diff --git a/deployment/proxmox/provision.sh b/deployment/proxmox/provision.sh
index 39d74ac1..30f5f6fc 100755
--- a/deployment/proxmox/provision.sh
+++ b/deployment/proxmox/provision.sh
@@ -1,32 +1,42 @@
 #!/usr/bin/env sh
 set -euC
 
+################################################################################
+## Constants
+
+readonly apiurl=https://192.168.51.81:8006/api2/json
+
+## FIXME: There seems to be a problem with file upload where the task is
+## registered to `node051` no matter what node we are actually uploading to? For
+## now, let us just use `node051` everywhere.
+readonly node=node051
+
+readonly tmpdir=/tmp/proxmox-provision-$RANDOM$RANDOM
+mkdir $tmpdir
+
 ################################################################################
 ## Parse arguments
 
 username=
 password=
-iso=result/iso/installer.iso
 sockets=1
 cores=1
 memory=2048
-vmid=
+vmids=
 
 help () {
   cat <<EOF
-Usage: $0 [OPTION...]
+Usage: $0 [OPTION...] [ID...]
 
-Required:
+Authentication options:
   --username STR    Username, with provider (eg. niols@pve)
   --password STR    Password
-  --vmid INT        Identifier of the VM
 
   If not provided via the command line, username and password will be looked for
   in a '.proxmox' file in the current working directory, the username on the
   first line, and the password on the second.
 
-Optional:
-  --iso PATH        Installer ISO (default: $iso)
+Other options:
   --sockets INT     Number of sockets (default: $sockets)
   --cores INT       Number of cores (default: $cores)
   --memory INT      Memory (default: $memory)
@@ -44,15 +54,16 @@ while [ $# -gt 0 ]; do
   case $argument in
     --username) readonly username=$1; shift ;;
     --password) readonly password=$1; shift ;;
-    --vmid) readonly vmid=$1; shift ;;
 
-    --iso) iso=$1; shift ;;
     --sockets) sockets=$1; shift ;;
     --cores) cores=$1; shift ;;
     --memory) memory=$1; shift ;;
 
     -h|-\?|--help) help; exit 0 ;;
-    *) die 'Unknown argument: `%s`.' "$argument" ;;
+
+    -*) die 'Unknown argument: `%s`.' "$argument" ;;
+
+    *) vmids="$vmids $argument" ;;
   esac
 done
 
@@ -64,32 +75,22 @@ if [ -z "$username" ] || [ -z "$password" ]; then
   fi
 fi
 
-[ -z "$vmid" ] && die 'Required: `--vmid`.\n'
-
-printf 'Provisioning VM %d with:\n' $vmid
-
-readonly iso
 readonly sockets
 readonly cores
 readonly memory
 
-printf '  iso: %s\n' $iso
-printf '  sockets: %d\n' $sockets
-printf '  cores: %d\n' $cores
-printf '  memory: %d\n' $memory
+## FIXME: When we figure out how to use other nodes than node051.
+# if [ -z "$node" ]; then
+#   printf 'Picking random node...'
+#   proxmox GET $apiurl/nodes
+#   node=$(from_response .data[].node | sort -R | head -n 1)
+#   printf ' done. Picked `%s`.\n' "$node"
+# fi
+# readonly node
 
 ################################################################################
 ## Getting started
 
-readonly apiurl=https://192.168.51.81:8006/api2/json
-
-## FIXME: There seems to be a problem with file upload where the task is
-## registered to `node051` no matter what node we are actually uploading to? For
-## now, let us just use `node051` everywhere.
-node=node051
-
-from_response () { echo "$response" | jq -r "$1"; }
-
 printf 'Authenticating...'
 response=$(
     http \
@@ -98,120 +99,165 @@ response=$(
         "username=$username" \
         "password=$password"
     )
-readonly csrfToken=$(from_response .data.CSRFPreventionToken)
-readonly ticket=$(from_response .data.ticket)
+readonly ticket=$(echo "$response" | jq -r .data.ticket)
+readonly csrfToken=$(echo "$response" | jq -r .data.CSRFPreventionToken)
 printf ' done.\n'
 
