NAME

       Sys::Virt::StorageVol - Represent & manage a libvirt storage volume

DESCRIPTION

       The "Sys::Virt::StorageVol" module represents a storage volume managed by libvirt. A
       storage volume is always associated with a containing storage pool
       ("Sys::Virt::StoragePool").

METHODS

       my $name = $vol->get_name()
           Returns a string with a locally unique name of the storage vol

       my $name = $vol->get_key()
           Returns a string with a globally unique key for the storage vol

       my $name = $vol->get_path()
           Returns a string with a locally unique file path of the storage vol

       my $xml = $vol->get_xml_description()
           Returns an XML document containing a complete description of the storage vol's
           configuration

       $vol->delete($flags)
           Immediately delete the storage volume freeing its storage resources.  The "flags"
           parameter indicates any special action to be taken when deleting the volume.

       $vol->resize($newcapacity, $flags=0)
           Adjust the size of the storage volume. The $newcapacity value semantics depend on the
           $flags parameter. If $flags specifies "RESIZE_DELTA" then the $newcapacity is relative
           to the current size. If $flags specifies "RESIZE_SHRINK" then the $newcapacity value
           is the amount of space to remove

       $vol->wipe($flags = 0)
           Clear the data in the storage volume to avoid future information leak. The "flags"
           parameter is currently unused and defaults to zero.

       $vol->wipe_pattern($algorithm, $flags = 0)
           Clear the data in the storage volume to avoid future information leak. The $algorithm
           parameter specifies the data pattern used to erase data, and should be one of the WIPE
           ALGORITHM CONSTANTS listed later. The "flags" parameter is currently unused and
           defaults to zero.

       my $info = $vol->get_info($flags = 0)
           Retrieve live information about the storage volume. The returned $info hash reference
           contains three keys. "type" indicates whether the volume is a file or block device.
           "capacity" provides the maximum logical size of the volume. "allocation" provides the
           current physical usage of the volume. The allocation may be less than the capacity for
           sparse, or grow-on-demand volumes. The allocation may also be larger than the
           capacity, if there is a metadata overhead for the volume format. $flags may take one
           of the values

           Sys::Virt::StorageVol::USE_ALLOCATION
               Return the current allocation in allocation

           Sys::Virt::StorageVol::GET_PHYSICAL
               Return the physical size in allocation

       $vol->download($st, $offset, $length, $flags=0);
           Download data from $vol using the stream $st. If $offset and $length are non-zero,
           then restrict data to the specified volume byte range. The $flags accept the following
           values:

           Sys::Virt::StorageVol::VOL_DOWNLOAD_SPARSE_STREAM
               If this flag is is set in @flags effective transmission of holes is enabled. This
               assumes using the stream $st with combination of "sparse_recv_all" or "recv($flags
               = VIR_STREAM_RECV_STOP_AT_HOLE)" for honouring holes sent by server.

       $vol->upload($st, $offset, $length, $flags=0);
           Upload data to $vol using the stream $st. If $offset and $length are non-zero, then
           restrict data to the specified volume byte range. The $flags accept the following
           values:

           Sys::Virt::StorageVol::VOL_UPLOAD_SPARSE_STREAM
               If this is set in $flags effective transmission of holes is enabled. This assumes
               using the stream $st with combination of "sparse_send_all" or "send_hole" to
               preserve source file sparseness.

CONSTANTS

       The following sets of constants are useful when dealing with storage volumes

   VOLUME TYPES
       The following constants are useful for interpreting the "type" field in the hash returned
       by the "get_info" method

       Sys::Virt::StorageVol::TYPE_FILE
           The volume is a plain file

       Sys::Virt::StorageVol::TYPE_BLOCK
           The volume is a block device

       Sys::Virt::StorageVol::TYPE_DIR
           The volume is a directory

       Sys::Virt::StorageVol::TYPE_NETWORK
           The volume is a network source

       Sys::Virt::StorageVol::TYPE_NETDIR
           The volume is a network directory

       Sys::Virt::StorageVol::TYPE_PLOOP
           The volume is a ploop directory

   CREATE MODES
       The following constants are useful for the "flags" parameter of the "create" method

       Sys::Virt::StorageVol::CREATE_PREALLOC_METADATA
           Preallocate header metadata when creating the volume.

       Sys::Virt::StorageVol::CREATE_REFLINK
           Perform lightweight reference copy

   DELETE MODES
       The following constants are useful for the "flags" parameter of the "delete" method

       Sys::Virt::StorageVol::DELETE_NORMAL
           Do a plain delete without any attempt to scrub data.

       Sys::Virt::StorageVol::DELETE_ZEROED
           Zero out current allocated blocks when deleting the volume

       Sys::Virt::StorageVol::DELETE_WITH_SNAPSHOTS
           Delete snapshots associated with the volume

   WIPE ALGORITHM CONSTANTS
       The following constants specify the algorithm for erasing data

       Sys::Virt::StorageVol::WIPE_ALG_BSI
           9-pass method recommended by the German Center of Security in Information Technologies

       Sys::Virt::StorageVol::WIPE_ALG_DOD
           4-pass Dod 5220.22-M section, 8-306 procedure

       Sys::Virt::StorageVol::WIPE_ALG_GUTMANN
           The canonical 35-pass sequence

       Sys::Virt::StorageVol::WIPE_ALG_NNSA
           4-pass NNSA Policy Letter NAP-14.1-C (XVI-8)

       Sys::Virt::StorageVol::WIPE_ALG_PFITZNER7
           7-pass random

       Sys::Virt::StorageVol::WIPE_ALG_PFITZNER33
           33-pass random

       Sys::Virt::StorageVol::WIPE_ALG_RANDOM
           1-pass random

       Sys::Virt::StorageVol::WIPE_ALG_SCHNEIER
           7-pass method described by Bruce Schneier in "Applied Cryptography" (1996)

       Sys::Virt::StorageVol::WIPE_ALG_ZERO
           1-pass, all zeroes

       Sys::Virt::StorageVol::WIPE_ALG_TRIM
           1-pass, trim all data on the volume by using TRIM or DISCARD

       VOLUME RESIZE CONSTANTS

       The following constants control how storage volumes can be resized

       Sys::Virt::StorageVol::RESIZE_ALLOCATE
           Fully allocate the extra space required during resize

       Sys::Virt::StorageVol::RESIZE_DELTA
           Treat the new capacity as a delta to the current capacity

       Sys::Virt::StorageVol::RESIZE_SHRINK
           Treat the new capacity as an amount to remove from the capacity

AUTHORS

       Daniel P. Berrange <berrange@redhat.com>

COPYRIGHT

       Copyright (C) 2006-2009 Red Hat Copyright (C) 2006-2009 Daniel P. Berrange

LICENSE

       This program is free software; you can redistribute it and/or modify it under the terms of
       either the GNU General Public License as published by the Free Software Foundation (either
       version 2 of the License, or at your option any later version), or, the Artistic License,
       as specified in the Perl README file.

SEE ALSO

       Sys::Virt, Sys::Virt::Error, "http://libvirt.org"