diff --git a/cloudinit/config/cc_disk_setup.py b/cloudinit/config/cc_disk_setup.py
index 7f85a3a5375..5bdd51b7843 100644
--- a/cloudinit/config/cc_disk_setup.py
+++ b/cloudinit/config/cc_disk_setup.py
@@ -10,6 +10,7 @@
 import logging
 import os
 import shlex
+from pathlib import Path
 from textwrap import dedent
 
 from cloudinit import subp, util
@@ -915,7 +916,14 @@ def mkfs(fs_cfg):
     if not partition or partition.isdigit():
         # Handle manual definition of partition
         if partition.isdigit():
+            if device[-1].isdigit():
+                device = f"{device}p"
             device = "%s%s" % (device, partition)
+            if not Path(device).is_block_device():
+                LOG.warning(
+                    "Path %s does not exist or is not a block device"
+                )
+                return
             LOG.debug(
                 "Manual request of partition %s for %s", partition, device
             )