Configurazione Cluster HA a 2 nodi con DRBD, Pacemaker, Corosync, LVM e iSCSI

cluster_storage_proxmox.md

# Configurazione Cluster HA a 2 nodi con DRBD, Pacemaker, Corosync, LVM e iSCSI

## Prerequisiti
- Due server con:
  - 2 interfacce di rete (1 per Proxmox, 1 per DRBD punto-punto)
  - Disco RAID hardware con strip size 128k
  - OS Linux (Debian/Ubuntu)
  - Connessione diretta 10GbE tra nodi

## 1. Configurazione Rete

```bash
# Nodo1
sudo ip addr add 192.168.100.1/30 dev eth1
sudo ip link set eth1 up

# Nodo2
sudo ip addr add 192.168.100.2/30 dev eth1
sudo ip link set eth1 up

# Verifica
ping 192.168.100.2  # Da nodo1 a nodo2

2. Installazione Pacchetti

sudo apt-get update
sudo apt-get install -y drbd-utils pacemaker corosync lvm2 targetcli-fb pcs

3. Configurazione DRBD

File /etc/drbd.d/r0.res:

resource r0 {
  protocol C;
  meta-disk internal;
  device /dev/drbd0;
  disk /dev/sdb1;
  handlers {
    pri-on-incon-degr "/usr/lib/drbd/notify-pri-on-incon-degr.sh; echo b > /proc/sysrq-trigger ; reboot -f";
    pri-lost-after-sb "/usr/lib/drbd/notify-pri-lost-after-sb.sh; echo b > /proc/sysrq-trigger ; reboot -f";
  }
  net {
    cram-hmac-alg "sha1";
    shared-secret "miapasswordsegreta";
  }
  on nodo1 {
    address 192.168.100.1:7788;
  }
  on nodo2 {
    address 192.168.100.2:7788;
  }
}

Inizializzazione DRBD:

sudo drbdadm create-md r0
sudo drbdadm up r0
# Sul nodo primario:
sudo drbdadm primary --force r0

4. Configurazione Pacemaker con PCS

# Autenticazione cluster
sudo pcs cluster auth nodo1 nodo2 -u hacluster -p miapasword

# Setup cluster
sudo pcs cluster setup --name cluster_iscsi nodo1 nodo2
sudo pcs cluster start --all
sudo pcs cluster enable --all

# Configurazione base
sudo pcs property set stonith-enabled=false
sudo pcs property set no-quorum-policy=ignore

5. Risorse Cluster

# Risorse DRBD
sudo pcs resource create p_drbd_r0 ocf:linbit:drbd drbd_resource=r0 op monitor interval=15s
sudo pcs resource master ms_drbd_r0 p_drbd_r0 master-max=1 master-node-max=1 clone-max=2 clone-node-max=1 notify=true

# LVM
sudo pcs resource create p_lvm_iscsi ocf:heartbeat:LVM volgrpname=vg_iscsi op monitor interval=10s timeout=30s

# iSCSI
sudo pcs resource create p_iscsi_target ocf:heartbeat:iSCSITarget iqn="iqn.2023-06.com.example:storage.iscsi" implementation="tgt"
sudo pcs resource create p_iscsi_lun ocf:heartbeat:iSCSILogicalUnit target_iqn="iqn.2023-06.com.example:storage.iscsi" lun=1 path="/dev/vg_iscsi/lv_iscsi"

6. Vincoli Cluster

sudo pcs constraint colocation add p_iscsi_target p_iscsi_lun p_lvm_iscsi with ms_drbd_r0 INFINITY
sudo pcs constraint order promote ms_drbd_r0 then start p_lvm_iscsi
sudo pcs constraint order start p_lvm_iscsi then start p_iscsi_target

7. Configurazione iSCSI Target

sudo targetcli backstores/block create name=iscsi_backend dev=/dev/vg_iscsi/lv_iscsi
sudo targetcli iscsi/ create iqn.2023-06.com.example:storage.iscsi
sudo targetcli saveconfig

Comandi Utili

# Stato cluster
sudo pcs status
sudo drbdadm status

# Failover manuale
sudo pcs resource move ms_drbd_r0 nodo2
sudo pcs resource clear ms_drbd_r0

Note Finali

1. Sostituire tutti i valori placeholder con i propri dati reali
2. La sincronizzazione iniziale DRBD può richiedere tempo
3. Testare il failover in ambiente non produttivo prima