I'm having to do with an OpenShift RHEL Linux installation running on Amazon EC2. In the filesystem, there is a device file named
/dev/xvde1 mounted to
/ ... and a device file named
/dev/xvde2 mounted to
What is an xvdeN device file?
/dev/xvde is a xen virtual disk, and /dev/xvde1 and /dev/xvde2 are partitions on that virtual disk.
On the Xen host (the dom0), /dev/xvde could be a raw disk or disk partition, an LVM volume, a disk image file, an iscsi disk or something else.
From your VM's POV, that's completely irrelevant - just treat it the same as any other disk. It just happens to have a device name beginning with /dev/xvd rather than /dev/sd or /dev/hd or some other device name (device names and naming conventions are ultimately arbitrary anyway)
It's a Xen device. See e.g. Xen on Debian wiki