-http_ () {
-  response=$(
-    http \
-      --verify no \
-      "$@" \
-      "Cookie:PVEAuthCookie=$ticket" \
-      "CSRFPreventionToken:$csrfToken"
-  )
+proxmox () {
+  http \
+    --form \
+    --verify no \
+    "$@" \
+    "Cookie:PVEAuthCookie=$ticket" \
+    "CSRFPreventionToken:$csrfToken"
 }
 
-wait_ () {
-  upid=$1
+## Synchronous variant for when the `proxmox` function would just respond an
+## UPID in the `data` JSON field.
+proxmox_sync () {
+  response=$(proxmox "$@")
+  upid=$(echo "$response" | jq -r .data)
   while :; do
-    http_ GET $apiurl/nodes/$node/tasks/$upid/status
-    status=$(from_response .data.status)
+    response=$(proxmox GET $apiurl/nodes/$node/tasks/$upid/status)
+    status=$(echo "$response" | jq -r .data.status)
     case $status in
-      running) printf '.'; sleep 1 ;;
+      running) sleep 1 ;;
       stopped) break ;;
-      *) printf ' unexpected status: `%s`\n' "$status"; exit 2 ;;
+      *) die 'unexpected status: `%s`' "$status" ;;
     esac
   done
 }
 
+################################################################################
+## Build ISO
+
+build_iso () {
+  printf 'Building ISO for VM %d...\n' $1
+
+  nix build \
+    .#isoInstallers.provisioning.fedi$1 \
+    --log-format raw --quiet \
+    --out-link $tmpdir/installer-fedi$1
+
+  ln -sf $tmpdir/installer-fedi$1/iso/installer.iso $tmpdir/installer-fedi$1.iso
+
+  printf 'done building ISO for VM %d.\n' $1
+}
+
 ################################################################################
 ## Upload ISO
 
-if [ -z "$node" ]; then
-  printf 'Picking random node...'
-  http_ GET $apiurl/nodes
-  node=$(from_response .data[].node | sort -R | head -n 1)
-  printf ' done. Picked `%s`.\n' "$node"
-fi
-readonly node
+upload_iso () {
+  printf 'Uploading ISO for VM %d...\n' $1
 
-absiso=$(cd "$(dirname "$iso")"; pwd)/$(basename "$iso")
-readonly isoname=installer-$vmid.iso
+  proxmox_sync POST $apiurl/nodes/$node/storage/local/upload \
+    filename@$tmpdir/installer-fedi$1.iso \
+    content==iso
 
-printf 'Uploading ISO...'
-ln -sf $absiso /tmp/$isoname
-http_ --form POST $apiurl/nodes/$node/storage/local/upload \
-  filename@/tmp/$isoname \
-  content==iso
-rm /tmp/$isoname
-wait_ $(from_response .data)
-printf ' done.\n'
+  printf 'done uploading ISO for VM %d.\n' $1
+}
+
+################################################################################
+## Remove ISO
+
+remove_iso () {
+  printf 'Removing ISO for VM %d... unsupported for now. (FIXME)\n' $1
+}
 
 ################################################################################
 ## Create VM
 
