I'm using SLES 11 SP2 to Dom0, and SLED 11SP1 in DomU.
In domU, I have disk "/dev/xvdf: 96.6 GB" in dom0 is a pv02 PV-LVM.
After pv02 enlarge and see it reflected in domU:/dev/xvdf created a new partition with the free space of the form:

     # fdisk -l /dev/xvdf
    Disk /dev/xvdf: 98.8 GB, 98784247808 bytes
    255 heads, 63 sectors/track, 12009 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Disk identifier: 0x00000000

      Device Boot      Start         End      Blocks   Id  System
    /dev/xvdf1   *           1       11748    94365778+  8e  Linux LVM
    /dev/xvdf2           11749       12009     2096482+  8e  Linux LVM

After creating the partition, I see that udev does not create /dev/xvdf2, I try to create with "mknod /dev/xvdf2 b 202 82", but this does not work properly (I can not format the partition)

 # mkfs.ext3 /dev/xvdf2
mke2fs 1.41.9 (22-Aug-2009)
mkfs.ext3: No such device or address while trying to determine filesystem size

in /proc/ partitions does not appear xvdf2.
udev restart (/ etc / init.d / boot.udev force-reload) but fails to do walk /dev/xvdf2.
Need to shut down the domU to work, configure udev:

 # ls-lh / dev / xvdf *
             brw-rw ---- 1 root disk 202, 80 October 10 19:29 /dev/ xvdf
             brw-rw ---- 1 root disk 202, 81 October 10 18:26 /dev/xvdf1
             brw-rw ---- 1 root disk 202, 82 October 10 20:28 /dev/xvdf2

I feel abnormal having to power down the domU to take the device .. (linux reboots ignorantly)
The strangest thing is that try to do the same (after restart) and I generates udev /dev/ correctly.
I missed doing the first time?

Thanks for getting this far (sorry for using translate)