diff --git a/ohpc-instance/main.tf b/ohpc-instance/main.tf
index f9686296cefca24b84a3e31793768d8f62ed2f5a..55ca66011b364ebf331eedd7e38e94b263b7e331 100644
--- a/ohpc-instance/main.tf
+++ b/ohpc-instance/main.tf
@@ -26,7 +26,10 @@ variable "floating_ip_ohpc" {type = string}
 
 variable "ohpc_user" {}
 variable "ssh_private_key" {}
-variable "vol_id" {}
+variable "vol_ids" {
+  type    = list(string)
+  default = []
+}
 
 # creates details for the OHPC instance
 resource "openstack_compute_instance_v2" "ohpc" {
@@ -63,8 +66,9 @@ resource "openstack_compute_floatingip_associate_v2" "ohpc" {
 
 # Attach a volume
 resource "openstack_compute_volume_attach_v2" "volume_attach" {
+  count       = length(var.vol_ids)
   instance_id = openstack_compute_instance_v2.ohpc.id
-  volume_id   = var.vol_id
+  volume_id   = var.vol_ids[count.index]
 }
 
 output "xdmod_instance_id" {