XBD(4) | Device Drivers Manual (xen) | XBD(4)

# NAME

`xbd` — Xen frontend paravirtualized block device interface

# SYNOPSIS

`xbd* at xenbus?`

# DESCRIPTION

The `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.

# DIAGNOSTICS

xbd%d: using event channel %d
  Specifies the event channel used by this `xbd` interface.
xbd%d: %s MB, %d bytes/sect x %u sectors
  Gives the total size of the `xbd` block device, its sector size and total number of sectors.
xbd%d: WARNING: cache flush not supported by backend
  The backend driver associated with this `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.

# SEE ALSO

xbdback(4), xenbus(4), dkctl(8)

# HISTORY

The `xbd` driver first appeared in NetBSD 3.0.

# AUTHORS

The `xbd` driver was written by Manuel Bouyer <bouyer@NetBSD.org>.

January 8, 2011 | NetBSD 11.99