use strict;
use warnings;
use Data::Dumper;

my %hash;
open ( FH, "powermt display dev=all|");# data stream comes from here

$/ = '';
while (<FH>) {
    my ($id) = ( $_ =~ /Logical device ID=(\w+)/ );
    push (@{$hash{$id}}, $1) if /(c\d+t\d+d\d+)/;
}

print Dumper (\%hash);