my $string = "Rückantwort";

my @parts = split /\n\n/,$string;
for my $part ( @parts ){
    next unless $part =~ m!^\s*Volume!;
    print $part;
}

my $file = '/path/to/file';

{
    local $/ = "\n\n";
    open my $fh,'<',$file or die $!;
    while( my $entry = <$fh> ){
        next unless $entry =~ m!^\s*Volume!;
        print $entry;
    }
}

 open (VOL, "$ssh $filer aggr show_space $aggr |") || die "Cannot connect to $filer: $! \n";
 while (<VOL>)
        {
         chomp (my $r3="$_");
         my @parts = split /\n\n/,$r3;
         for my $part (@parts)
         {
          next unless $part =~ m!^\s*Volume!;
          print ("Habe: $part\n");
         }
        #print ("Lese $r3 \n");
        } # end while VOL
close (VOL);

 open (VOL, "$ssh $filer aggr show_space $aggr |") || die "Cannot connect to $filer: $! \n";
while (my $line = <VOL>){
    if( $line =~ /^\s*Volume/ ){
        $bool = 1;
    }

    next unless $bool;

    print $line;

    if( $line =~ /^\n+$/ ){
        $bool = 0;
    }
} # end while VOL
close (VOL);

 my $string = "";
open (VOL, "$ssh $filer aggr show_space $aggr |") || die "Cannot connect to $filer: $! \n";
while (my $line = <VOL>)
{
    $string .= $line;
} # end while VOL
close (VOL);

my @parts = split /\n\n/,$string;
for my $part (@parts){
     next unless $part =~ m!^\s*Volume!;
     print ("Habe: $part\n");
}