| XBD(4) | Device Drivers Manual (xen) | XBD(4) | 
xbd —
xbd* at xenbus?
xbd interface forms the frontend part of the
  paravirtualized drivers used by Xen guest domains to have a block device
  interface.
From a guest point of view, xbd is similar
    to a hard disk, and can be treated in the very same way regarding
    partitioning, file systems creation and usage, and mounting. By default, a
    NetBSD guest domain will assume that
    “xbd0a” serves as the root file system.
When the host is NetBSD, the
    xbd interface is backed by a
    xbdback(4) interface. In the
    XenStore, xbd and xbdback
    are identified by “vbd” (virtual block device) entries.
xbd
      interface.xbd block device, its
      sector size and total number of sectors.xbd device
      does not support cache flushing operation. This can be problematic for
      file system operations that require cache sync to avoid data loss or
      corruption.xbd driver first appeared in NetBSD
  3.0.
xbd driver was written by Manuel
  Bouyer
  <bouyer@NetBSD.org>.
| January 8, 2011 | NetBSD 9.4 |