-printf 'Creating VM...'
+create_vm () {
+  printf 'Creating VM %d...\n' $1
 
-http_ --form POST $apiurl/nodes/$node/qemu \
-  \
-  vmid==$vmid \
-  name==$(printf 'fedi%03d' $vmid) \
-  pool==Fediversity \
-  \
-  ide2=="local:iso/$isoname,media=cdrom" \
-  ostype==l26 \
-  \
-  bios==ovmf \
-  efidisk0=='linstor_storage:1,efitype=4m' \
-  agent==1 \
-  \
-  scsihw==virtio-scsi-single \
-  scsi0=='linstor_storage:32,discard=on,ssd=on,iothread=on' \
-  \
-  sockets==$sockets \
-  cores==$cores \
-  cpu==x86-64-v2-AES \
-  numa==1 \
-  \
-  memory==$memory \
-  \
-  net0=='virtio,bridge=vnet1306'
+  proxmox_sync POST $apiurl/nodes/$node/qemu \
+    \
+    vmid==$1 \
+    name=="fedi$1" \
+    pool==Fediversity \
+    \
+    ide2=="local:iso/installer-fedi$1.iso,media=cdrom" \
+    ostype==l26 \
+    \
+    bios==ovmf \
+    efidisk0=='linstor_storage:1,efitype=4m' \
+    agent==1 \
+    \
+    scsihw==virtio-scsi-single \
+    scsi0=='linstor_storage:32,discard=on,ssd=on,iothread=on' \
+    \
+    sockets==$sockets \
+    cores==$cores \
+    cpu==x86-64-v2-AES \
+    numa==1 \
+    \
+    memory==$memory \
+    \
+    net0=='virtio,bridge=vnet1306'
 
-wait_ $(from_response .data)
-printf ' done.\n'
+  printf 'done creating VM %d.\n' $1
+}
 
 ################################################################################
 ## Install VM
 
-printf 'Installing VM...'
+install_vm () {
+  printf 'Installing VM %d...\n' $1
 
-http_ POST $apiurl/nodes/$node/qemu/$vmid/status/start
-wait_ $(from_response .data)
+  proxmox_sync POST $apiurl/nodes/$node/qemu/$1/status/start
 
-while :; do
-  http_ GET $apiurl/nodes/$node/qemu/$vmid/status/current
-  status=$(from_response .data.status)
-  case $status in
-    running) printf '.'; sleep 1 ;;
-    stopped) break ;;
-    *) printf ' unexpected status: `%s`\n' "$status"; exit 2 ;;
-  esac
-done
+  while :; do
+    response=$(proxmox GET $apiurl/nodes/$node/qemu/$1/status/current)
+    status=$(echo "$response" | jq -r .data.status)
+    case $status in
+      running) sleep 1 ;;
+      stopped) break ;;
+      *) printf ' unexpected status: `%s`\n' "$status"; exit 2 ;;
+    esac
+  done
 
-printf ' done.\n'
+  printf 'done installing VM %d.\n' $1
+}
 
 ################################################################################
 ## Start VM
 
-printf 'Starting VM...'
+start_vm () {
+  printf 'Starting VM %d...\n' $1
 
-http_ --form POST $apiurl/nodes/$node/qemu/$vmid/config \
-  ide2=='none,media=cdrom' \
-  net0=='virtio,bridge=vnet1305'
-wait_ $(from_response .data)
+  proxmox_sync POST $apiurl/nodes/$node/qemu/$1/config \
+    ide2=='none,media=cdrom' \
+    net0=='virtio,bridge=vnet1305'
 
-http_ POST $apiurl/nodes/$node/qemu/$vmid/status/start
-wait_ $(from_response .data)
+  proxmox_sync POST $apiurl/nodes/$node/qemu/$1/status/start
 
-printf ' done.\n'
+  printf 'done starting VM %d.\n' $1
+}
+
+################################################################################
+## Main loop
+
+printf 'Provisioning VMs%s with:\n' "$vmids"
+printf '  sockets: %d\n' $sockets
+printf '  cores: %d\n' $cores
+printf '  memory: %d\n' $memory
+
+provision_vm () {
+  build_iso $1
+  upload_iso $1
+  create_vm $1
+  install_vm $1
+  start_vm $1
+  remove_iso $1
+}
+
+for vmid in $vmids; do
+  provision_vm $vmid
+done
+
+printf 'done provisioning VMs%s.\n' "$vmids"
+
+################################################################################
+## Cleanup
+
+rm -Rf $tmpdir