How to attach and mount Xen DomU’s disk to Dom0
To attach phy:vg_xen/vm-10.1.1.228 to xvda on Domain-0:
# xm block-attach Domain-0 phy:vg_xen/vm-10.1.1.228 xvda w
Mount the new partition /dev/xvda2 to /mnt/xvda2:
# mount /dev/xvda2 /mnt/xvda2
After finishing using the partition, umount it and detach it:
# umount /mnt/xvda2/
# xm block-detach Domain-0 xvda