diff --git a/proxmox/templates/debian_bullseye.json b/proxmox/templates/debian_bullseye.json
--- a/proxmox/templates/debian_bullseye.json
+++ b/proxmox/templates/debian_bullseye.json
@@ -22,7 +22,7 @@
       "username": "{{ user `username` }}",
       "password": "{{ user `password` }}",
       "node": "{{ user `proxmox_node` }}",
-      "vm_id": 10006,
+      "vm_id": 10007,
       "memory": 1024,
       "sockets": "1",
       "cores": 2,
@@ -45,8 +45,8 @@
       "cloud_init": "true",
       "cloud_init_storage_pool": "proxmox",
 
-      "iso_url": "https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-11.2.0-amd64-netinst.iso",
-      "iso_checksum": "45c9feabba213bdc6d72e7469de71ea5aeff73faea6bfb109ab5bad37c3b43bd",
+      "iso_url": "https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-11.3.0-amd64-netinst.iso",
+      "iso_checksum": "7892981e1da216e79fb3a1536ce5ebab157afdd20048fe458f2ae34fbc26c19b",
       "iso_storage_pool": "proxmox-cephfs",
       "unmount_iso": "true",
 
@@ -79,14 +79,14 @@
           "grub-installer/bootdev=/dev/vda <wait>",
           "<enter><wait>"
       ],
-      
+
       "ssh_host": "{{ user `ip` }}",
 
       "ssh_username": "installer",
       "ssh_timeout": "15m",
       "ssh_password": "installer",
 
-      "template_name": "debian-bullseye-11.2-{{ user `template-suffix` }}",
+      "template_name": "debian-bullseye-11.3-{{ user `template-suffix` }}",
       "template_description": "debian bullseye, generated on {{ user `template-date` }}"
     }
   ],
diff --git a/proxmox/templates/scripts/post-install.sh b/proxmox/templates/scripts/post-install.sh
--- a/proxmox/templates/scripts/post-install.sh
+++ b/proxmox/templates/scripts/post-install.sh
@@ -16,7 +16,9 @@
 export DEBIAN_FRONTEND=noninteractive
 
 apt-get update
-apt-get install -y man wget curl telnet net-tools dnsutils traceroute unbound gpg aptitude
+apt-get upgrade -y
+apt-get install -y man wget curl telnet net-tools dnsutils traceroute unbound \
+        gpg aptitude
 aptitude -y install "?priority(standard)!~i?archive(stable)"
 
 ####
diff --git a/proxmox/terraform/modules/node/variables.tf b/proxmox/terraform/modules/node/variables.tf
--- a/proxmox/terraform/modules/node/variables.tf
+++ b/proxmox/terraform/modules/node/variables.tf
@@ -20,9 +20,14 @@
 }
 
 variable "template" {
-  description = "Template created by packer to use (template-debian-10, debian-buster-...)"
+  description = "Debian image template created by packer"
+  # Note: use "buster" template for node with swh services (storage, objstorage, ...).
+  # You can use latest "bullseye" templates otherwise.
   type        = string
-  default     = "debian-buster-2020-11-06"
+  default     = "debian-buster-10.10-2021-09-09"
+  # other possible template values:
+  # - debian-bullseye-2022-04-21
+  # - debian-bullseye-zfs-2022-04-21 (for extra zfs dependencies)
 }
 
 variable "sockets" {
diff --git a/proxmox/terraform/staging/staging.tf b/proxmox/terraform/staging/staging.tf
--- a/proxmox/terraform/staging/staging.tf
+++ b/proxmox/terraform/staging/staging.tf
@@ -403,7 +403,7 @@
 
 module "maven-exporter0" {
   source      = "../modules/node"
-  template    = "debian-bullseye-11.0-2021-09-09" # otherwise to use more recent template
+  template    = "debian-bullseye-11.3-2022-04-21"
   vmid        = 122
   config      = local.config
   hostname    = "maven-exporter0"