diff --git a/TODO b/TODO
index 972d5ca..20fad5e 100644
--- a/TODO
+++ b/TODO
@@ -28,6 +28,19 @@ Bugs to fix and features to add for 5.0
    are examples, and shouldn't cover every single scenario. They
    are also easy to write.
 
+* Think again about disk_device checks :
+
+   Newer Xen provides "xvda", older provided "sda". The current check for
+   valid values of disk_device (used for root device in domU /etc/fstab)
+   does only allow those values.
+   This forbids any deployment of LVM/RAID _inside_ domU, which cannot
+   be created by xen-tools anyway. So the current check is fine with the
+   current possibilities of xen-tools, but could become a limitation.
+   - Is it possible/wanted to "query" xend for default device names ?
+   - Is it possible to create /dev/mapper devices with xend conf ?
+   - Can we just avoid to ask for this value and not specify the device
+   in /etc/fstab (and use /dev/root, /dev/by-uuid, or anything ?)
+
 * xen-create-image --dist=... / sources.list generation should be more fine-grained
 
    xen-tools should offer the possibility to enable/disable
diff --git a/bin/xen-create-image b/bin/xen-create-image
index af4d4f5..06b8e92 100755
--- a/bin/xen-create-image
+++ b/bin/xen-create-image
@@ -1553,8 +1553,8 @@ sub checkOption
             message => "must be a serial device (tty*, hvc* or xvc*).\n",
         },
         diskDev => {
-            check   => qr/^(?:\/dev\/)?(?:tty|hvc)[0-9]+$/,
-            message => "must be a disk device (tty*, hvc*).\n",
+            check   => qr/^(?:\/dev\/)?(?:xvd|sd)[a-z][0-9]+$/,
+            message => "must be a disk device (xvd*, sd*).\n",
         },
         ipv4 => {
             check   => qr/^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/,
diff --git a/etc/xen-tools.conf b/etc/xen-tools.conf
index cdb9e75..d606c9d 100644
--- a/etc/xen-tools.conf
+++ b/etc/xen-tools.conf
@@ -298,7 +298,7 @@ btrfs_options    = defaults
 #
 #  If you're using the lenny or later version of the Xen guest kernel you will
 # need to make sure that you use 'hvc0' for the guest serial device,
-# and 'xvdX' instead of 'sdX' for serial devices.
+# and 'xvdX' instead of 'sdX' for disk devices.
 #
 #  You may specify the things to use here:
 #