume
metadata:
  name: postgres-pv
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  iscsi:
    targetPortal: 192.168.1.1:3260
    iqn: iqn.1991-05.com.microsoft:win-volti8mk571-pgdata5-target
    lun: 0
    fsType: ext4
  persistentVolumeReclaimPolicy: Retain

Create a new YAML configuration (postgres-pvc.yaml) file

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: postgres-pvc
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi

Create a new YAML configuration (postgres-deployment.yaml) file

apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgres
  template:
    metadata:
      labels:
        app: postgres
    spec:
      containers:
        - name: postgres
          image: postgres:latest
          env:
            - name: POSTGRES_USER
              value: <YOUR_DB_USER>
            - name: POSTGRES_PASSWORD
              value: <YOUR_DB_PASSWORD>
            - name: POSTGRES_DB
              value: <YOUR_DB_NAME>
          volumeMounts:
            - name: postgres-storage
              mountPath: /var/lib/postgresql/data
      volumes:
        - name: postgres-storage
          persistentVolumeClaim:
            claimName: postgres-pvc

Apply the YAML files to your Kubernetes cluster:

1. kubectl apply -f postgres-pv.yaml
2. kubectl apply -f postgres-pvc.yaml
3. kubectl apply -f postgres-deployment.yaml

i have facing the problem below mention

> kubectl logs postgres-8ff8f8d9f-5g4hb

Defaulted container "postgres" out of: postgres, init-db (init)
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.

The database cluster will be initialized with locale "en_US.utf8".
The default database encoding has accordingly been set to "UTF8".
The default text search configuration will be set to "english".

Data page checksums are disabled.

initdb: error: directory "/var/lib/postgresql/data" exists but is not empty
initdb: detail: It contains a lost+found directory, perhaps due to it being a mount point.
initdb: hint: Using a mount point directly as the data directory is not recommended.
Create a subdirectory under the mount point.

how to resolve the problem or any other solution, as soon as possible

2

Hi @Sardonyxtechsupport It’s already too late for me to reply; however, can you please try including this argument after the PostgreSQL image and check if it works for you?

containers:

  • name: postgres
    image: postgres:16.0
    args:
    • “-c”
    • “data_directory=/var/lib/postgresql/data”