3.1.3

Amanda::Recovery::Scan


NAME

Amanda::Recovery::Scan -- interface to scan algorithm


SYNOPSIS

    use Amanda::Recovey::Scan;
    # scan the default changer with no interactivity
    my $scan = Amanda::Recovery::Scan->new();
    # ..or scan the changer $chg, using $interactive for interactivity
    $scan = Amanda::Recovery::Scan->new(chg => $chg,
                                        interactive => $interactive);
    $scan->find_volume(
        label => "TAPE-012",
        res_cb => sub {
            my ($err, $reservation) = @_;
            if ($err) {
                die "$err";
            }
            $dev = $reservation->{device};
            # use device..
        });
    # later..
    $reservation->release(finished_cb => $start_next_volume);
    
=head1 OVERVIEW

This package provides a way for programs that need to read data from volumes (loosely called "recovery" programs) to find the volumes they need in a configurable way. It takes care of prompting for volumes when they are not available, juggling multiple changers, and any other unpredictabilities.


INTERFACE

Like Amanda::Changer, this package operates asynchronously, and thus requires that the caller use Amanda::MainLoop to poll for events.

A new Scan object is created with the new function as follows:

  my $scan = Amanda::Recovery::Scan->new(scan_conf   => $scan_conf,
                                         chg         => $chg,
                                         interactive => $interactive);

scan_conf is the configuration for the scan, which at this point should be omitted, as configuration is not yet supported. The chg parameter specifies the changer to start the scan with. The default changer is used if chg is omitted. The interactive parameter gives an Amanda::Interactive object.

CALLBACKS

Many of the callbacks used by this package are identical to the callbacks of the same name in Amanda::Changer.

When a callback is called with an error, it is an object of type Amanda::Changer::Error. The volinuse reason has a different meaning: it means that the volume with that label is present in the changer, but is in use by another program.

Scan object

find_volume

  $scan->find_volume(label       => $label,
                     res_cb      => $res_cb,
                     user_msg_fn => $user_msg_fn,
                     set_current => 0)

Find the volume labelled $label and call $res_cb. $user_msg_fn is used to send progress information, The argumnet it takes are describe in the next section. As with the load method of the changer API, set_current should be set to 1 if you want the scan to set the current slot.

user_msg_fn

The user_msg_fn take various arguments

Initiate the scan of the slot $slot: $self->user_msg_fn(scan_slot => 1, slot => $slot);

Initiate the scan of the slot $slot which should have the label $label: $self->user_msg_fn(scan_slot => 1, slot => $slot, label => $label);

The result of scanning slot $slot: $self->user_msg_fn(slot_result => 1, slot => $slot, err => $err, res => $res);

Other options can be added at any time. The function can ignore them.


ABOUT THIS PAGE

This page was automatically generated Tue Nov 19 20:05:35 2013 from the Amanda source tree, and documents the most recent development version of Amanda. For documentation specific to the version of Amanda on your system, use the 'perldoc' command.


3.1.3