• Nikos Tsironis's avatar
    dm: add clone target · 7431b783
    Nikos Tsironis authored
    Add the dm-clone target, which allows cloning of arbitrary block
    devices.
    
    dm-clone produces a one-to-one copy of an existing, read-only source
    device into a writable destination device: It presents a virtual block
    device which makes all data appear immediately, and redirects reads and
    writes accordingly.
    
    The main use case of dm-clone is to clone a potentially remote,
    high-latency, read-only, archival-type block device into a writable,
    fast, primary-type device for fast, low-latency I/O. The cloned device
    is visible/mountable immediately and the copy of the source device to
    the destination device happens in the background, in parallel with user
    I/O.
    
    When the cloning completes, the dm-clone table can be removed altogether
    and be replaced, e.g., by a linear table, mapping directly to the
    destination device.
    
    For further information and examples of how to use dm-clone, please read
    Documentation/admin-guide/device-mapper/dm-clone.rst
    Suggested-by: default avatarVangelis Koukis <vkoukis@arrikto.com>
    Co-developed-by: default avatarIlias Tsitsimpis <iliastsi@arrikto.com>
    Signed-off-by: default avatarIlias Tsitsimpis <iliastsi@arrikto.com>
    Signed-off-by: default avatarNikos Tsironis <ntsironis@arrikto.com>
    Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
    7431b783
dm-clone.rst 12.8 KB